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Dr. Carleen Eaton

Dr. Carleen Eaton

Subcellular Structure

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Table of Contents

Section 1: Chemistry of Life
Elements, Compounds, and Chemical Bonds

56m 18s

Intro
0:00
Elements
0:09
Elements
0:48
Matter
0:55
Naturally Occurring Elements
1:12
Atomic Number and Atomic Mass
2:39
Compounds
3:06
Molecule
3:07
Compounds
3:14
Examples
3:20
Atoms
4:53
Atoms
4:56
Protons, Neutrons, and Electrons
5:29
Isotopes
10:42
Energy Levels of Electrons
13:01
Electron Shells
13:13
Valence Shell
13:22
Example: Electron Shells and Potential Energy
13:28
Covalent Bonds
19:52
Covalent Bonds
19:54
Examples
20:03
Polar and Nonpolar Covalent Bonds
23:54
Polar Bond
24:07
Nonpolar Bonds
24:17
Examples
24:25
Ionic Bonds
29:04
Ionic Bond, Cations, Anions
29:19
Example: NaCl
29:30
Hydrogen Bond
33:18
Hydrogen Bond
33:20
Chemical Reactions
35:36
Example: Reactants, Products and Chemical Reactions
35:45
Molecular Mass and Molar Concentration
38:45
Avogadro's Number and Mol
39:12
Examples: Molecular Mass and Molarity
42:10
Example 1: Proton, Neutrons and Electrons
47:05
Example 2: Reactants and Products
49:35
Example 3: Bonding
52:39
Example 4: Mass
53:59
Properties of Water

50m 23s

Intro
0:00
Molecular Structure of Water
0:21
Molecular Structure of Water
0:27
Properties of Water
4:30
Cohesive
4:55
Transpiration
5:29
Adhesion
6:20
Surface Tension
7:17
Properties of Water, cont.
9:14
Specific Heat
9:25
High Heat Capacity
13:24
High Heat of Evaporation
16:42
Water as a Solvent
21:13
Solution
21:28
Solvent
21:48
Example: Water as a Solvent
22:22
Acids and Bases
25:40
Example
25:41
pH
36:30
pH Scale: Acidic, Neutral, and Basic
36:35
Example 1: Molecular Structure and Properties of Water
41:18
Example 2: Special Properties of Water
42:53
Example 3: pH Scale
44:46
Example 4: Acids and Bases
46:19
Organic Compounds

53m 54s

Intro
0:00
Organic Compounds
0:09
Organic Compounds
0:11
Inorganic Compounds
0:15
Examples: Organic Compounds
1:15
Isomers
5:52
Isomers
5:55
Structural Isomers
6:23
Geometric Isomers
8:14
Enantiomers
9:55
Functional Groups
12:46
Examples: Functional Groups
12:59
Amino Group
13:51
Carboxyl Group
14:38
Hydroxyl Group
15:22
Methyl Group
16:14
Carbonyl Group
16:30
Phosphate Group
17:51
Carbohydrates
18:26
Carbohydrates
19:07
Example: Monosaccharides
21:12
Carbohydrates, cont.
24:11
Disaccharides, Polysaccharides and Examples
24:21
Lipids
35:52
Examples of Lipids
36:04
Saturated and Unsaturated
38:57
Phospholipids
43:26
Phospholipids
43:29
Example
43:34
Steroids
46:24
Cholesterol
46:28
Example 1: Isomers
48:11
Example 2: Functional Groups
50:45
Example 3: Galactose, Ketose, and Aldehyde Sugar
52:24
Example 4: Class of Molecules
53:06
Nucleic Acids and Proteins

37m 23s

Intro
0:00
Nucleic Acids
0:09
Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA)
0:29
Nucleic Acids, cont.
2:56
Purines
3:10
Pyrimidines
3:32
Double Helix
4:59
Double Helix and Example
5:01
Proteins
12:33
Amino Acids and Polypeptides
12:39
Examples: Amino Acid
13:25
Polypeptide Formation
18:09
Peptide Bonds
18:14
Primary Structure
18:35
Protein Structure
23:19
Secondary Structure
23:22
Alpha Helices and Beta Pleated Sheets
23:34
Protein Structure
25:43
Tertiary Structure
25:44
5 Types of Interaction
26:56
Example 1: Complementary DNA Strand
31:45
Example 2: Differences Between DNA and RNA
33:19
Example 3: Amino Acids
34:32
Example 4: Tertiary Structure of Protein
35:46
Section 2: Cell Structure and Function
Cell Types (Prokaryotic and Eukaryotic)

45m 50s

Intro
0:00
Cell Theory and Cell Types
0:12
Cell Theory
0:13
Prokaryotic and Eukaryotic Cells
0:36
Endosymbiotic Theory
1:13
Study of Cells
4:07
Tools and Techniques
4:08
Light Microscopes
5:08
Light vs. Electron Microscopes: Magnification
5:18
Light vs. Electron Microscopes: Resolution
6:26
Light vs. Electron Microscopes: Specimens
7:53
Electron Microscopes: Transmission and Scanning
8:28
Cell Fractionation
10:01
Cell Fractionation Step 1: Homogenization
10:33
Cell Fractionation Step 2: Spin
11:24
Cell Fractionation Step 3: Differential Centrifugation
11:53
Comparison of Prokaryotic and Eukaryotic Cells
14:12
Prokaryotic vs. Eukaryotic Cells: Domains
14:43
Prokaryotic vs. Eukaryotic Cells: Plasma Membrane
15:40
Prokaryotic vs. Eukaryotic Cells: Cell Walls
16:15
Prokaryotic vs. Eukaryotic Cells: Genetic Materials
16:38
Prokaryotic vs. Eukaryotic Cells: Structures
17:28
Prokaryotic vs. Eukaryotic Cells: Unicellular and Multicellular
18:19
Prokaryotic vs. Eukaryotic Cells: Size
18:31
Plasmids
18:52
Prokaryotic vs. Eukaryotic Cells
19:22
Nucleus
19:24
Organelles
19:48
Cytoskeleton
20:02
Cell Wall
20:35
Ribosomes
20:57
Size
21:37
Comparison of Plant and Animal Cells
22:15
Plasma Membrane
22:55
Plant Cells Only: Cell Walls
23:12
Plant Cells Only: Central Vacuole
25:08
Animal Cells Only: Centrioles
26:40
Animal Cells Only: Lysosomes
27:43
Plant vs. Animal Cells
29:16
Overview of Plant and Animal Cells
29:17
Evidence for the Endosymbiotic Theory
30:52
Characteristics of Mitochondria and Chloroplasts
30:54
Example 1: Prokaryotic vs. Eukaryotic Cells
35:44
Example 2: Endosymbiotic Theory and Evidence
38:38
Example 3: Plant and Animal Cells
41:49
Example 4: Cell Fractionation
43:44
Subcellular Structure

59m 38s

Intro
0:00
Prokaryotic Cells
0:09
Shapes of Prokaryotic Cells
0:22
Cell Wall
1:19
Capsule
3:23
Pili/Fimbria
3:54
Flagella
4:35
Nucleoid
6:16
Plasmid
6:37
Ribosomes
7:09
Eukaryotic Cells (Animal Cell Structure)
8:01
Plasma Membrane
8:13
Microvilli
8:48
Nucleus
9:47
Nucleolus
11:06
Ribosomes: Free and Bound
12:26
Rough Endoplasmic Reticulum (RER)
13:43
Eukaryotic Cells (Animal Cell Structure), cont.
14:51
Endoplasmic Reticulum: Smooth and Rough
15:08
Golgi Apparatus
17:55
Vacuole
20:43
Lysosome
22:01
Mitochondria
25:40
Peroxisomes
28:18
Cytoskeleton
30:41
Cytoplasm and Cytosol
30:53
Microtubules: Centrioles, Spindel Fibers, Clagell, Cillia
32:06
Microfilaments
36:39
Intermediate Filaments and Kerotin
38:52
Eukaryotic Cells (Plant Cell Structure)
40:08
Plasma Membrane, Primary Cell Wall, and Secondary Cell Wall
40:30
Middle Lamella
43:21
Central Cauole
44:12
Plastids: Leucoplasts, Chromoplasts, Chrloroplasts
45:35
Chloroplasts
47:06
Example 1: Structures and Functions
48:46
Example 2: Cell Walls
51:19
Example 3: Cytoskeleton
52:53
Example 4: Antibiotics and the Endosymbiosis Theory
56:55
Cell Membranes and Transport

53m 10s

Intro
0:00
Cell Membrane Structure
0:09
Phospholipids Bilayer
0:11
Chemical Structure: Amphipathic and Fatty Acids
0:25
Cell Membrane Proteins
2:44
Fluid Mosaic Model
2:45
Peripheral Proteins and Integral Proteins
3:19
Transmembrane Proteins
4:34
Cholesterol
4:48
Functions of Membrane Proteins
6:39
Transport Across Cell Membranes
9:52
Transport Across Cell Membranes
9:53
Methods of Passive Transport
12:07
Passive and Active Transport
12:08
Simple Diffusion
12:45
Facilitated Diffusion
15:20
Osmosis
17:17
Definition and Example of Osmosis
17:18
Hypertonic, Hypotonic, and Isotonic
21:47
Active Transport
27:57
Active Transport
28:17
Sodium and Potassium Pump
29:45
Cotransport
34:38
2 Types of Active Transport
37:09
Endocytosis and Exocytosis
37:38
Endocytosis and Exocytosis
37:51
Types of Endocytosis: Pinocytosis
40:39
Types of Endocytosis: Phagocytosis
41:02
Receptor Mediated Endocytosis
41:27
Receptor Mediated Endocytosis
41:28
Example 1: Cell Membrane and Permeable Substances
43:59
Example 2: Osmosis
45:20
Example 3: Active Transport, Cotransport, Simple and Facilitated Diffusion
47:36
Example 4: Match Terms with Definition
50:55
Cellular Communication

57m 9s

Intro
0:00
Extracellular Matrix
0:28
The Extracellular Matrix (ECM)
0:29
ECM in Animal Cells
0:55
Fibronectin and Integrins
1:34
Intercellular Communication in Plants
2:48
Intercellular Communication in Plants: Plasmodesmata
2:50
Cell to Cell Communication in Animal Cells
3:39
Cell Junctions
3:42
Desmosomes
3:54
Tight Junctions
5:07
Gap Junctions
7:00
Cell Signaling
8:17
Cell Signaling: Ligand and Signal Transduction Pathway
8:18
Direct Contact
8:48
Over Distances Contact and Hormones
10:09
Stages of Cell Signaling
11:53
Reception Phase
11:54
Transduction Phase
13:49
Response Phase
14:45
Cell Membrane Receptors
15:37
G-Protein Coupled Receptor
15:38
Cell Membrane Receptor, Cont.
21:37
Receptor Tyrosine Kinases (RTKs)
21:38
Autophosphorylation, Monomer, and Dimer
22:57
Cell Membrane Receptor, Cont.
27:01
Ligand-Gated Ion Channels
27:02
Intracellular Receptors
29:43
Intracellular Receptor and Receptor -Ligand Complex
29:44
Signal Transduction
32:57
Signal Transduction Pathways
32:58
Adenylyl Cyclase and cAMP
35:53
Second Messengers
39:18
cGMP, Inositol Trisphosphate, and Diacylglycerol
39:20
Cell Response
45:15
Cell Response
45:16
Apoptosis
46:57
Example 1: Tight Junction and Gap Junction
48:29
Example 2: Three Phases of Cell Signaling
51:48
Example 3: Ligands and Binding of Hormone
54:03
Example 4: Signal Transduction
56:06
Section 3: Cell Division
The Cell Cycle

37m 49s

Intro
0:00
Functions of Cell Division
0:09
Overview of Cell Division: Reproduction, Growth, and Repair
0:11
Important Term: Daughter Cells
2:25
Chromosome Structure
3:36
Chromosome Structure: Sister Chromatids and Centromere
3:37
Chromosome Structure: Chromatin
4:31
Chromosome with One Chromatid or Two Chromatids
5:25
Chromosome Structure: Long and Short Arm
6:49
Mitosis and Meiosis
7:00
Mitosis
7:41
Meiosis
8:40
The Cell Cycle
10:43
Mitotic Phase and Interphase
10:44
Cytokinesis
15:51
Cytokinesis in Animal Cell: Cleavage Furrow
15:52
Cytokinesis in Plant Cell: Cell Plate
17:28
Control of the Cell Cycle
18:28
Cell Cycle Control System and Checkpoints
18:29
Cyclins and Cyclin Dependent Kinases
21:18
Cyclins and Cyclin Dependent Kinases (CDKSs)
21:20
MPF
23:17
Internal Factor Regulating Cell Cycle
24:00
External Factor Regulating Cell Cycle
24:53
Contact Inhibition and Anchorage Dependent
25:53
Cancer and the Cell Cycle
27:42
Cancer Cells
27:46
Example1: Parts of the Chromosome
30:15
Example 2: Cell Cycle
31:50
Example 3: Control of the Cell Cycle
33:32
Example 4: Cancer and the Cell
35:01
Mitosis

35m 1s

Intro
0:00
Review of the Cell Cycle
0:09
Interphase: G1 Phase
0:34
Interphase: S Phase
0:56
Interphase: G2 Phase
1:31
M Phase: Mitosis and Cytokinesis
1:47
Overview of Mitosis
3:08
What is Mitosis?
3:10
Overview of Mitosis
3:17
Diploid and Haploid
5:37
Homologous Chromosomes
6:04
The Spindle Apparatus
11:57
The Spindle Apparatus
12:00
Centrosomes and Centrioles
12:40
Microtubule Organizing Center
13:03
Spindle Fiber of Spindle Microtubules
13:23
Kinetochores
14:06
Asters
15:45
Prophase
16:47
First Phase of Mitosis: Prophase
16:54
Metaphase
20:05
Second Phase of Mitosis: Metaphase
20:10
Anaphase
22:52
Third Phase of Mitosis: Anaphase
22:53
Telophase and Cytokinesis
24:34
Last Phase of Mitosis: Telophase and Cytokinesis
24:35
Summary of Mitosis
27:46
Summary of Mitosis
27:47
Example 1: Spindle Apparatus
28:50
Example 2: Last Phase of Mitosis
30:39
Example 3: Prophase
32:41
Example 4: Identify the Phase
33:52
Meiosis

1h 58s

Intro
0:00
Haploid and Diploid Cells
0:09
Diploid and Somatic Cells
0:29
Haploid and Gametes
1:20
Example: Human Cells and Chromosomes
1:41
Sex Chromosomes
6:00
Comparison of Mitosis and Meiosis
10:42
Mitosis Vs. Meiosis: Cell Division
10:59
Mitosis Vs. Meiosis: Daughter Cells
12:31
Meiosis: Pairing of Homologous Chromosomes
13:40
Mitosis and Meiosis
14:21
Process of Mitosis
14:27
Process of Meiosis
16:12
Synapsis and Crossing Over
19:14
Prophase I: Synapsis and Crossing Over
19:15
Chiasmata
22:33
Meiosis I
25:49
Prophase I: Crossing Over
25:50
Metaphase I: Homologs Line Up
26:00
Anaphase I: Homologs Separate
28:16
Telophase I and Cytokinesis
29:15
Independent Assortment
30:58
Meiosis II
32:17
Propphase II
33:50
Metaphase II
34:06
Anaphase II
34:50
Telophase II
36:09
Cytokinesis
37:00
Summary of Meiosis
38:15
Summary of Meiosis
38:16
Cell Division Mechanism in Plants
41:57
Example 1: Cell Division and Meiosis
46:15
Example 2: Phases of Meiosis
50:22
Example 3: Label the Figure
54:29
Example 4: Four Differences Between Mitosis and Meiosis
56:37
Section 4: Cellular Energetics
Enzymes

51m 3s

Intro
0:00
Law of Thermodynamics
0:08
Thermodynamics
0:09
The First Law of Thermodynamics
0:37
The Second Law of Thermodynamics
1:24
Entropy
1:35
The Gibbs Free Energy Equation
3:07
The Gibbs Free Energy Equation
3:08
ATP
8:23
Adenosine Triphosphate (ATP)
8:24
Cellular Respiration
11:32
Catabolic Pathways
12:28
Anabolic Pathways
12:54
Enzymes
14:31
Enzymes
14:32
Enzymes and Exergonic Reaction
14:40
Enzymes and Endergonic Reaction
16:36
Enzyme Specificity
21:29
Substrate
21:41
Induced Fit
23:04
Factors Affecting Enzyme Activity
25:55
Substrate Concentration
26:07
pH
27:10
Temperature
29:14
Presence of Cofactors
29:57
Regulation of Enzyme Activity
31:12
Competitive Inhibitors
32:13
Noncompetitive Inhibitors
33:52
Feedback Inhibition
35:22
Allosteric Interactions
36:56
Allosteric Regulators
37:00
Example 1: Is the Inhibitor Competitive or Noncompetitive?
40:49
Example 2: Thermophiles
44:18
Example 3: Exergonic or Endergonic
46:09
Example 4: Energy Vs. Reaction Progress Graph
48:47
Glycolysis and Anaerobic Respiration

38m 1s

Intro
0:00
Cellular Respiration Overview
0:13
Cellular Respiration
0:14
Anaerobic Respiration vs. Aerobic Respiration
3:50
Glycolysis Overview
4:48
Overview of Glycolysis
4:50
Glycolysis Involves a Redox Reaction
7:02
Redox Reaction
7:04
Glycolysis
15:04
Important Facts About Glycolysis
15:07
Energy Invested Phase
16:12
Splitting of Fructose 1,6-Phosphate and Energy Payoff Phase
17:50
Substrate Level Phophorylation
22:12
Aerobic Versus Anaerobic Respiration
23:57
Aerobic Versus Anaerobic Respiration
23:58
Cellular Respiration Overview
27:15
When Cellular Respiration is Anaerobic
27:17
Glycolysis
28:26
Alcohol Fermentation
28:45
Lactic Acid Fermentation
29:58
Example 1: Glycolysis
31:04
Example 2: Glycolysis, Fermentation and Anaerobic Respiration
33:44
Example 3: Aerobic Respiration Vs. Anaerobic Respiration
35:25
Example 4: Exergonic Reaction and Endergonic Reaction
36:42
Aerobic Respiration

51m 6s

Intro
0:00
Aerobic Vs. Anaerobic Respiration
0:06
Aerobic and Anaerobic Comparison
0:07
Review of Glycolysis
1:48
Overview of Glycolysis
2:06
Glycolysis: Energy Investment Phase
2:25
Glycolysis: Energy Payoff Phase
2:58
Conversion of Pyruvate to Acetyl CoA
4:55
Conversion of Pyruvate to Acetyl CoA
4:56
Energy Formation
8:06
Mitochondrial Structure
8:58
Endosymbiosis Theory
9:23
Matrix
10:00
Outer Membrane, Inner Membrane, and Intermembrane Space
10:43
Cristae
11:47
The Citric Acid Cycle
12:11
The Citric Acid Cycle (Also Called Krebs Cycle)
12:12
Substrate Level Phosphorylation
18:47
Summary of ATP, NADH, and FADH2 Production
23:13
Process: Glycolysis
23:28
Process: Acetyl CoA Production
23:36
Process: Citric Acid Cycle
23:52
The Electron Transport Chain
24:24
Oxidative Phosphorylation
24:28
The Electron Transport Chain and ATP Synthase
25:20
Carrier Molecules: Cytochromes
27:18
Carrier Molecules: Flavin Mononucleotide (FMN)
28:05
Chemiosmosis
32:46
The Process of Chemiosmosis
32:47
Summary of ATP Produced by Aerobic Respiration
38:24
ATP Produced by Aerobic Respiration
38:27
Example 1: Aerobic Respiration
43:38
Example 2: Label the Location for Each Process and Structure
45:08
Example 3: The Electron Transport Chain
47:06
Example 4: Mitochondrial Inner Membrane
48:38
Photosynthesis

1h 2m 52s

Intro
0:00
Photosynthesis
0:09
Introduction to Photosynthesis
0:10
Autotrophs and Heterotrophs
0:25
Overview of Photosynthesis Reaction
1:05
Leaf Anatomy and Chloroplast Structure
2:54
Chloroplast
2:55
Cuticle
3:16
Upper Epidermis
3:27
Mesophyll
3:40
Stomates
4:00
Guard Cells
4:45
Transpiration
5:01
Vascular Bundle
5:20
Stroma and Double Membrane
6:20
Grana
7:17
Thylakoids
7:30
Dark Reaction and Light Reaction
7:46
Light Reactions
8:43
Light Reactions
8:47
Pigments: Chlorophyll a, Chlorophyll b, and Carotenoids
9:19
Wave and Particle
12:10
Photon
12:34
Photosystems
13:24
Photosystems
13:28
Reaction-Center Complex and Light Harvesting Complexes
14:01
Noncyclic Photophosphorylation
17:46
Noncyclic Photophosphorylation Overview
17:47
What is Photophosphorylation?
18:25
Noncyclic Photophosphorylation Process
19:07
Photolysis and The Rest of Noncyclic Photophosphorylation
21:33
Cyclic Photophosphorylation
31:45
Cyclic Photophosphorylation
31:46
Light Independent Reactions
34:34
The Calvin Cycle
34:35
C3 Plants and Photorespiration
40:31
C3 Plants and Photorespiration
40:32
C4 Plants
45:32
C4 Plants: Structures and Functions
45:33
CAM Plants
50:25
CAM Plants: Structures and Functions
50:35
Example 1: Calvin Cycle
54:34
Example 2: C4 Plant
55:48
Example 3: Photosynthesis and Photorespiration
58:35
Example 4: CAM Plants
1:00:41
Section 5: Molecular Genetics
DNA Synthesis

38m 45s

Intro
0:00
Review of DNA Structure
0:09
DNA Molecules
0:10
Nitrogenous Base: Pyrimidines and Purines
1:25
DNA Double Helix
3:03
Complementary Strands of DNA
3:12
5' to 3' & Antiparallel
4:55
Overview of DNA Replication
7:10
DNA Replication & Semiconservative
7:11
DNA Replication
10:26
Origin of Replication
10:28
Helicase
11:10
Single-Strand Binding Protein
12:05
Topoisomerases
13:14
DNA Polymerase
14:26
Primase
15:55
Leading and Lagging Strands
16:51
Leading Strand and Lagging Strand
16:52
Okazaki Fragments
18:10
DNA Polymerase I
20:11
Ligase
21:12
Proofreading and Mismatch Repair
22:18
Proofreading
22:19
Mismatch
23:33
Telomeres
24:58
Telomeres
24:59
Example 1: Function of Enzymes During DNA Synthesis
28:09
Example 2: Accuracy of the DNA Sequence
31:42
Example 3: Leading Strand and Lagging Strand
32:38
Example 4: Telomeres
35:40
Transcription and Translation

1h 17m 1s

Intro
0:00
Transcription and Translation Overview
0:07
From DNA to RNA to Protein
0:09
Structure and Types of RNA
3:14
Structure and Types of RNA
3:33
mRNA
6:19
rRNA
7:02
tRNA
7:28
Transcription
7:54
Initiation Phase
8:11
Elongation Phase
12:12
Termination Phase
14:51
RNA Processing
16:11
Types of RNA Processing
16:12
Exons and Introns
16:35
Splicing & Spliceosomes
18:27
Addition of a 5' Cap and a Poly A tail
20:41
Alternative Splicing
21:43
Translation
23:41
Nucleotide Triplets or Codons
23:42
Start Codon
25:24
Stop Codons
25:38
Coding of Amino Acids and Wobble Position
25:57
Translation Cont.
28:29
Transfer RNA (tRNA): Structures and Functions
28:30
Ribosomes
35:15
Peptidyl, Aminoacyl, and Exit Site
35:23
Steps of Translation
36:58
Initiation Phase
37:12
Elongation Phase
43:12
Termination Phase
45:28
Mutations
49:43
Types of Mutations
49:44
Substitutions: Silent
51:11
Substitutions: Missense
55:27
Substitutions: Nonsense
59:37
Insertions and Deletions
1:01:10
Example 1: Three Types of Processing that are Performed on pre-mRNA
1:06:53
Example 2: The Process of Translation
1:09:10
Example 3: Transcription
1:12:04
Example 4: Three Types of Substitution Mutations
1:14:09
Viral Structure and Genetics

43m 12s

Intro
0:00
Structure of Viruses
0:09
Structure of Viruses: Capsid and Envelope
0:10
Bacteriophage
1:48
Other Viruses
2:28
Overview of Viral Reproduction
3:15
Host Range
3:48
Step 1: Bind to Host Cell
4:39
Step 2: Viral Nuclei Acids Enter the Cell
5:15
Step 3: Viral Nucleic Acids & Proteins are Synthesized
5:54
Step 4: Virus Assembles
6:34
Step 5: Virus Exits the Cell
6:55
The Lytic Cycle
7:37
Steps in the Lytic Cycle
7:38
The Lysogenic Cycle
11:27
Temperate Phage
11:34
Steps in the Lysogenic Cycle
12:09
RNA Viruses
16:57
Types of RNA Viruses
17:15
Positive Sense
18:16
Negative Sense
18:48
Reproductive Cycle of RNA Viruses
19:32
Retroviruses
25:48
Complementary DNA (cDNA) & Reverse Transcriptase
25:49
Life Cycle of a Retrovirus
28:22
Prions
32:42
Prions: Definition and Examples
32:45
Viroids
34:46
Example 1: The Lytic Cycle
35:37
Example 2: Retrovirus
38:03
Example 3: Positive Sense RNA vs. Negative Sense RNA
39:10
Example 4: The Lysogenic Cycle
40:42
Bacterial Genetics and Gene Regulation

49m 45s

Intro
0:00
Bacterial Genomes
0:09
Structure of Bacterial Genomes
0:16
Transformation
1:22
Transformation
1:23
Vector
2:49
Transduction
3:32
Process of Transduction
3:38
Conjugation
8:06
Conjugation & F factor
8:07
Operons
14:02
Definition and Example of Operon
14:52
Structural Genes
16:23
Promoter Region
17:04
Regulatory Protein & Operators
17:53
The lac Operon
20:09
The lac Operon: Inducible System
20:10
The trp Operon
28:02
The trp Operon: Repressible System
28:03
Corepressor
31:37
Anabolic & Catabolic
33:12
Positive Regulation of the lac Operon
34:39
Positive Regulation of the lac Operon
34:40
Example 1: The Process of Transformation
39:07
Example 2: Operon & Terms
43:29
Example 3: Inducible lac Operon and Repressible trp Operon
45:15
Example 4: lac Operon
47:10
Eukaryotic Gene Regulation and Mobile Genetic Elements

54m 26s

Intro
0:00
Mechanism of Gene Regulation
0:11
Differential Gene Expression
0:13
Levels of Regulation
2:24
Chromatin Structure and Modification
4:35
Chromatin Structure
4:36
Levels of Packing
5:50
Euchromatin and Heterochromatin
8:58
Modification of Chromatin Structure
9:58
Epigenetic
12:49
Regulation of Transcription
14:20
Promoter Region, Exon, and Intron
14:26
Enhancers: Control Element
15:31
Enhancer & DNA-Bending Protein
17:25
Coordinate Control
21:23
Silencers
23:01
Post-Transcriptional Regulation
24:05
Post-Transcriptional Regulation
24:07
Alternative Splicing
27:19
Differences in mRNA Stability
28:02
Non-Coding RNA Molecules: micro RNA & siRNA
30:01
Regulation of Translation and Post-Translational Modifications
32:31
Regulation of Translation and Post-Translational Modifications
32:55
Ubiquitin
35:21
Proteosomes
36:04
Transposons
37:50
Mobile Genetic Elements
37:56
Barbara McClintock
38:37
Transposons & Retrotransposons
40:38
Insertion Sequences
43:14
Complex Transposons
43:58
Example 1: Four Mechanisms that Decrease Production of Protein
45:13
Example 2: Enhancers and Gene Expression
49:09
Example 3: Primary Transcript
50:41
Example 4: Retroviruses and Retrotransposons
52:11
Biotechnology

49m 26s

Intro
0:00
Definition of Biotechnology
0:08
Biotechnology
0:09
Genetic Engineering
1:05
Example: Golden Corn
1:57
Recombinant DNA
2:41
Recombinant DNA
2:42
Transformation
3:24
Transduction
4:24
Restriction Enzymes, Restriction Sites, & DNA Ligase
5:32
Gene Cloning
13:48
Plasmids
14:20
Gene Cloning: Step 1
17:35
Gene Cloning: Step 2
17:57
Gene Cloning: Step 3
18:53
Gene Cloning: Step 4
19:46
Gel Electrophoresis
27:25
What is Gel Electrophoresis?
27:26
Gel Electrophoresis: Step 1
28:13
Gel Electrophoresis: Step 2
28:24
Gel Electrophoresis: Step 3 & 4
28:39
Gel Electrophoresis: Step 5
29:55
Southern Blotting
31:25
Polymerase Chain Reaction (PCR)
32:11
Polymerase Chain Reaction (PCR)
32:12
Denaturing Phase
35:40
Annealing Phase
36:07
Elongation/ Extension Phase
37:06
DNA Sequencing and the Human Genome Project
39:19
DNA Sequencing and the Human Genome Project
39:20
Example 1: Gene Cloning
40:40
Example 2: Recombinant DNA
43:04
Example 3: Match Terms With Descriptions
45:43
Example 4: Polymerase Chain Reaction
47:36
Section 6: Heredity
Mendelian Genetics

1h 32m 8s

Intro
0:00
Background
0:40
Gregory Mendel & Mendel's Law
0:41
Blending Hypothesis
1:04
Particulate Inheritance
2:08
Terminology
2:55
Gene
3:05
Locus
3:57
Allele
4:37
Dominant Allele
5:48
Recessive Allele
7:38
Genotype
9:22
Phenotype
10:01
Homozygous
10:44
Heterozygous
11:39
Penetrance
11:57
Expressivity
14:15
Mendel's Experiments
15:31
Mendel's Experiments: Pea Plants
15:32
The Law of Segregation
21:16
Mendel's Conclusions
21:17
The Law of Segregation
22:57
Punnett Squares
28:27
Using Punnet Squares
28:30
The Law of Independent Assortment
32:35
Monohybrid
32:38
Dihybrid
33:29
The Law of Independent Assortment
34:00
The Law of Independent Assortment, cont.
38:13
The Law of Independent Assortment: Punnet Squares
38:29
Meiosis and Mendel's Laws
43:38
Meiosis and Mendel's Laws
43:39
Test Crosses
49:07
Test Crosses Example
49:08
Probability: Multiplication Rule and the Addition Rule
53:39
Probability Overview
53:40
Independent Events & Multiplication Rule
55:40
Mutually Exclusive Events & Addition Rule
1:00:25
Incomplete Dominance, Codominance and Multiple Alleles
1:02:55
Incomplete Dominance
1:02:56
Incomplete Dominance, Codominance and Multiple Alleles
1:07:06
Codominance and Multiple Alleles
1:07:08
Polygenic Inheritance and Pleoitropy
1:10:19
Polygenic Inheritance and Pleoitropy
1:10:26
Epistasis
1:12:51
Example of Epistasis
1:12:52
Example 1: Genetic of Eye Color and Height
1:17:39
Example 2: Blood Type
1:21:57
Example 3: Pea Plants
1:25:09
Example 4: Coat Color
1:28:34
Linked Genes and Non-Mendelian Modes of Inheritance

39m 38s

Intro
0:00
Review of the Law of Independent Assortment
0:14
Review of the Law of Independent Assortment
0:24
Linked Genes
6:06
Linked Genes
6:07
Bateson & Pannett: Pea Plants
8:00
Crossing Over and Recombination
15:17
Crossing Over and Recombination
15:18
Extranuclear Genes
20:50
Extranuclear Genes
20:51
Cytoplasmic Genes
21:31
Genomic Imprinting
23:45
Genomic Imprinting
23:58
Methylation
24:43
Example 1: Recombination Frequencies & Linkage Map
27:07
Example 2: Linked Genes
28:39
Example 3: Match Terms to Correct Descriptions
36:46
Example 4: Leber's Optic Neuropathy
38:40
Sex-Linked Traits and Pedigree Analysis

43m 39s

Intro
0:00
Sex-Linked Traits
0:09
Human Chromosomes, XY, and XX
0:10
Thomas Morgan's Drosophila
1:44
X-Inactivation and Barr Bodies
14:48
X-Inactivation Overview
14:49
Calico Cats Example
17:04
Pedigrees
19:24
Definition and Example of Pedigree
19:25
Autosomal Dominant Inheritance
20:51
Example: Huntington's Disease
20:52
Autosomal Recessive Inheritance
23:04
Example: Cystic Fibrosis, Tay-Sachs Disease, and Phenylketonuria
23:05
X-Linked Recessive Inheritance
27:06
Example: Hemophilia, Duchene Muscular Dystrohpy, and Color Blindess
27:07
Example 1: Colorblind
29:48
Example 2: Pedigree
37:07
Example 3: Inheritance Pattern
39:54
Example 4: X-inactivation
41:17
Section 7: Evolution
Natural Selection

1h 3m 28s

Intro
0:00
Background
0:09
Work of Other Scientists
0:15
Aristotle
0:43
Carl Linnaeus
1:32
George Cuvier
2:47
James Hutton
4:10
Thomas Malthus
5:05
Jean-Baptiste Lamark
5:45
Darwin's Theory of Natural Selection
7:50
Evolution
8:00
Natural Selection
8:43
Charles Darwin & The Galapagos Islands
10:20
Genetic Variation
20:37
Mutations
20:38
Independent Assortment
21:04
Crossing Over
24:40
Random Fertilization
25:26
Natural Selection and the Peppered Moth
26:37
Natural Selection and the Peppered Moth
26:38
Types of Natural Selection
29:52
Directional Selection
29:55
Stabilizing Selection
32:43
Disruptive Selection
34:21
Sexual Selection
36:18
Sexual Dimorphism
37:30
Intersexual Selection
37:57
Intrasexual Selection
39:20
Evidence for Evolution
40:55
Paleontology: Fossil Record
41:30
Biogeography
45:35
Continental Drift
46:06
Pangaea
46:28
Marsupials
47:11
Homologous and Analogous Structure
50:10
Homologous Structure
50:12
Analogous Structure
53:21
Example 1: Genetic Variation & Natural Selection
56:15
Example 2: Types of Natural Selection
58:07
Example 3: Mechanisms By Which Genetic Variation is Maintained Within a Population
1:00:12
Example 4: Difference Between Homologous and Analogous Structures
1:01:28
Population Genetic and Evolution

53m 22s

Intro
0:00
Review of Natural Selection
0:12
Review of Natural Selection
0:13
Genetic Drift and Gene Flow
4:40
Definition of Genetic Drift
4:41
Example of Genetic Drift: Cholera Epidemic
5:15
Genetic Drift: Founder Effect
7:28
Genetic Drift: Bottleneck Effect
10:27
Gene Flow
13:00
Quantifying Genetic Variation
14:32
Average Heterozygosity
15:08
Nucleotide Variation
17:05
Maintaining Genetic Variation
18:12
Heterozygote Advantage
19:45
Example of Heterozygote Advantage: Sickle Cell Anemia
20:21
Diploidy
23:44
Geographic Variation
26:54
Frequency Dependent Selection and Outbreeding
28:15
Neutral Traits
30:55
The Hardy-Weinberg Equilibrium
31:11
The Hardy-Weinberg Equilibrium
31:49
The Hardy-Weinberg Conditions
32:42
The Hardy-Weinberg Equation
34:05
The Hardy-Weinberg Example
36:33
Example 1: Match Terms to Descriptions
42:28
Example 2: The Hardy-Weinberg Equilibrium
44:31
Example 3: The Hardy-Weinberg Equilibrium
49:10
Example 4: Maintaining Genetic Variation
51:30
Speciation and Patterns of Evolution

51m 2s

Intro
0:00
Early Life on Earth
0:08
Early Earth
0:09
1920's Oparin & Haldane
0:58
Abiogenesis
2:15
1950's Miller & Urey
2:45
Ribozymes
5:34
3.5 Billion Years Ago
6:39
2.5 Billion Years Ago
7:14
1.5 Billion Years Ago
7:41
Endosymbiosis
8:00
540 Million Years Ago: Cambrian Explosion
9:57
Gradualism and Punctuated Equilibrium
11:46
Gradualism
11:47
Punctuated Equilibrium
12:45
Adaptive Radiation
15:08
Adaptive Radiation
15:09
Example of Adaptive Radiation: Galapogos Islands
17:11
Convergent Evolution, Divergent Evolution, and Coevolution
18:30
Convergent Evolution
18:39
Divergent Evolution
21:30
Coevolution
23:49
Speciation
26:27
Definition and Example of Species
26:29
Reproductive Isolation: Prezygotive
27:49
Reproductive Isolation: Post zygotic
29:28
Allopatric Speciation
30:21
Allopatric Speciation & Geographic Isolation
30:28
Genetic Drift
31:31
Sympatric Speciation
34:10
Sympatric Speciation
34:11
Polyploidy & Autopolyploidy
35:12
Habitat Isolation
39:17
Temporal Isolation
41:27
Selection Selection
41:40
Example 1: Pattern of Evolution
42:53
Example 2: Sympatric Speciation
45:16
Example 3: Patterns of Evolution
48:08
Example 4: Patterns of Evolution
49:27
Section 8: Diversity of Life
Classification

1h 51s

Intro
0:00
Systems of Classification
0:07
Taxonomy
0:08
Phylogeny
1:04
Phylogenetics Tree
1:44
Cladistics
3:37
Classification of Organisms
5:31
Example of Carl Linnaeus System
5:32
Domains
9:26
Kingdoms: Monera, Protista, Plantae, Fungi, Animalia
9:27
Monera
10:06
Phylogentics Tree: Eurkarya, Bacteria, Archaea
11:58
Domain Eukarya
12:50
Domain Bacteria
15:43
Domain Bacteria
15:46
Pathogens
16:41
Decomposers
18:00
Domain Archaea
19:43
Extremophiles Archaea: Thermophiles and Halophiles
19:44
Methanogens
20:58
Phototrophs, Autotrophs, Chemotrophs and Heterotrophs
24:40
Phototrophs and Chemotrophs
25:02
Autotrophs and Heterotrophs
26:54
Photoautotrophs
28:50
Photoheterotrophs
29:28
Chemoautotrophs
30:06
Chemoheterotrophs
31:37
Domain Eukarya
32:40
Domain Eukarya
32:43
Plant Kingdom
34:28
Protists
35:48
Fungi Kingdom
37:06
Animal Kingdom
38:35
Body Symmetry
39:25
Lack Symetry
39:40
Radial Symmetry: Sea Aneome
40:15
Bilateral Symmetry
41:55
Cephalization
43:29
Germ Layers
44:54
Diploblastic Animals
45:18
Triploblastic Animals
45:25
Ectoderm
45:36
Endoderm
46:07
Mesoderm
46:41
Coelomates
47:14
Coelom
47:15
Acoelomate
48:22
Pseudocoelomate
48:59
Coelomate
49:31
Protosomes
50:46
Deuterosomes
51:20
Example 1: Domains
53:01
Example 2: Match Terms with Descriptions
56:00
Example 3: Kingdom Monera and Domain Archaea
57:50
Example 4: System of Classification
59:37
Bacteria

36m 46s

Intro
0:00
Comparison of Domain Archaea and Domain Bacteria
0:08
Overview of Archaea and Bacteria
0:09
Archaea vs. Bacteria: Nucleus, Organelles, and Organization of Genetic Material
1:45
Archaea vs. Bacteria: Cell Walls
2:20
Archaea vs. Bacteria: Number of Types of RNA Pol
2:29
Archaea vs. Bacteria: Membrane Lipids
2:53
Archaea vs. Bacteria: Introns
3:33
Bacteria: Pathogen
4:03
Bacteria: Decomposers and Fix Nitrogen
5:18
Bacteria: Aerobic, Anaerobic, Strict Anaerobes & Facultative Anaerobes
6:02
Phototrophs, Autotrophs, Heterotrophs and Chemotrophs
7:14
Phototrophs and Chemotrophs
7:50
Autotrophs and Heterotrophs
8:53
Photoautotrophs and Photoheterotrophs
10:15
Chemoautotroph and Chemoheterotrophs
11:07
Structure of Bacteria
12:21
Shapes: Cocci, Bacilli, Vibrio, and Spirochetes
12:26
Structures: Plasma Membrane and Cell Wall
14:23
Structures: Nucleoid Region, Plasmid, and Capsule Basal Apparatus, and Filament
15:30
Structures: Flagella, Basal Apparatus, Hook, and Filament
16:36
Structures: Pili, Fimbrae and Ribosome
18:00
Peptidoglycan: Gram + and Gram -
18:50
Bacterial Genomes and Reproduction
21:14
Bacterial Genomes
21:21
Reproduction of Bacteria
22:13
Transformation
23:26
Vector
24:34
Competent
25:15
Conjugation
25:53
Conjugation: F+ and R Plasmids
25:55
Example 1: Species
29:41
Example 2: Bacteria and Exchange of Genetic Material
32:31
Example 3: Ways in Which Bacteria are Beneficial to Other Organisms
33:48
Example 4: Domain Bacteria vs. Domain Archaea
34:53
Protists

1h 18m 48s

Intro
0:00
Classification of Protists
0:08
Classification of Protists
0:09
'Plant-like' Protists
2:06
'Animal-like' Protists
3:19
'Fungus-like' Protists
3:57
Serial Endosymbiosis Theory
5:15
Endosymbiosis Theory
5:33
Photosynthetic Protists
7:33
Life Cycles with a Diploid Adult
13:35
Life Cycles with a Diploid Adult
13:56
Life Cycles with a Haploid Adult
15:31
Life Cycles with a Haploid Adult
15:32
Alternation of Generations
17:22
Alternation of Generations: Multicellular Haploid & Diploid Phase
17:23
Plant-Like Protists
19:58
Euglenids
20:43
Dino Flagellates
22:57
Diatoms
26:07
Plant-Like Protists
28:44
Golden Algae
28:45
Brown Algeas
30:05
Plant-Like Protists
33:38
Red Algae
33:39
Green Algae
35:36
Green Algae: Chlamydomonus
37:44
Animal-Like Protists
40:04
Animal-Like Protists Overview
40:05
Sporozoans (Apicomplexans)
40:32
Alveolates
41:41
Sporozoans (Apicomplexans): Plasmodium & Malaria
42:59
Animal-Like Protists
48:44
Kinetoplastids
48:50
Example of Kinetoplastids: Trypanosomes & African Sleeping Sickness
49:30
Ciliate
50:42
Conjugation
53:16
Conjugation
53:26
Animal-Like Protists
57:08
Parabasilids
57:31
Diplomonads
59:06
Rhizopods
1:00:13
Forams
1:02:25
Radiolarians
1:03:28
Fungus-Like Protists
1:04:25
Fungus-Like Protists Overview
1:04:26
Slime Molds
1:05:15
Cellular Slime Molds: Feeding Stage
1:09:21
Oomycetes
1:11:15
Example 1: Alternation of Generations and Sexual Life Cycles
1:13:05
Example 2: Match Protists to Their Descriptions
1:14:12
Example 3: Three Structures that Protists Use for Motility
1:16:22
Example 4: Paramecium
1:17:04
Fungi

35m 24s

Intro
0:00
Introduction to Fungi
0:09
Introduction to Fungi
0:10
Mycologist
0:34
Examples of Fungi
0:45
Hyphae, Mycelia, Chitin, and Coencytic Fungi
2:26
Ancestral Protists
5:00
Role of Fungi in the Environment
5:35
Fungi as Decomposers
5:36
Mycorrrhiza
6:19
Lichen
8:52
Life Cycle of Fungi
11:32
Asexual Reproduction
11:33
Sexual Reproduction & Dikaryotic Cell
13:16
Chytridiomycota
18:12
Phylum Chytridiomycota
18:17
Zoospores
18:50
Zygomycota
19:07
Coenocytic & Zygomycota Life Cycle
19:08
Basidiomycota
24:27
Basidiomycota Overview
24:28
Basidiomycota Life Cycle
26:11
Ascomycota
28:00
Ascomycota Overview
28:01
Ascomycota Reproduction
28:50
Example 1: Fungi Fill in the Blank
31:02
Example 2: Name Two Roles Played by Fungi in the Environment
32:09
Example 3: Difference Between Diploid Cell and Dikaryon Cell
33:42
Example 4: Phylum of Fungi, Flagellated Spore, Coencytic
34:36
Invertebrates

1h 3m 3s

Intro
0:00
Porifera (Sponges)
0:33
Chordata
0:56
Porifera (Sponges): Sessile, Layers, Aceolomates, and Filter Feeders
1:24
Amoebocytes Cell
4:47
Choanocytes Cell
5:56
Sexual Reproduction
6:28
Cnidaria
8:05
Cnidaria Overview
8:06
Polyp & Medusa: Gastrovasular Cavity
8:29
Cnidocytes
9:42
Anthozoa
10:40
Cubozoa
11:23
Hydrozoa
11:53
Scyphoza
13:25
Platyhelminthes (Flatworms)
13:58
Flatworms: Tribloblastic, Bilateral Symmetry, and Cephalization
13:59
GI System
15:33
Excretory System
16:07
Nervous System
17:00
Turbellarians
17:36
Trematodes
18:42
Monageneans
21:32
Cestoda
21:55
Rotifera (Rotifers)
23:45
Rotifers: Digestive Tract, Pseudocoelem, and Stuctures
23:46
Reproduction: Parthenogenesis
25:33
Nematoda (Roundworms)
26:44
Nematoda (Roundworms)
26:45
Parasites: Pinworms & Hookworms
27:26
Annelida
28:36
Annelida Overview
28:37
Open Circulatory
29:21
Closed Circulatory
30:18
Nervous System
31:19
Excretory System
31:43
Oligochaete
32:07
Leeches
33:22
Polychaetes
34:42
Mollusca
35:26
Mollusca Features
35:27
Major Part 1: Visceral Mass
36:21
Major Part 2: Head-foot Region
36:49
Major Part 3: Mantle
37:13
Radula
37:49
Circulatory, Reproductive, Excretory, and Nervous System
38:14
Major Classes of Molluscs
39:12
Gastropoda
39:17
Polyplacophora
40:15
Bivales
40:41
Cephalopods
41:42
Arthropoda
43:35
Arthropoda Overview
43:36
Segmented Bodies
44:14
Exoskeleton
44:52
Jointed Appendages
45:28
Hemolyph, Excretory & Respiratory System
45:41
Myriapoda & Centipedes
47:15
Cheliceriforms
48:20
Crustcea
49:31
Herapoda
50:03
Echinodermata
52:59
Echinodermata
53:00
Watrer Vascular System
54:20
Selected Characteristics of Invertebrates
57:11
Selected Characteristics of Invertebrates
57:12
Example 1: Phylum Description
58:43
Example 2: Complex Animals
59:50
Example 3: Match Organisms to the Correct Phylum
1:01:03
Example 4: Phylum Arthropoda
1:02:01
Vertebrates

1h 7s

Intro
0:00
Phylum Chordata
0:06
Chordates Overview
0:07
Notochord and Dorsal Hollow Nerve Chord
1:24
Pharyngeal Clefts, Arches, and Post-anal Tail
3:41
Invertebrate Chordates
6:48
Lancelets
7:13
Tunicates
8:02
Hagfishes: Craniates
8:55
Vertebrate Chordates
10:41
Veterbrates Overview
10:42
Lampreys
11:00
Gnathostomes
12:20
Six Major Classes of Vertebrates
12:53
chondrichthyes
14:23
Chondrichthyes Overview
14:24
Ectothermic and Endothermic
14:42
Sharks: Lateral Line System, Neuromastsn, and Gills
15:27
Oviparous and Viviparous
17:23
Osteichthyes (Bony Fishes)
18:12
Osteichythes (Bony Fishes) Overview
18:13
Operculum
19:05
Swim Bladder
19:53
Ray-Finned Fishes
20:34
Lobe-Finned Fishes
20:58
Tetrapods
22:36
Tetrapods: Definition and Examples
22:37
Amphibians
23:53
Amphibians Overview
23:54
Order Urodela
25:51
Order Apoda
27:03
Order Anura
27:55
Reptiles
30:19
Reptiles Overview
30:20
Amniotes
30:37
Examples of Reptiles
32:46
Reptiles: Ectotherms, Gas Exchange, and Heart
33:40
Orders of Reptiles
34:17
Sphenodontia, Squamata, Testudines, and Crocodilia
34:21
Birds
36:09
Birds and Dinosaurs
36:18
Theropods
38:00
Birds: High Metabolism, Respiratory System, Lungs, and Heart
39:04
Birds: Endothermic, Bones, and Feathers
40:15
Mammals
42:33
Mammals Overview
42:35
Diaphragm and Heart
42:57
Diphydont
43:44
Synapsids
44:41
Monotremes
46:36
Monotremes
46:37
Marsupials
47:12
Marsupials: Definition and Examples
47:16
Convergent Evolution
48:09
Eutherians (Placental Mammals)
49:42
Placenta
49:43
Order Carnivora
50:48
Order Raodentia
51:00
Order Cetaceans
51:14
Primates
51:41
Primates Overview
51:42
Nails and Hands
51:58
Vision
52:51
Social Care for Young
53:28
Brain
53:43
Example 1: Distinguishing Characteristics of Chordates
54:33
Example 2: Match Description to Correct Term
55:56
Example 3: Bird's Anatomy
57:38
Example 4: Vertebrate Animal, Marine Environment, and Ectothermic
59:14
Section 9: Plants
Seedless Plants

34m 31s

Intro
0:00
Origin and Classification of Plants
0:06
Origin and Classification of Plants
0:07
Non-Vascular vs. Vascular Plants
1:29
Seedless Vascular & Seed Plants
2:28
Angiosperms & Gymnosperms
2:50
Alternation of Generations
3:54
Alternation of Generations
3:55
Bryophytes
7:58
Overview of Bryrophytes
7:59
Example: Moss Gametophyte
9:29
Example: Moss Sporophyte
9:50
Moss Life Cycle
10:12
Moss Life Cycle
10:13
Seedless Vascular Plants
13:23
Vascular Structures: Cell Walls, and Lignin
13:24
Homosporous
17:11
Heterosporous
17:48
Adaptations to Life on land
21:10
Adaptation 1: Cell Walls
21:38
Adaptation 2: Vascular Plants
21:59
Adaptation 3 : Xylem & Phloem
22:31
Adaptation 4: Seeds
23:07
Adaptation 5: Pollen
23:35
Adaptation 6: Stomata
24:45
Adaptation 7: Reduced Gametophyte Generation
25:32
Example 1: Bryophytes
26:39
Example 2: Sporangium, Lignin, Gametophyte, and Antheridium
28:34
Example 3: Adaptations to Life on Land
29:47
Example 4: Life Cycle of Plant
32:06
Plant Structure

1h 1m 21s

Intro
0:00
Plant Tissue
0:05
Dermal Tissue
0:15
Vascular Tissue
0:39
Ground Tissue
1:31
Cell Types in Plants
2:14
Parenchyma Cells
2:24
Collenchyma Cells
3:21
Sclerenchyma Cells
3:59
Xylem
5:04
Xylem: Tracheids and Vessel Elements
6:12
Gymnosperms vs. Angiosperms
7:53
Phloem
8:37
Phloem: Structures and Function
8:38
Sieve-Tube Elements
8:45
Companion Cells & Sieve Plates
9:11
Roots
10:08
Taproots & Fibrous
10:09
Aerial Roots & Prop Roots
11:41
Structures and Functions of Root: Dicot & Monocot
13:00
Pericyle
16:57
The Nitrogen Cylce
18:05
The Nitrogen Cycle
18:06
Mycorrhizae
24:20
Mycorrhizae
24:23
Ectomycorrhiza
26:03
Endomycorrhiza
26:25
Stems
26:53
Stems
26:54
Vascular Bundles of Monocots and Dicots
28:18
Leaves
29:48
Blade & Petiole
30:13
Upper Epidermis, Lower Epidermis & Cuticle
30:39
Ground Tissue, Palisade Mesophyll, Spongy Mesophyll
31:35
Stomata Pores
33:23
Guard Cells
34:15
Vascular Tissues: Vascular Bundles and Bundle Sheath
34:46
Stomata
36:12
Stomata & Gas Exchange
36:16
Guard Cells, Flaccid, and Turgid
36:43
Water Potential
38:03
Factors for Opening Stoma
40:35
Factors Causing Stoma to Close
42:44
Overview of Plant Growth
44:23
Overview of Plant Growth
44:24
Primary Plant Growth
46:19
Apical Meristems
46:25
Root Growth: Zone of Cell Division
46:44
Root Growth: Zone of Cell Elongation
47:35
Root Growth: Zone of Cell Differentiation
47:55
Stem Growth: Leaf Primodia
48:16
Secondary Plant Growth
48:48
Secondary Plant Growth Overview
48:59
Vascular Cambium: Secondary Xylem and Phloem
49:38
Cork Cambium: Periderm and Lenticels
51:10
Example 1: Leaf Structures
53:30
Example 2: List Three Types of Plant Tissue and their Major Functions
55:13
Example 3: What are Two Factors that Stimulate the Opening or Closing of Stomata?
56:58
Example 4: Plant Growth
59:18
Gymnosperms and Angiosperms

1h 1m 51s

Intro
0:00
Seed Plants
0:22
Sporopollenin
0:58
Heterosporous: Megasporangia
2:49
Heterosporous: Microsporangia
3:19
Gymnosperms
5:20
Gymnosperms
5:21
Gymnosperm Life Cycle
7:30
Gymnosperm Life Cycle
7:31
Flower Structure
15:15
Petal & Pollination
15:48
Sepal
16:52
Stamen: Anther, Filament
17:05
Pistill: Stigma, Style, Ovule, Ovary
17:55
Complete Flowers
20:14
Angiosperm Gametophyte Formation
20:47
Male Gametophyte: Microsporocytes, Microsporangia & Meiosis
20:57
Female Gametophyte: Megasporocytes & Meiosis
24:22
Double Fertilization
25:43
Double Fertilization: Pollen Tube and Endosperm
25:44
Angiosperm Life Cycle
29:43
Angiosperm Life Cycle
29:48
Seed Structure and Development
33:37
Seed Structure and Development
33:38
Pollen Dispersal
37:53
Abiotic
38:28
Biotic
39:30
Prevention of Self-Pollination
40:48
Mechanism 1
41:08
Mechanism 2: Dioecious
41:37
Mechanism 3
42:32
Self-Incompatibility
43:08
Gametophytic Self-Incompatibility
44:38
Sporophytic Self-Incompatibility
46:50
Asexual Reproduction
48:33
Asexual Reproduction & Vegetative Propagation
48:34
Graftiry
50:19
Monocots and Dicots
51:34
Monocots vs.Dicots
51:35
Example 1: Double Fertilization
54:43
Example 2: Mechanisms of Self-Fertilization
56:02
Example 3: Monocots vs. Dicots
58:11
Example 4: Flower Structures
1:00:11
Transport of Nutrients and Water in Plants

40m 30s

Intro
0:00
Review of Plant Cell Structure
0:14
Cell Wall, Plasma Membrane, Middle lamella, and Cytoplasm
0:15
Plasmodesmata, Chloroplasts, and Central Vacuole
3:24
Water Absorption by Plants
4:28
Root Hairs and Mycorrhizae
4:30
Osmosis and Water Potential
5:41
Apoplast and Symplast Pathways
10:01
Apoplast and Symplast Pathways
10:02
Xylem Structure
21:02
Tracheids and Vessel Elements
21:03
Bulk Flow
23:00
Transpiration
23:26
Cohesion
25:10
Adhesion
26:10
Phloem Structure
27:25
Pholem
27:26
Sieve-Tube Elements
27:48
Companion Cells
28:17
Translocation
28:42
Sugar Source and Sugar Sink Overview
28:43
Example of Sugar Sink
30:01
Example of Sugar Source
30:48
Example 1: Match the Following Terms to their Description
33:17
Example 2: Water Potential
34:58
Example 3: Bulk Flow
36:56
Example 4: Sugar Sink and Sugar Source
38:33
Plant Hormones and Tropisms

48m 10s

Intro
0:00
Plant Cell Signaling
0:17
Plant Cell Signaling Overview
0:18
Step 1: Reception
1:03
Step 2: Transduction
2:32
Step 3: Response
2:58
Second Messengers
3:52
Protein Kinases
4:42
Auxins
6:14
Auxins
6:18
Indoleacetic Acid (IAA)
7:23
Cytokinins and Gibberellins
11:10
Cytokinins: Apical Dominance & Delay of Aging
11:16
Gibberellins: 'Bolting'
13:51
Ethylene
15:33
Ethylene
15:34
Positive Feedback
15:46
Leaf Abscission
18:05
Mechanical Stress: Triple Response
19:36
Abscisic Acid
21:10
Abscisic Acid
21:15
Tropisms
23:11
Positive Tropism
23:50
Negative Tropism
24:07
Statoliths
26:21
Phytochromes and Photoperiodism
27:48
Phytochromes: PR and PFR
27:56
Circadian Rhythms
32:06
Photoperiod
33:13
Photoperiodism
33:38
Gerner & Allard
34:35
Short-Day Plant
35:22
Long-Day Plant
37:00
Example 1: Plant Hormones
41:28
Example 2: Cytokinins & Gibberellins
43:00
Example 3: Match the Following Terms to their Description
44:46
Example 4: Hormones & Cell Response
46:14
Section 10: Animal Structure and Physiology
The Respiratory System

48m 14s

Intro
0:00
Gas Exchange in Animals
0:17
Respiration
0:19
Ventilation
1:09
Characteristics of Respiratory Surfaces
1:53
Gas Exchange in Aquatic Animals
3:05
Simple Aquatic Animals
3:06
Gills & Gas Exchange in Complex Aquatic Animals
3:49
Countercurrent Exchange
6:12
Gas Exchange in Terrestrial Animals
13:46
Earthworms
14:07
Internal Respiratory
15:35
Insects
16:55
Circulatory Fluid
19:06
The Human Respiratory System
21:21
Nasal Cavity, Pharynx, Larynx, and Epiglottis
21:50
Bronchus, Bronchiole, Trachea, and Alveoli
23:38
Pulmonary Surfactants
28:05
Circulatory System: Hemoglobin
29:13
Ventilation
30:28
Inspiration/Expiration: Diaphragm, Thorax, and Abdomen
30:33
Breathing Control Center: Regulation of pH
34:34
Example 1: Tracheal System in Insects
39:08
Example 2: Countercurrent Exchange
42:09
Example 3: Respiratory System
44:10
Example 4: Diaphragm, Ventilation, pH, and Regulation of Breathing
45:31
The Circulatory System

1h 20m 21s

Intro
0:00
Types of Circulatory Systems
0:07
Circulatory System Overview
0:08
Open Circulatory System
3:19
Closed Circulatory System
5:58
Blood Vessels
7:51
Arteries
8:16
Veins
10:01
Capillaries
12:35
Vasoconstriction and Vasodilation
13:10
Vasoconstriction
13:11
Vasodilation
13:47
Thermoregulation
14:32
Blood
15:53
Plasma
15:54
Cellular Component: Red Blood Cells
17:41
Cellular Component: White Blood Cells
20:18
Platelets
21:14
Blood Types
21:35
Clotting
27:04
Blood, Fibrin, and Clotting
27:05
Hemophilia
30:26
The Heart
31:09
Structures and Functions of the Heart
31:19
Pulmonary and Systemic Circulation
40:20
Double Circuit: Pulmonary Circuit and Systemic Circuit
40:21
The Cardiac Cycle
42:35
The Cardiac Cycle
42:36
Autonomic Nervous System
50:00
Hemoglobin
51:25
Hemoglobin & Hemocyanin
51:26
Oxygen-Hemoglobin Dissociation Curve
55:30
Oxygen-Hemoglobin Dissociation Curve
55:44
Transport of Carbon Dioxide
1:06:31
Transport of Carbon Dioxide
1:06:37
Example 1: Pathway of Blood
1:12:48
Example 2: Oxygenated Blood, Pacemaker, and Clotting
1:15:24
Example 3: Vasodilation and Vasoconstriction
1:16:19
Example 4: Oxygen-Hemoglobin Dissociation Curve
1:18:13
The Digestive System

56m 11s

Intro
0:00
Introduction to Digestion
0:07
Digestive Process
0:08
Intracellular Digestion
0:45
Extracellular Digestion
1:44
Types of Digestive Tracts
2:08
Gastrovascular Cavity
2:09
Complete Gastrointestinal Tract (Alimentary Canal)
3:54
'Crop'
4:43
The Human Digestive System
5:41
Structures of the Human Digestive System
5:47
The Oral Cavity and Esophagus
7:47
Mechanical & Chemical Digestion
7:48
Salivary Glands
8:55
Pharynx and Epigloltis
9:43
Peristalsis
11:35
The Stomach
12:57
Lower Esophageal Sphincter
13:00
Gastric Gland, Parietal Cells, and Pepsin
14:32
Mucus Cell
15:48
Chyme & Pyloric Sphincter
17:32
The Pancreas
18:31
Endocrine and Exocrine
19:03
Amylase
20:05
Proteases
20:51
Lipases
22:20
The Liver
23:08
The Liver & Production of Bile
23:09
The Small Intestine
24:37
The Small Intestine
24:38
Duodenum
27:44
Intestinal Enzymes
28:41
Digestive Enzyme
33:30
Site of Production: Mouth
33:43
Site of Production: Stomach
34:03
Site of Production: Pancreas
34:16
Site of Production: Small Intestine
36:18
Absorption of Nutrients
37:51
Absorption of Nutrients: Jejunum and Ileum
37:52
The Large Intestine
44:52
The Large Intestine: Colon, Cecum, and Rectum
44:53
Regulation of Digestion by Hormones
46:55
Gastrin
47:21
Secretin
47:50
Cholecystokinin (CCK)
48:00
Example 1: Intestinal Cell, Bile, and Digestion of Fats
48:29
Example 2: Matching
51:06
Example 3: Digestion and Absorption of Starch
52:18
Example 4: Large Intestine and Gastric Fluids
54:52
The Excretory System

1h 12m 14s

Intro
0:00
Nitrogenous Wastes
0:08
Nitrogenous Wastes Overview
0:09
NH3
0:39
Urea
2:43
Uric Acid
3:31
Osmoregulation
4:56
Osmoregulation
5:05
Saltwater Fish vs. Freshwater Fish
8:58
Types of Excretory Systems
13:42
Protonephridia
13:50
Metanephridia
16:15
Malpighian Tubule
19:05
The Human Excretory System
20:45
Kidney, Ureter, bladder, Urethra, Medula, and Cortex
20:53
Filtration, Reabsorption and Secretion
22:53
Filtration
22:54
Reabsorption
24:16
Secretion
25:20
The Nephron
26:23
The Nephron
26:24
The Nephron, cont.
41:45
Descending Loop of Henle
41:46
Ascending Loop of Henle
45:45
Antidiuretic Hormone
54:30
Antidiuretic Hormone (ADH)
54:31
Aldosterone
58:58
Aldosterone
58:59
Example 1: Nephron of an Aquatic Mammal
1:04:21
Example 2: Uric Acid & Saltwater Fish
1:06:36
Example 3: Nephron
1:09:14
Example 4: Gastrointestinal Infection
1:10:41
The Endocrine System

51m 12s

Intro
0:00
The Endocrine System Overview
0:07
Thyroid
0:08
Exocrine
1:56
Pancreas
2:44
Paracrine Signaling
4:06
Pheromones
5:15
Mechanisms of Hormone Action
6:06
Reception, Transduction, and Response
7:06
Classes of Hormone
10:05
Negative Feedback: Testosterone Example
12:16
The Pancreas
15:11
The Pancreas & islets of Langerhan
15:12
Insulin
16:02
Glucagon
17:28
The Anterior Pituitary
19:25
Thyroid Stimulating Hormone
20:24
Adrenocorticotropic Hormone
21:16
Follide Stimulating Hormone
22:04
Luteinizing Hormone
22:45
Growth Hormone
23:45
Prolactin
24:24
Melanocyte Stimulating Hormone
24:55
The Hypothalamus and Posterior Pituitary
25:45
Hypothalamus, Oxytocin, Antidiuretic Hormone (ADH), and Posterior Pituitary
25:46
The Adrenal Glands
31:20
Adrenal Cortex
31:56
Adrenal Medulla
34:29
The Thyroid
35:54
Thyroxine
36:09
Calcitonin
40:27
The Parathyroids
41:44
Parathyroids Hormone (PTH)
41:45
The Ovaries and Testes
43:32
Estrogen, Progesterone, and Testosterone
43:33
Example 1: Match the Following Hormones with their Descriptions
45:38
Example 2: Pancreas, Endocrine Organ & Exocrine Organ
47:06
Example 3: Insulin and Glucagon
48:28
Example 4: Increased Level of Cortisol in Blood
50:25
The Nervous System

1h 10m 38s

Intro
0:00
Types of Nervous Systems
0:28
Nerve Net
0:37
Flatworm
1:07
Cephalization
1:52
Arthropods
2:44
Echinoderms
3:11
Nervous System Organization
3:40
Nervous System Organization Overview
3:41
Automatic Nervous System: Sympathetic & Parasympathetic
4:42
Neuron Structure
6:57
Cell Body & Dendrites
7:16
Axon & Axon Hillock
8:20
Synaptic Terminals, Mylenin, and Nodes of Ranvier
9:01
Pre-synaptic and Post-synaptic Cells
10:16
Pre-synaptic Cells
10:17
Post-synaptic Cells
11:05
Types of Neurons
11:50
Sensory Neurons
11:54
Motor Neurons
13:12
Interneurons
14:24
Resting Potential
15:14
Membrane Potential
15:25
Resting Potential: Chemical Gradient
16:06
Resting Potential: Electrical Gradient
19:18
Gated Ion Channels
24:40
Voltage-Gated & Ligand-Gated Ion Channels
24:48
Action Potential
30:09
Action Potential Overview
30:10
Step 1
32:07
Step 2
32:17
Step 3
33:12
Step 4
35:14
Step 5
36:39
Action Potential Transmission
39:04
Action Potential Transmission
39:05
Speed of Conduction
41:19
Saltatory Conduction
42:58
The Synapse
44:17
The Synapse: Presynaptic & Postsynaptic Cell
44:31
Examples of Neurotransmitters
50:05
Brain Structure
51:57
Meniges
52:19
Cerebrum
52:56
Corpus Callosum
53:13
Gray & White Matter
53:38
Cerebral Lobes
55:35
Cerebellum
56:00
Brainstem
56:30
Medulla
56:51
Pons
57:22
Midbrain
57:55
Thalamus
58:25
Hypothalamus
58:58
Ventricles
59:51
The Spinal Cord
1:00:29
Sensory Stimuli
1:00:30
Reflex Arc
1:01:41
Example 1: Automatic Nervous System
1:04:38
Example 2: Synaptic Terminal and the Release of Neurotransmitters
1:06:22
Example 3: Volted-Gated Ion Channels
1:08:00
Example 4: Neuron Structure
1:09:26
Musculoskeletal System

39m 29s

Intro
0:00
Skeletal System Types and Function
0:30
Skeletal System
0:31
Exoskeleton
1:34
Endoskeleton
2:32
Skeletal System Components
2:55
Bone
3:06
Cartilage
5:04
Tendons
6:18
Ligaments
6:34
Skeletal Muscle
6:52
Skeletal Muscle
7:24
Sarcomere
9:50
The Sliding Filament Theory
13:12
The Sliding Filament Theory: Muscle Contraction
13:13
The Neuromuscular Junction
17:24
The Neuromuscular Junction: Motor Neuron & Muscle Fiber
17:26
Sarcolemma, Sarcoplasmic
21:54
Tropomyosin & Troponin
23:35
Summation and Tetanus
25:26
Single Twitch, Summation of Two Twitches, and Tetanus
25:27
Smooth Muscle
28:50
Smooth Muscle
28:58
Cardiac Muscle
30:40
Cardiac Muscle
30:42
Summary of Muscle Types
32:07
Summary of Muscle Types
32:08
Example 1: Contraction and Skeletal Muscle
33:15
Example 2: Skeletal Muscle and Smooth Muscle
36:23
Example 3: Muscle Contraction, Bone, and Nonvascularized Connective Tissue
37:31
Example 4: Sarcomere
38:17
The Immune System

1h 24m 28s

Intro
0:00
The Lymphatic System
0:16
The Lymphatic System Overview
0:17
Function 1
1:23
Function 2
2:27
Barrier Defenses
3:41
Nonspecific vs. Specific Immune Defenses
3:42
Barrier Defenses
5:12
Nonspecific Cellular Defenses
7:50
Nonspecific Cellular Defenses Overview
7:53
Phagocytes
9:29
Neutrophils
11:43
Macrophages
12:15
Natural Killer Cells
12:55
Inflammatory Response
14:19
Complement
18:16
Interferons
18:40
Specific Defenses - Acquired Immunity
20:12
T lymphocytes and B lymphocytes
20:13
B Cells
23:35
B Cells & Humoral Immunity
23:41
Clonal Selection
29:50
Clonal Selection
29:51
Primary Immune Response
34:28
Secondary Immune Response
35:31
Cytotoxic T Cells
38:41
Helper T Cells
39:20
Major Histocompatibility Complex Molecules
40:44
Major Histocompatibility Complex Molecules
40:55
Helper T Cells
52:36
Helper T Cells
52:37
Mechanisms of Antibody Action
59:00
Mechanisms of Antibody Action
59:01
Opsonization
1:00:01
Complement System
1:01:57
Classes of Antibodies
1:02:45
IgM
1:03:01
IgA
1:03:17
IgG
1:03:53
IgE
1:04:10
Passive and Active Immunity
1:05:00
Passive Immunity
1:05:01
Active Immunity
1:07:49
Recognition of Self and Non-Self
1:09:32
Recognition of Self and Non-Self
1:09:33
Self-Tolerance & Autoimmune Diseases
1:10:50
Immunodeficiency
1:13:27
Immunodeficiency
1:13:28
Chemotherapy
1:13:56
AID
1:14:27
Example 1: Match the Following Terms with their Descriptions
1:15:26
Example 2: Three Components of Non-specific Immunity
1:17:59
Example 3: Immunodeficient
1:21:19
Example 4: Self-tolerance and Autoimmune Diseases
1:23:07
Section 11: Animal Reproduction and Development
Reproduction

1h 1m 41s

Intro
0:00
Asexual Reproduction
0:17
Fragmentation
0:53
Fission
1:54
Parthenogenesis
2:38
Sexual Reproduction
4:00
Sexual Reproduction
4:01
Hermaphrodite
8:08
The Male Reproduction System
8:54
Seminiferous Tubules & Leydig Cells
8:55
Epididymis
9:48
Seminal Vesicle
11:19
Bulbourethral
12:37
The Female Reproductive System
13:25
Ovaries
13:28
Fallopian
14:50
Endometrium, Uterus, Cilia, and Cervix
15:03
Mammary Glands
16:44
Spermatogenesis
17:08
Spermatogenesis
17:09
Oogenesis
21:01
Oogenesis
21:02
The Menstrual Cycle
27:56
The Menstrual Cycle: Ovarian and Uterine Cycle
27:57
Summary of the Ovarian and Uterine Cycles
42:54
Ovarian
42:55
Uterine
44:51
Oxytocin and Prolactin
46:33
Oxytocin
46:34
Prolactin
47:00
Regulation of the Male Reproductive System
47:28
Hormones: GnRH, LH, FSH, and Testosterone
47:29
Fertilization
50:11
Fertilization
50:12
Structures of Egg
50:28
Acrosomal Reaction
51:36
Cortical Reaction
53:09
Example 1: List Three Differences between Spermatogenesis and oogenesis
55:36
Example 2: Match the Following Terms to their Descriptions
57:34
Example 3: Pregnancy and the Ovarian Cycle
58:44
Example 4: Hormone
1:00:43
Development

50m 5s

Intro
0:00
Cleavage
0:31
Cleavage
0:32
Meroblastic
2:06
Holoblastic Cleavage
3:23
Protostomes
4:34
Deuterostomes
5:13
Totipotent
5:52
Blastula Formation
6:42
Blastula
6:46
Gastrula Formation
8:12
Deuterostomes
11:02
Protostome
11:44
Ectoderm
12:17
Mesoderm
12:55
Endoderm
13:40
Cytoplasmic Determinants
15:19
Cytoplasmic Determinants
15:23
The Bird Embryo
22:52
Cleavage
23:35
Blastoderm
23:55
Primitive Streak
25:38
Migration and Differentiation
27:09
Extraembryonic Membranes
28:33
Extraembryonic Membranes
28:34
Chorion
30:02
Yolk Sac
30:36
Allantois
31:04
The Mammalian Embryo
32:18
Cleavage
32:28
Blastocyst
32:44
Trophoblast
34:37
Following Implantation
35:48
Organogenesis
37:04
Organogenesis, Notochord and Neural Tube
37:05
Induction
40:15
Induction
40:39
Fate Mapping
41:40
Example 1: Processes and Stages of Embryological Development
42:49
Example 2: Transplanted Cells
44:33
Example 3: Germ Layer
46:41
Example 4: Extraembryonic Membranes
47:28
Section 12: Animal Behavior
Animal Behavior

47m 48s

Intro
0:00
Introduction to Animal Behavior
0:05
Introduction to Animal Behavior
0:06
Ethology
1:04
Proximate Cause & Ultimate Cause
1:46
Fixed Action Pattern
3:07
Sign Stimulus
3:40
Releases and Example
3:55
Exploitation and Example
7:23
Learning
8:56
Habituation, Associative Learning, and Imprinting
8:57
Habituation
10:03
Habituation: Definition and Example
10:04
Associative Learning
11:47
Classical
12:19
Operant Conditioning
13:40
Positive & Negative Reinforcement
14:59
Positive & Negative Punishment
16:13
Extinction
17:28
Imprinting
17:47
Imprinting: Definition and Example
17:48
Social Behavior
20:12
Cooperation
20:38
Agonistic
21:37
Dorminance Heirarchies
23:23
Territoriality
24:08
Altruism
24:55
Communication
26:56
Communication
26:57
Mating
32:38
Mating Overview
32:40
Promiscuous
33:13
Monogamous
33:32
Polygamous
33:48
Intrasexual
34:22
Intersexual Selection
35:08
Foraging
36:08
Optimal Foraging Model
36:39
Foraging
37:47
Movement
39:12
Kinesis
39:20
Taxis
40:17
Migration
40:54
Lunar Cycles
42:02
Lunar Cycles
42:08
Example 1: Types of Conditioning
43:19
Example 2: Match the Following Terms to their Descriptions
44:12
Example 3: How is the Optimal Foraging Model Used to Explain Foraging Behavior
45:47
Example 4: Learning
46:54
Section 13: Ecology
Biomes

58m 49s

Intro
0:00
Ecology
0:08
Ecology
0:14
Environment
0:22
Integrates
1:41
Environment Impacts
2:20
Population and Distribution
3:20
Population
3:21
Range
4:50
Potential Range
5:10
Abiotic
5:46
Biotic
6:22
Climate
7:55
Temperature
8:40
Precipitation
10:00
Wind
10:37
Sunlight
10:54
Macroclimates & Microclimates
11:31
Other Abiotic Factors
12:20
Geography
12:28
Water
13:17
Soil and Rocks
13:48
Sunlight
14:42
Sunlight
14:43
Seasons
15:43
June Solstice, December Solstice, March Equinox, and September Equinox
15:44
Tropics
19:00
Seasonability
19:39
Wind and Weather Patterns
20:44
Vertical Circulation
20:51
Surface Wind Patterns
25:18
Local Climate Effects
26:51
Local Climate Effects
26:52
Terrestrial Biomes
30:04
Biome
30:05
Forest
31:02
Tropical Forest
32:00
Tropical Forest
32:01
Temperate Broadleaf Forest
32:55
Temperate Broadleaf Forest
32:56
Coniferous/Taiga Forest
34:10
Coniferous/Taiga Forest
34:11
Desert
36:05
Desert
36:06
Grassland
37:45
Grassland
37:46
Tundra
40:09
Tundra
40:10
Freshwater Biomes
42:25
Freshwater Biomes: Zones
42:27
Eutrophic Lakes
44:24
Oligotrophic Lakes
45:01
Lakes Turnover
46:03
Rivers
46:51
Wetlands
47:40
Estuary
48:11
Marine Biomes
48:45
Marine Biomes: Zones
48:46
Example 1: Diversity of Life
52:18
Example 2: Marine Biome
53:08
Example 3: Season
54:20
Example 4: Biotic vs. Abiotic
55:54
Population

41m 16s

Intro
0:00
Population
0:07
Size 'N'
0:16
Density
0:41
Dispersion
1:01
Measure Population: Count Individuals, Sampling, and Proxymeasure
2:26
Mortality
7:29
Mortality and Survivorship
7:30
Age Structure Diagrams
11:52
Expanding with Rapid Growth, Expanding, and Stable
11:58
Population Growth
15:39
Biotic Potential & Exponential Growth
15:43
Logistic Population Growth
19:07
Carrying Capacity (K)
19:18
Limiting Factors
20:55
Logistic Model and Oscillation
22:55
Logistic Model and Oscillation
22:56
Changes to the Carrying Capacity
24:36
Changes to the Carrying Capacity
24:37
Growth Strategies
26:07
'r-selected' or 'r-strategist'
26:23
'K-selected' or 'K-strategist'
27:47
Human Population
30:15
Human Population and Exponential Growth
30:21
Case Study - Lynx and Hare
31:54
Case Study - Lynx and Hare
31:55
Example 1: Estimating Population Size
34:35
Example 2: Population Growth
36:45
Example 3: Carrying Capacity
38:17
Example 4: Types of Dispersion
40:15
Communities

1h 6m 26s

Intro
0:00
Community
0:07
Ecosystem
0:40
Interspecific Interactions
1:14
Competition
2:45
Competition Overview
2:46
Competitive Exclusion
3:57
Resource Partitioning
4:45
Character Displacement
6:22
Predation
7:46
Predation
7:47
True Predation
8:05
Grazing/ Herbivory
8:39
Predator Adaptation
10:13
Predator Strategies
10:22
Physical Features
11:02
Prey Adaptation
12:14
Prey Adaptation
12:23
Aposematic Coloration
13:35
Batesian Mimicry
14:32
Size
15:42
Parasitism
16:48
Symbiotic Relationship
16:54
Ectoparasites
18:31
Endoparasites
18:53
Hyperparisitism
19:21
Vector
20:08
Parasitoids
20:54
Mutualism
21:23
Resource - Resource mutualism
21:34
Service - Resource Mutualism
23:31
Service - Service Mutualism: Obligate & Facultative
24:23
Commensalism
26:01
Commensalism
26:03
Symbiosis
27:31
Trophic Structure
28:35
Producers & Consumers: Autotrophs & Heterotrophs
28:36
Food Chain
33:26
Producer & Consumers
33:38
Food Web
39:01
Food Web
39:06
Significant Species within Communities
41:42
Dominant Species
41:50
Keystone Species
42:44
Foundation Species
43:41
Community Dynamics and Disturbances
44:31
Disturbances
44:33
Duration
47:01
Areal Coverage
47:22
Frequency
47:48
Intensity
48:04
Intermediate Level of Disturbance
48:20
Ecological Succession
50:29
Primary and Secondary Ecological Succession
50:30
Example 1: Competition Situation & Outcome
57:18
Example 2: Food Chains
1:00:08
Example 3: Ecological Units
1:02:44
Example 4: Disturbances & Returning to the Original Climax Community
1:04:30
Energy and Ecosystems

57m 42s

Intro
0:00
Ecosystem: Biotic & Abiotic Components
0:15
First Law of Thermodynamics & Energy Flow
0:40
Gross Primary Productivity (GPP)
3:52
Net Primary Productivity (NPP)
4:50
Biogeochemical Cycles
7:16
Law of Conservation of Mass & Biogeochemical Cycles
7:17
Water Cycle
10:55
Water Cycle
10:57
Carbon Cycle
17:52
Carbon Cycle
17:53
Nitrogen Cycle
22:40
Nitrogen Cycle
22:41
Phosphorous Cycle
29:34
Phosphorous Cycle
29:35
Climate Change
33:20
Climate Change
33:21
Eutrophication
39:38
Nitrogen
40:34
Phosphorous
41:29
Eutrophication
42:55
Example 1: Energy and Ecosystems
45:28
Example 2: Atmospheric CO2
48:44
Example 3: Nitrogen Cycle
51:22
Example 4: Conversion of a Forest near a Lake to Farmland
53:20
Section 14: Laboratory Review
Laboratory Review

2h 4m 30s

Intro
0:00
Lab 1: Diffusion and Osmosis
0:09
Lab 1: Diffusion and Osmosis
0:10
Lab 1: Water Potential
11:55
Lab 1: Water Potential
11:56
Lab 2: Enzyme Catalysis
18:30
Lab 2: Enzyme Catalysis
18:31
Lab 3: Mitosis and Meiosis
27:40
Lab 3: Mitosis and Meiosis
27:41
Lab 3: Mitosis and Meiosis
31:50
Ascomycota Life Cycle
31:51
Lab 4: Plant Pigments and Photosynthesis
40:36
Lab 4: Plant Pigments and Photosynthesis
40:37
Lab 5: Cell Respiration
49:56
Lab 5: Cell Respiration
49:57
Lab 6: Molecular Biology
55:06
Lab 6: Molecular Biology & Transformation 1st Part
55:07
Lab 6: Molecular Biology
1:01:16
Lab 6: Molecular Biology 2nd Part
1:01:17
Lab 7: Genetics of Organisms
1:07:32
Lab 7: Genetics of Organisms
1:07:33
Lab 7: Chi-square Analysis
1:13:00
Lab 7: Chi-square Analysis
1:13:03
Lab 8: Population Genetics and Evolution
1:20:41
Lab 8: Population Genetics and Evolution
1:20:42
Lab 9: Transpiration
1:24:02
Lab 9: Transpiration
1:24:03
Lab 10: Physiology of the Circulatory System
1:31:05
Lab 10: Physiology of the Circulatory System
1:31:06
Lab 10: Temperature and Metabolism in Ectotherms
1:38:25
Lab 10: Temperature and Metabolism in Ectotherms
1:38:30
Lab 11: Animal Behavior
1:40:52
Lab 11: Animal Behavior
1:40:53
Lab 12: Dissolved Oxygen & Aquatic Primary Productivity
1:45:36
Lab 12: Dissolved Oxygen & Aquatic Primary Productivity
1:45:37
Lab 12: Primary Productivity
1:49:06
Lab 12: Primary Productivity
1:49:07
Example 1: Chi-square Analysis
1:56:31
Example 2: Mitosis
1:59:28
Example 3: Transpiration of Plants
2:00:27
Example 4: Population Genetic
2:01:16
Section 15: The AP Biology Test
Understanding the Basics

13m 2s

Intro
0:00
AP Biology Structure
0:18
Section I
0:31
Section II
1:16
Scoring
2:04
The Four 'Big Ideas'
3:51
Process of Evolution
4:37
Biological Systems Utilize
4:44
Living Systems
4:55
Biological Systems Interact
5:03
Items to Bring to the Test
7:56
Test Taking Tips
9:53
Section 16: Practice Test (Barron's 4th Edition)
AP Biology Practice Exam: Section I, Part A, Multiple Choice Questions 1-31

1h 4m 29s

Intro
0:00
AP Biology Practice Exam
0:14
Multiple Choice 1
0:40
Multiple Choice 2
2:27
Multiple Choice 3
4:30
Multiple Choice 4
6:43
Multiple Choice 5
9:27
Multiple Choice 6
11:32
Multiple Choice 7
12:54
Multiple Choice 8
14:42
Multiple Choice 9
17:06
Multiple Choice 10
18:42
Multiple Choice 11
20:49
Multiple Choice 12
23:23
Multiple Choice 13
26:20
Multiple Choice 14
27:52
Multiple Choice 15
28:44
Multiple Choice 16
33:07
Multiple Choice 17
35:31
Multiple Choice 18
39:43
Multiple Choice 19
40:37
Multiple Choice 20
42:47
Multiple Choice 21
45:58
Multiple Choice 22
49:49
Multiple Choice 23
53:44
Multiple Choice 24
55:12
Multiple Choice 25
55:59
Multiple Choice 26
56:50
Multiple Choice 27
58:08
Multiple Choice 28
59:54
Multiple Choice 29
1:01:36
Multiple Choice 30
1:02:31
Multiple Choice 31
1:03:50
AP Biology Practice Exam: Section I, Part A, Multiple Choice Questions 32-63

50m 44s

Intro
0:00
AP Biology Practice Exam
0:14
Multiple Choice 32
0:27
Multiple Choice 33
4:14
Multiple Choice 34
5:12
Multiple Choice 35
6:51
Multiple Choice 36
10:46
Multiple Choice 37
11:27
Multiple Choice 38
12:17
Multiple Choice 39
13:49
Multiple Choice 40
17:02
Multiple Choice 41
18:27
Multiple Choice 42
19:35
Multiple Choice 43
21:10
Multiple Choice 44
23:35
Multiple Choice 45
25:00
Multiple Choice 46
26:20
Multiple Choice 47
28:40
Multiple Choice 48
30:14
Multiple Choice 49
31:24
Multiple Choice 50
32:45
Multiple Choice 51
33:41
Multiple Choice 52
34:40
Multiple Choice 53
36:12
Multiple Choice 54
38:06
Multiple Choice 55
38:37
Multiple Choice 56
40:00
Multiple Choice 57
41:18
Multiple Choice 58
43:12
Multiple Choice 59
44:25
Multiple Choice 60
45:02
Multiple Choice 61
46:10
Multiple Choice 62
47:54
Multiple Choice 63
49:01
AP Biology Practice Exam: Section I, Part B, Grid In

21m 52s

Intro
0:00
AP Biology Practice Exam
0:17
Grid In Question 1
0:29
Grid In Question 2
3:49
Grid In Question 3
11:04
Grid In Question 4
13:18
Grid In Question 5
17:01
Grid In Question 6
19:30
AP Biology Practice Exam: Section II, Long Free Response Questions

31m 22s

Intro
0:00
AP Biology Practice Exam
0:18
Free Response 1
0:29
Free Response 2
20:47
AP Biology Practice Exam: Section II, Short Free Response Questions

24m 41s

Intro
0:00
AP Biology Practice Exam
0:15
Free Response 3
0:26
Free Response 4
5:21
Free Response 5
8:25
Free Response 6
11:38
Free Response 7
14:48
Free Response 8
22:14
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Lecture Comments (12)

0 answers

Post by Mike Qiu on July 31, 2021

What does "butt off" mean?

2 answers

Last reply by: Ben C.
Wed Aug 25, 2021 3:38 PM

Post by Peter Fraser on February 23, 2017

44:18 Central Vacuole: Actually, I believe this organelle can occupy as much as 95% of the volume of certain mature plant cells, so it can become really massive at full turgor.

0 answers

Post by Peter Fraser on February 14, 2017

31:19: Possibly nit-picking, but I believe the contents nucleus are not considered part of the cytoplasm, hence the term nucleoplasm to specifically describe the contents of the nucleus, not including the nucleolus.  I think the word used describe both the cytoplasm and nucleoplasm is protoplasm.

1 answer

Last reply by: Dr Carleen Eaton
Wed Jan 8, 2014 7:17 PM

Post by Yousra Hassan on December 25, 2013

I want to thank you for relating a lot of the topics you explain to the real world by referring to associated diseases and illnesses. It's something I appreciate very much and really deepens my understanding of the course.

1 answer

Last reply by: Moynul Hussain
Wed Oct 30, 2013 6:35 PM

Post by Moynul Hussain on October 30, 2013

isnt pili also called cilia because thats what i learned in school.

2 answers

Last reply by: felix michoutchenko
Tue Nov 1, 2011 1:18 PM

Post by felix michoutchenko on October 19, 2011

I need to find the correct information on this:

Insulin is a glycoprotein. Where in the cell is the sugar group added to the protein? Golgi or ER?

My professor says it's ER but I found in two biology books that it is the Golgi.
What do you say?

It's a question of getting my mark correct or wrong.

please help!

Thank you.

Subcellular Structure

  • Bacteria have cell walls containing peptidogylcan. Some bacteria are covered by a capsule that helps them to evade the immune system.
  • The genetic material in bacteria found in the nucleoid region. Some bacteria also have small rings of DNA called plasmids, which contain additional genes.
  • Pili are projections from the bacterial surface. Sex pili transfer DNA from one cell to another.
  • Flagella provide a means of motility in some prokaryotes.
  • Eukaryotic cells contain membrane bound organelles including rough and smooth endoplasmic reticulum, Golgi apparatus, mitochondria, lysosomes, peroxisomes and ribosomes.
  • Eukaryotic DNA is organized as chromosomes bound by histone proteins and is located within a membrane bound nucleus. The nucleolus is the site of ribosomal RNA synthesis.
  • The cytoskeleton is a network of filaments composed of microtubules, microfilaments and intermediate filaments.
  • Animal cells do not have cell walls. The primary cell walls in plants contain cellulose. Plants may also have a secondary cell wall composed of both cellulose and lignin.
  • Plant cells have a large central vacuole and organelles called plastids, including chloroplasts, the site of photosynthesis.

Subcellular Structure

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

  • Intro 0:00
  • Prokaryotic Cells 0:09
    • Shapes of Prokaryotic Cells
    • Cell Wall
    • Capsule
    • Pili/Fimbria
    • Flagella
    • Nucleoid
    • Plasmid
    • Ribosomes
  • Eukaryotic Cells (Animal Cell Structure) 8:01
    • Plasma Membrane
    • Microvilli
    • Nucleus
    • Nucleolus
    • Ribosomes: Free and Bound
    • Rough Endoplasmic Reticulum (RER)
  • Eukaryotic Cells (Animal Cell Structure), cont. 14:51
    • Endoplasmic Reticulum: Smooth and Rough
    • Golgi Apparatus
    • Vacuole
    • Lysosome
    • Mitochondria
    • Peroxisomes
  • Cytoskeleton 30:41
    • Cytoplasm and Cytosol
    • Microtubules: Centrioles, Spindel Fibers, Clagell, Cillia
    • Microfilaments
    • Intermediate Filaments and Kerotin
  • Eukaryotic Cells (Plant Cell Structure) 40:08
    • Plasma Membrane, Primary Cell Wall, and Secondary Cell Wall
    • Middle Lamella
    • Central Cauole
    • Plastids: Leucoplasts, Chromoplasts, Chrloroplasts
    • Chloroplasts
  • Example 1: Structures and Functions 48:46
  • Example 2: Cell Walls 51:19
  • Example 3: Cytoskeleton 52:53
  • Example 4: Antibiotics and the Endosymbiosis Theory 56:55

Transcription: Subcellular Structure

Welcome to Educator.com.0000

We are going to continue our discussion of cell structure and function with the topic of subcellular structure.0002

We will start out by talking about the subcellular structure of prokaryotic cells and then, go on to talk about two types of eukaryotic cells- plant cells and animal cells.0010

Looking at prokaryotic cells, the first thing is they come in different shapes.0022

One shape is cocci, for example, streptococcus.0028

Cocci is plural, and this is spherical in shape, so round cells versus bacilli, which are rod-shaped and vibrio, which are actually curved rods.0034

They are shaped, sort of, like a comma; and cholerae the causative agent for the disease cholera, the severe gastrointestinal illness, is actually called vibrio cholerae.0058

That bacteria has this curved rod shape.0069

You look at a bacterial cell, you, first, will notice the shape, and this actually has a shape of a bacillus. It is rod-shaped.0072

The next thing you will notice is the cell wall. Cell walls in bacteria contain peptidoglycan, and the name tells you what it is composed of.0080

It is composed of short peptides, so peptido and polysaccharides, that is the glycan part of the word.0096

And there are two general types of cell walls- gram-positive and gram-negative.0105

Gram-positive cell walls contain a greater amount of peptidoglycan.0116

Gram-negative cells have only a thin layer of peptidoglycan, and the names gram-positive and gram-negative come from a technique called gram staining.0121

In gram staining, cells are stained with a purplish dye called crystal violet.0131

The crystal violet is, then, rinsed off with alcohol, and the cells are counter stained with a pinkish dye like safranin.0139

Gram-positive cells, because of their thick layer of peptidoglycan, they retain the crystal violet. They retain the purple dye, and they appear purple.0156

Gram-positive cells on gram stain look purple under the microscope.0168

Gram-negative cells, when you rinse the crystal violet, it does not really rinse out of the gram-positive cells.0174

But the gram-negative cells do not retain that purple dye, as well, because they just have a thin layer of peptidoglycan.0181

What happen is, when you counter stain, the cells retain that dye and they appear pink, so gram-negative cells appear pink.0187

Gram-positive cells appear purple, and that is due to a difference in the composition of their cell walls.0196

In addition to the cell walls, some bacteria are covered by a layer called a capsule.0204

This is usually composed of polysaccharides, and what the capsule does is it helps the bacterial cell to evade the immune system.0214

It is sort of a covering that allows it to slip in to a host cell.0229

Some bacterial cells have projections from the surface that are called pili. Another name for these, you may hear, is fimbriae.0235

Pili or fimbriae can have a couple of purposes. One is that they allow for attachment.0250

They allow the bacteria to attach to surfaces. Also, a specialized type of pili called sex pili, allow for the exchange of genetic materials, exchange of DNA between cells.0256

Some bacteria are modal and one means of motility is flagella.0277

Flagella are structures that can move the bacteria around, and although eukaryotic cells can have flagella, they are actually a different composition in structure.0284

The flagella in bacteria have several parts. They actually have three different parts.0304

The first part is the basal apparatus, and that is embedded in the cell membrane in the cell wall.0309

The basal apparatus should be right around here, and that is the motor for the flagella.0324

It contains a pump that is powered by ATP, which allows the flagella to actually move. It provides the energy for that movement.0329

The second part is the hook, and it lies between the basal apparatus and this last part, which is called the filament; and it connects the two.0340

The hook connects the basal apparatus in this third section called the filament.0349

The filament is made up of a protein called flagellin. This is a part that actually moves, and there is usually one or maybe a few flagella on a modal bacteria.0354

OK, we talked about the outside of the cell, the shape of the cell.0372

Looking at the internal structures of a prokaryotic cell, the genetic material is in a region called the nucleoid region.0376

The DNA is actually circular. There can be additional DNA and circles outside this nucleoid region, and these are called plasmids.0388

Plasmids contain only a few genes, and they are usually not essential to survival.0407

Typical would be virulence gene, genes that allow the bacteria to more easily or effectively infect a host, and bacteria can actually can exchange plasmids.0414

Plasmids are also very important in biotechnology.0425

In addition, prokaryotic cells contain ribosomes. Recall that ribosomes are structures where protein synthesis takes place.0431

Prokaryotic and eukaryotic cells both contain ribosomes, but the ribosomes in bacteria are smaller.0444

They are 70S size, which has to do with their sedimentation, and these are found free in the cytoplasm. They are not bound.0451

Notice that unlike eukaryotic cells, prokaryotic cells do not have a bunch of other membrane-bound organelles.0461

They lack endoplasmic reticulum and Golgi apparatus. They are much less complex than eukaryotic cells.0469

They are also smaller.0476

For eukaryotic cells, we are going to start out by talking about a typical animal cell, and then, we are going to go on to look at a typical plant cell.0483

Alright, first of all, you will notice that they have a cell membrane or a plasma membrane, and what they do not have is a cell wall.0493

There is no cell wall in animal cells.0509

The plasma membrane structure is a phospholipid bilayer.0516

And in the next section, we will talk in detail about the structure of cell membranes, the proteins embedded in cell membranes as well as their function.0519

Some eukaryotic cells, some animal cells, have microvilli, and these are projections.0529

The plasma membrane, instead of just forming more of a circular shape, it is going to project out.0535

It is projections of the plasma membrane and then, there will be a cytoplasm in here, and the purpose of microvilli is to increase surface area.0542

Again, form follows function.0563

You would have to think about what tissues would need to have a great surface area, and that would be tissues that function for absorption such as the gastrointestinal tract.0565

And actually, cells in the intestine do have a lot of microvilli, which increases their surface area, and allows them to be more effective in absorbing nutrients.0576

OK, looking within the cell, the genetic material is contained in a nucleus. Here is the nucleus, and it has a double membrane.0588

Within the nucleus are chromosomes, so nucleus, important points, double membrane, and it contains chromosomes.0602

The DNA are organized into chromosomes, and they are bound by proteins called histones.0619

Now, items need to get into the nucleus such as proteins, and things also need to get out of the nucleus.0626

Since the DNA is the nucleus, this is where DNA synthesis takes place. It is also where transcription of messenger RNA takes place.0634

DNA and then, transcription occurs, and there is messenger RNA that needs to be transported out of the cell; and that occurs via pores.0642

Right here are pores, and these are openings through which materials can cross into or out of the nucleus.0651

If you look at a stained cell, you might notice that there are some dark regions within the nucleus, and these are called nucleoli or singular, here is nucleolus.0663

The nucleolus is a region where ribosomal or rRNA synthesis takes place. It is also an area where the ribosomal subunits are assembled.0679

The proteins for the ribosomal subunits, there is actually two subunits per ribosome.0705

The component proteins are manufactured out here in the cytoplasm, and then, they are imported in through pores.0711

Subunits are imported into the nucleus to the nucleolus, and then, they are assembled together to make the two subunits and the ribosomal RNA is added at that point.0720

You have the assembled subunits.0732

They contain rRNA, and then, they are exported back out to come together as one large ribosome comprised of the two subunits.0734

Alright, the next item we are going to talk about, the next organelle, are ribosomes, and there are actually two types of ribosomes: free and bound.0746

Free ribosomes, it is just the way the name suggests is they are out here free in the cytoplasm, and since form follows function, protein synthesis takes place on ribosomes.0770

Proteins that are destined for the cytoplasm are made by the free ribosomes, so cytoplasmic proteins are made here.0785

Free ribosomes are the site of synthesis of cytoplasmic proteins.0797

Bound ribosomes, well, what are they bound to? They are actually bound to another structure called the endoplasmic reticulum.0806

This is the endoplasmic reticulum, all these sacs and tunnels, and these bumps you see on the surface of part of the endoplasmic reticulum are the bound ribosomes.0812

The area of the endoplasmic reticulum that has these bound ribosomes is called the rough endoplasmic reticulum or sometimes just RER.0824

And the reason it is rough appearing is because of these ribosomes.0833

Here, proteins are to synthesize that are going to be headed for export from the cell.0836

Proteins for export and by export it may mean they are actually leaving the cell entirely, or they may end up just embedded in their cell membrane.0843

Proteins made by the bound ribosomes are either headed completely out of the cell, or they are going to at least end up integrated in the cell membrane.0854

And this makes sense because the ER can, then, package these in the vesicles headed for another organelle, that we will talk about in a second, called the Golgi apparatus.0864

And then, they are ready to go for export.0874

Again, two types of ribosomes: free ribosomes make proteins that are destined for the cytoplasm.0876

Bound ribosomes are found on the endoplasmic reticulum, and they make proteins that are destined either for the cell membrane or to be completely exported from the cell.0882

Alright, this is just the same slide continued so that we can cover the rest of structures in here.0894

I just talked about the rough endoplasmic reticulum, and I focused on the ribosomes; but now, I am talking about the endoplasmic reticulum, itself.0902

The endoplasmic reticulum or just the ER, there are two types.0920

I already mentioned the rough ER. The other type is the smooth ER.0924

Both types are composed of a series of flattened sacs and tubules, and these are often called cisterna- these tubules.0936

Starting with the rough ER, proteins are synthesized by ribosomes on the rough ER.0949

And then, right after these proteins are synthesized, they can enter the lumen of the endoplasmic reticulum through pores - OK - exported proteins made here or made in the rough ER.0954

In addition, the endoplasmic reticulum actually makes a cell membrane. It makes a cell membrane for itself.0977

It actually makes a cell membrane for other parts of the cell, other organelles, the plasma membrane, and those get packaged up in vesicles and get transported out.0986

A couple of functions of the endoplasmic reticulum, site of protein synthesis, site of synthesis of plasma membrane components, the smooth ER has some additional functions.0995

Lipids are made here. Those are components of plasma membranes.1010

This also includes items such as steroids, substances such as steroids.1018

The smooth ER is also the site of detoxification. The smooth ER functions for both synthesis and detoxification.1028

Alcohol is a substance that needs to be detoxified by cells, and in particular, the liver plays a major role in detoxification.1039

You would expect the liver cells to have a lot of smooth ER.1047

OK, two types: rough ER, which functions in protein synthesis, smooth ER, where the synthesis of lipids occurs and detoxification.1051

The protein are made here and lipids, so the substances that are made in the endoplasmic reticulum then leave through vesicles, so vesicles butt off.1063

There is another set of sacs right here called the Golgi apparatus or Golgi bodies.1075

This is a series of flattened sacs, which sits right next to the endoplasmic reticulum often, and communicates with it through vesicle; and there are two sides or two phases to the Golgi.1090

There is one side that is a receiving side, and this is called the cis face, so it is the receiving side.1103

After the Golgi apparatus does its work, it sends items out from vesicles on the trans face.1110

Sometimes people compare the Golgi apparatus to a post office because its job is to process, sort and package materials such as proteins and lipids.1127

The Golgi functions to process, sort and package items including proteins and lipids.1139

What do I mean by a process?1151

Well, the Golgi does things like phosphorylate, so that is phosphate groups. It adds sugars, so glycosylation, so some examples to give you are phosphorylation and glycosylation.1153

And sometimes, the purpose of these is to provide a signal so that the cell knows where the protein is going, so it is, kind of, like a label.1168

The protein is made in the endoplasmic reticulum. Vesicles butt off.1176

They fuse with the Golgi apparatus on the cis phase. They enter the Golgi.1181

They are going to be modified inside.1185

Again, a phosphate group might be added, and that particular group might let the cell know that this is a cell membrane protein1187

so that when it butts off the trans phase in the vesicle, then, that vesicle will fuse with the cell membrane, and if the protein is a membrane protein, it will stay there.1194

If it is not a membrane protein, then, it would just be secreted out of the cell, and there needs to be some sort of signal to tell the cell where a particular protein goes.1205

OK, there are a bunch of/several other structures that we need to cover.1217

I mentioned vesicles, and again, these are ways of the various membranes and membranous structures within the cell to communicate with each other.1225

They are also a way for the cell to export or import materials, so those are vesicles.1234

Large vesicles are called vacuoles. For example, this is might a vacuole.1244

Vacuoles actually do not play as large of a role in animal cells as they do in plant cells, fungi and protist. For example, food vacuoles provide a way for protist to eat.1254

A protist might engulf food so the plasma membrane would invaginate. Food particles would come in, and then, the plasma membrane will pinch off and form a food vacuole with the food inside.1273

Protist also have contractile vacuoles, and the purpose of these is to pump out water.1289

This allows the cell to maintain its osmolarity, and osmolarity is a solute concentration of a fluid.1302

Again, there are vacuoles in animal cells, but they play a bigger role often in other types of cells, plant cells and protist, where you will can find food vacuoles and contractile vacuoles.1310

Another type of structure is lysosomes, which contain lysozymes. OK, these contain enzymes.1322

These are just little membranous sacs that contain enzymes that break down old organelles.1337

They break down, I am just going to say particles, because they can breakdown old organelles. They also breakdown pathogens.1348

Cells in the immune system, macrophages in particular, engulf and ingest foreign particles such as bacteria.1356

Once those are ingested, a vesicle is formed, and that vesicle can actually fuse with the lysosome.1366

And then, when the two fuse together, become one, then the bacteria, the pathogen that is inside, will be digested by these enzymes.1372

As I mentioned, old organelles are also ingested inside a lysosome, and the purpose of that is to refresh and renew the cell.1383

A damage organelle can be digested, and then, its component parts are actually reused by the cell, so they are a continual process of renewal going on.1390

The environment inside a lysosome is very acidic, so the pH in there is low, and the enzymes within a lysosome function best at a low pH.1399

This helps to protect the cell because, let's say this was to burst, if the lysosome burst, and it releases all these enzymes, they could just start eating up the cell.1410

But because the cytoplasmic environment has a higher pH, the enzymes are not going to be as active.1419

Now, if many lysosomes burst at ones, and the pH of the cell overall actually decreased, then there could be a problem.1426

But if it is just a single or a few lysosomes burst, they are going to find themselves in an environment where they do not work very effectively, so the cell is protected that way.1433

There is a set of diseases known as lysosomal storage diseases, and in these, there is an accumulation of macromolecules such a proteins, polysaccharides and lipids.1444

And proteins, polysaccharides and lipids are normally digested in the lysosome, but in people with lysosomal storage diseases, some of the enzymes are either absent or dysfunctional.1455

They end up with an accumulation of these products, and neurons, in particular, are susceptible to damage due to the accumulation of these products, and it causes severe neurological problems.1466

Diseases such as Tay-Sachs disease is an example of a lysosomal storage disease.1477

Taken together, the plasma membrane, the nuclear membrane, the endoplasmic reticulum, Golgi apparatus, lysosome, all those taken together are sometimes known as the endomembrane system.1486

And the different parts of the endomembrane communicate through vesicles,1503

so vesicles coming from the ER to the Golgi fused with the plasma membrane or vesicles fused with a lysosome or a vacuole.1509

The endomembrane system are various structures that often work together and communicate through vesicles.1521

And again, that includes the nuclear membrane, the plasma membrane, the endoplasmic reticulum, the Golgi apparatus, lysosomes, vesicles, vacuoles.1526

Mitochondria are structures that are the site of cellular respiration.1541

Cellular respiration occurs here, and the energy from organic molecules is used to make ATP; and ATP provides the energy for most of the cells functions.1552

A typical cell contains hundreds to even thousands of mitochondria. As expected, cells that use a lot of energy like muscle cells have a lot of mitochondria.1566

The structure of the mitochondria is interesting. It actually has a double membrane.1579

When we talked about the endosymbiotic theory of cell origin in the previous lecture,1586

I mentioned that that double membrane is most likely the result of a membrane from the original larger anaerobic bacteria that engulfed the smaller aerobic bacteria.1591

There is an outer membrane from one of those bacteria and then, the inner membrane that evolved from the smaller bacteria.1603

Mitochondria have a double membrane, and the space between the two membranes is called the intermembrane space.1609

There are folds with the inner membrane, and within those folds is a compartment called the matrix, so there is a double membrane.1619

There is a small space between the two membranes called the intermembrane space, and then, there are folds.1628

These folds are often called cristae/crista and the matrix, which is the compartment formed by these infoldings of the inner membrane.1637

When we talk about cellular respiration, you will see how various enzymes and processes are carried out in certain parts of the mitochondria.1650

Mitochondria have their own DNA. Recall that it has circular DNA like bacterial cells.1663

They also have their own ribosomes. Mitochondrial ribosomes are 70S.1670

They are similar to bacterial ribosomes, and if you want to review those similarities between mitochondrial cells - oh, excuse me - mitochondria and bacterial cells,1677

go ahead and check out the lecture on comparison of prokaryotic and eukaryotic cells and the endosymbiotic theory.1688

The final structure we are going to talk about are peroxisomes.1699

Peroxisomes are bound by a single membrane, and they contain enzymes that detoxify substances.1712

The ox in peroxisomes tells you how they achieve this, and they do it by oxidation; and these are found in both plants and animals.1723

What they do is they transfer hydrogen to oxygen to form hydrogen peroxide, which is H2O2.1732

The only problem is hydrogen peroxide in large amounts is actually toxic to the cell, so peroxisomes have additional enzymes that continue on.1739

They remove an oxygen and release that oxygen and end up with water, which obviously is not harmful to the cell.1748

Again, the purpose of peroxisomes is to detoxify substances. They do that through oxidation resulting in the formation of a hydrogen peroxide.1756

In order to, then, detoxify the hydrogen peroxide, an oxygen is removed which generates water.1768

And they breakdown substances such as fatty acids, and they also detoxify substances such as alcohol.1774

They also play the role in production of bile. Peroxisomes help with the production of bile, and in plants, they help convert fatty acids into sugar.1781

These are formed by enzymes that are made in the cytosol and by vesicles that butt off the endoplasmic reticulum, so vesicles butt off the endoplasmic reticulum.1797

The enzymes are made separately and placed into the peroxisomes, and those are formed.1814

In contrast, lysosomes butt off the Golgi apparatus with the enzymes already contained in them.1820

OK, that summarizes the many organelles and structures in the eukaryotic cell, typical animal cell.1829

But the structures within a eukaryotic cell in both plants and animals actually, these are held in place by cytoskeleton.1839

OK, we talked about the different organelles, and within the plasma membrane is the cytoplasm.1850

The fluid in the cytoplasm, so the space in here is the cytoplasm, and the fluid is called the cytosol.1861

Even though this is describe as a fluid a lot of times, it actually has a texture that is more like a gel.1868

It is not a thin watery fluid. It is more like a gel.1876

Within the cytoplasm are all those organelles we talked about, the nucleus and the mitochondria, the endoplasmic reticulum.1879

The cytoskeleton holds those organelles in place in addition to supporting the cell and giving it its shape.1889

Finally, the cytoskeleton allows for motility.1897

Cytoskeleton is composed of various filaments, and there is three major types of filaments.1901

The first are microtubules. The second are microfilaments, and the third are intermediate filaments.1906

Microtubules are the largest in diameter, so talking about microtubules, they are composed of a protein called tubulin.1927

Tubulin subunits can be added or taken off the end, so there is these individual subunits, and the cell can add on to one end.1939

It can take off of the other end, and that allows for motility.1948

The cytoplasm is not just a rigid structure that does not move. You can think of it more like scaffolding.1952

If you are building a building, you have scaffolding, and when you are finished with one part of the building, you can take it down; or if you need to build a higher part, you can add to it.1959

The cytoskeleton works more like that.1966

There are several important structures that are composed of microtubules. The first one is centrioles, and this picture shows centrioles.1971

Centrioles are found in centrosomes. Their purpose is to organize microtubules.1984

These are one type of MTOC or microtubule organizing center. What this is showing is division of the chromosomes.1997

This is a spindle apparatus right here, spindle fibers, and these spindle fibers are also composed of microtubules.2011

There is a centrosome out here. Within that, are two centrioles organized at right angles, and here is a cross section showing what a centriole looks like.2020

You see that there is nine triplets, and each of these is a microtubule.2034

If you took a centriole, cross-sectioned it, looked down at it, this is what you would see: microtubules organized in this way.2040

The spindle fibers radiate out of these microtubules and then, attach to the chromosomes, and then, during anaphase, the chromosomes are separated.2050

Centrioles play a key role in miosis and mitosis.2060

Recall that plant cells do not have centrosomes, and they do not have centrioles; but they do have microtubule organizing centers.2065

OK, first structure that is made out of microtubules is the centrioles as well as the spindle fibers, so I am going to put spindles.2072

Second structure is flagella. Third structure is cilia, as well as other components of the cytoskeleton.2086

This picture here, this cross section, shows the structure of flagella and the structure of cilia.2095

Flagella and cilia are both organelles of motility.2103

Some animal cells are modal. For example, sperm is modal, and the difference between flagella and cilia is that flagella tend to be longer.2107

There is usually just one flagella or maybe a few flagella at one end of the cell. Protozoa actually use flagella for motility.2117

Again, prokaryotes also have flagella, as well, but they are made out of different molecules, and they have a different structure.2128

Eukaryotic flagella, though, are made up of microtubules.2136

The second organelle of motility is cilia.2140

Cells that use cilia for motility usually have many cilia, so cilia tend to be shorter and there is more of them.2143

Cilia are very effective for moving fluids.2150

The airway in animals is lined with cilia so that if you breathe in dust, other particles, the cilia on your respiratory tract keeps mucus moving out2153

so that, instead of the dust going down in to your lungs, it is going to get pushed out.2167

Some organisms such as paramecium actually use cilia for locomotion rather than just for pushing fluids.2173

OK, microtubules composed of tubulin, centrioles and spindle fibers are made of microtubules.2181

Flagella and cilia are also made of microtubules.2188

Microtubules are fundamental in allowing for cell motility, and that is the first type of filament in the cytoskeleton.2192

The second type of filament are microfilaments. Microfilaments are composed of actin.2200

Actin interacts with the second protein, which is a globular-shaped protein called myosin, and you might be familiar with the words actin myosin from the study of muscle cells.2212

Muscles use actin and myosin interaction for motility.2224

A second type of motility that occurs is that of amoeba using pseudopods to move.2231

An amoeba cell actually form these, almost arms or something, and move around with them, and these are called pseudopods.2238

And these pseudopods, they move because of the action of microfilaments.2246

During cell division, a cleavage furrow is formed, so the two cell, there is one cell, and then it adds on to the size of its plasma membrane.2259

It doubles its organelles. Mitosis occurs, and then, a cleavage furrow forms, and the cell divides into two.2271

This cleavage furrow is also the result of microfilaments.2278

Finally, cytoplasmic streaming that occurs in plant cell and fungi is a result of microfilaments.2285

And we will talk more about that when we talk about plant cells, but it is a circular movement within the cytoplasm.2294

Microfilament functions: first of all their structure, they are composed of actin, and the actin interacts with myosin to allow for contraction of muscles.2300

The second type of movement that can occur is the formation of a pseudopod, which allows amoeba to move as an example.2313

Microfilaments are essential for forming the cleavage furrow for cell division, and finally, microfilaments play an important role in cytoplasmic streaming.2322

So, that was two. The third one is intermediate filaments.2332

As expected, these are intermediate in size between microfilaments and microtubules, and by size, I mean diameter.2336

Microtubules have the largest diameter. Microfilaments have the smallest diameter, and then, intermediate filaments are in between that.2343

And there is not just a single type of subunit that these are made from.2350

There is actually several different types of intermediate filaments, and they each are constructed from a characteristic protein. However, many of these subunits contain keratin.2354

Keratin helps a cell maintain its shape and provides support, and it is keratin with the intermediate filaments that help hold organelles in place.2367

Intermediate filaments are very important in maintenance of cell shape, support and anchoring organelles into place.2390

Keratin is frequently found in epithelial cells. For example our hair and our nails are formed out of keratin.2398

OK, we talked about organelles found in eukaryotic animal cells. We also talked about the cytoskeleton structure.2409

Many of these elements are the same in plant cells, so I am going to just focus on the differences.2419

Plant cells have a plasma membrane or cell membrane just like animal cells.2431

It is a phospholipid bilayer, but looking at what is different, they also have a cell wall; and bacteria have cell walls as well, but the cell wall in plants is made of a different material.2439

The primary cell wall is made of cellulose.2453

Cellulose is a polysaccharide, and this particular polysaccharide of cellulose is embedded in a matrix of polysaccharides and proteins.2460

And the purpose of the cell wall - actually multiple purposes - one, is to maintain the cell shape.2470

The other is to provide protection. The other is to maintain the turgor of the cell.2479

Turgor is a type of rigidity that occurs as a result of water pushing on the cell wall.2486

This is a central vacuole, and it fills with water especially when the cell is in a hypotonic environment, an environment where there is less solutes than inside the cell.2495

The cell is going to take up water, push against the cell wall, and that will make the cell rigid.2504

Unlike animals, plant cells do not have a skeleton, so they use this turgor or this rigidity to maintain their shape.2512

If a plant does not get enough water, it really dries out. It starts to welt the stem and leaves, and that is because it is not maintaining its turgor.2521

In addition, the cell wall prevents lysing of the cell. If a cell takes up too much water, and it does not have a cell wall, it will burst.2531

However, a plant cell cannot take up too much water because at some point, it is going to pump up against this rigid wall, so it prevents the cell from bursting.2543

Some plant cells actually have a second cell wall called a secondary cell wall between the plasma membrane and this primary cell wall, so that is a secondary cell wall.2553

In addition to cellulose, the secondary cell wall contains lignin. Lignin gives a plant wall or the plant cell even greater strength, and lignin is found in wood.2570

A plant sacrifices, it is very rigid because of that, so it cannot bend as much, but, in return, it gets protection. It maintains its shape.2586

Alright, there is a layer associated with the cell wall. Sometimes it is called a separate component.2601

Sometimes, it is considered part of the cell wall, but this layer is called the middle lamella.2607

The middle lamella contains pectin. Pectin is very sticky.2614

It is a polysaccharide. If you make jelly or preserves or something, you will see that pectin is used as a thickener, as a thickening agent.2619

And since it is very sticky, it helps adjacent plant cells hold together.2629

There will be another plant cell right next to this one, let's say right here, and they will actually share a middle lamella.2636

The other cell will have its cell wall here, and then, right between the two is the middle lamella.2645

OK, I already mentioned briefly the central vacuole. The central vacuole is quite large.2654

It can actually take up a third or even half of the cell.2662

The result is that, especially if it absorbs more water, gets bigger, the organelles are found more at the periphery of the cell.2666

The central vacuole functions for storage, so it stores things. It takes care of waste, so waste disposal.2675

It maintains the pH of the cell, and it has a function in maintaining turgor, as I mentioned.2687

Again, in a hypotonic environment, which we will discuss when we talk about plasma membranes and osmolarity.2695

But in a hypotonic environment, in an environment where there is a dilute substance or dilute liquid outside the cell, the plant will take up more water.2702

The central vacuole will become larger. It will push up against the cell wall, and the cell will be rigid.2710

The central vacuole also takes up waste, and it separates it out. It keeps it separate from the rest of the cell so that it cannot cause harm.2718

It isolates those materials.2727

OK, a couple more structures on the plants, plant cells- chloroplast.2732

Chloroplasts are a type of organelle called plastids. Plastids are a set of organelles that are not found in animal cells.2742

They are found in plant cells, but they are not found in animal cells.2751

There are three types. The first type is leucoplast.2756

The second type is chromoplast, and the third type is chloroplast; and this picture, right here, is a chloroplast.2763

Most type of the plastid, you are probably you most familiar about.2776

Starting with leucoplast. Leucoplasts store starch.2780

Because of that, they are found mostly in the roots of plants and in structures called tubers.2789

The eye of the potato, when that starts growing, that is a tuber, so leucoplasts or starch.2795

Chromoplasts contain pigments. In particular, they contain orange and yellow pigments.2801

The reason a carrot appears orange is because of the pigments that are found inside the chromoplasts in the plant cell.2819

Chloroplasts are the site of photosynthesis.2827

This is a chloroplast, and the fluid inside is called the stroma. This is a fluid found inside the chloroplast.2840

You will notice that it has a double membrane just like the mitochondria. Each of these membranous sacs is called a thylakoid, so each sac is a thylakoid.2851

A stack of these together is called a granum, plural is grana, and the enzymes that carry out photosynthesis are found in the thylakoid membrane.2869

As you will notice, this is green, and it is because the chloroplasts contain green pigment. They give parts of the plant, such as the stem and the leaves, their green color.2883

Like mitochondria, there are features of chloroplast that are similar to bacteria and provide evidence for the endosymbiotic theory of eukaryotic origin.2894

Like mitochondria, they have circular DNA. They have a double membrane.2907

They divide by or reproduce by binary fission, and they have their own ribosomes that are similar in structure to bacterial ribosomes. They are 70S ribosomes.2912

Alright, we can do a few examples now.2931

Example one: match each organelle with its description.2933

We have Golgi apparatus, mitochondria, chloroplast, lysosome and endoplasmic reticulum.2936

Looking down at the descriptions, the first description, the site of photosynthesis, well, we just covered that. The site of photosynthesis is the chloroplast.2945

Chloroplast contain thylakoid stacked up into grana, and the thylakoid membrane contains the enzymes that carry out photosynthesis.2957

B: contains hydrolytic enzymes, which digest old organelles and pathogens. Hydrolytic enzymes are found in lysosomes.2968

Recall that lysosomes are present only in animal cells.2979

They are not found in plant cells, and their function is to breakdown old organelles so their parts can be reused2983

and also to destroy pathogens that have been ingested by the cells of the immune system.2990

OK, C: site of production of ATP from energy released from organic molecules. That is the mitochondria.2999

The mitochondria is the site of cellular respiration. ATP is made there, and ATP provides the energy for most functions in the cell.3008

D: site of production of proteins destined for secretion from the cell and production of lipids and detoxification of substances. That is describing the endoplasmic reticulum.3019

The rough endoplasmic reticulum has ribosomes bound to it, and it is a site of production of proteins that are going to be secreted from the cell or going to end up in the cell membrane.3031

The smooth endoplasmic reticulum is the site of the production of lipids, and it is also the site of detoxification of certain substances.3041

Series of flattened sacs, this is E, site of processing, sorting and packaging of proteins made in the rough ER. It also produces polysaccharides, and this is Golgi apparatus.3051

The Golgi apparatus, remember, is the center where the proteins made in the endoplasmic reticulum are sorted out.3063

They are phosphorylated or they are glycosylated. They are packaged in vesicles, and they are sent off to their destination.3071

Example two: what are the functions of the cell wall?3081

The functions of the cell walls, we talked about cell walls in plants because animals do not have cell walls- multiple functions3086

One is they provide the cell with strength. They maintain the turgor of the cell.3094

They prevent lysis, so they prevent the cell from bursting when it is in an environment where it might absorb a lot of water, and if it over absorbs water it will lyse.3104

Instead of lysing though, if the plant absorbs water in a central vacuole, that is just going to push against the cell wall3115

and maintains the cell's shape and rigidity and maintain the shape of the plant through turgor.3123

Strength, turgor prevents lysis, and it also provides protection.3129

One of the primary and secondary walls of cell plant is composed of cell walls of plants composed of.3136

The primary cell wall is mainly made out of cellulose, which is a polysaccharide, and it is embedded in a matrix of various polysaccharides and proteins.3143

Secondary cell walls also contain cellulose, and they contain a second polymer called lignin, which give them additional strength.3153

What are the cell walls of fungi primarily composed of? Fungi have cell walls, as well, but these are composed of chitin.3162

Example three: name three structures composed of microtubules, and list their functions.3176

We talked about multiple structures that are made out of microtubules. The first one was centrioles.3183

Centrioles help to organize microtubules within the cell.3192

They are found in the centrosomes, and the spindle fibers made out of microtubules radiate out from the centrioles and then separate the chromosomes during mitosis and miosis.3196

Remember that microtubules are very important for motility of the cell.3210

The second structure that is composed of microtubules is flagella. Flagella allow cells to have motility.3214

They move back and for by an angulating motion. Again, an example would be the motility of sperm cells.3225

Third, cilia, this also allows for motility. They are shorter than flagella, and there is often many per cell.3233

They are especially effective in moving fluid, so they are found in areas like the respiratory tract.3243

Also, you should be aware that there is another type of cilia called primary cilia. These are found in almost every cell in invertebrates.3250

However, there is only one per cell. The important thing is that these are non-modal.3261

They are different in regular cilia, and that they are non-modal, and they have different functions.3266

The primary cilia actually function for sensory reception and signalling pathways. They also have a different microtubule arrangement than that of cilia and flagella.3273

Centrioles and spindle fibers, flagella, cilia and also primary cilia, which have different functions and structure, they are still composed of microtubules.3294

What are microfilaments composed of? They are composed of actin, and remember that actin interacts with myosin to allow for cell motility.3304

And now, we are asked to give two examples in which microfilaments are involve in cell motility.3314

One of these is muscle contraction. The interaction with actin and myosin allows for muscle contraction.3321

Second would be cytoplasmic streaming. Cytoplasmic streaming is found in plant cells and fungal cells.3330

And let's say in a plant cell, what will happen is the cytoplasm will actually flow around in a circular pattern.3342

And you can think of it as analogous to stirring up something when you are cooking, and the purpose is actually to move things around.3350

This allows for nutrients to get where they needed for exchange of materials between the organelles.3358

Instead of the cytoplasm just sitting there, by, sort of, stirring it up, moving it around, it allows for exchange of materials.3364

Cytoplasmic streaming in plants and fungi are the result of microfilaments.3372

A couple more, I mentioned that amoebas move using pseudopods, and these are the result of microfilaments.3378

That is what allows the pseudopods to move.3390

Finally, cell division, the cleavage furrow.3394

When two cells or excuse me one cell is preparing to divide into two, it forms this furrow, and then, separates of into two cells.3400

Example four: why do some antibiotics that target bacterial cells also affect mitochondria and chloroplast?3416

It is true that there are antibiotics that are meant to just target bacterial cells, but they are also been shown in the lab to affect mitochondria and chloroplast.3423

And the reason for that is because chloroplast and mitochondria have structural similarities to bacterial cells.3435

So, similarities between bacteria and mitochondria and chloroplast- that would be a reason, for example the ribosomes.3446

If an antibiotic is targeting bacterial ribosomes, these are 70S ribosomes, so I would expect the antibiotic to affect the bacteria and the mitochondria and chloroplast.3468

But it is going to leave the other ribosomes in the eukaryotic cell alone because those have a different structure. They are 80S.3479

Other similarities, remember, are the DNA. It is circular.3486

The DNA of mitochondria, bacteria and chloroplast are all circular.3495

Size: mitochondria and chloroplast are smaller. Eukaryotic cells are larger.3501

These similarities could cause an antibiotic to affect all three cell types.3507

How is this relevant to the endosymbiotic theory of eukaryotic origin?3514

Well, the endosymbiotic theory states that organelles from the eukaryotic cell are results of a relationship in the engulfment of smaller aerobic bacteria by larger anaerobic bacteria.3518

There is a larger prokaryotic anaerobic cell. It engulfed a smaller prokaryotic aerobic cell.3536

And eventually, over time, evolution, this became a eukaryotic cell, and the smaller bacterial cell became mitochondria, chloroplast, organelles within the cell.3545

And the fact that mitochondria and chloroplast are similar to bacterial cells, it provides support for this endosymbiosis theory of eukaryotic origin.3560

Thanks for visiting Educator.com, and that concludes this lecture on subcellular structure.3572

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