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Raffi Hovasapian

Raffi Hovasapian

Fatty Acid Catabolism II

Slide Duration:

Table of Contents

I. Preliminaries on Aqueous Chemistry
Aqueous Solutions & Concentration

39m 57s

Intro
0:00
Aqueous Solutions and Concentration
0:46
Definition of Solution
1:28
Example: Sugar Dissolved in Water
2:19
Example: Salt Dissolved in Water
3:04
A Solute Does Not Have to Be a Solid
3:37
A Solvent Does Not Have to Be a Liquid
5:02
Covalent Compounds
6:55
Ionic Compounds
7:39
Example: Table Sugar
9:12
Example: MgCl₂
10:40
Expressing Concentration: Molarity
13:42
Example 1
14:47
Example 1: Question
14:50
Example 1: Solution
15:40
Another Way to Express Concentration
22:01
Example 2
24:00
Example 2: Question
24:01
Example 2: Solution
24:49
Some Other Ways of Expressing Concentration
27:52
Example 3
29:30
Example 3: Question
29:31
Example 3: Solution
31:02
Dilution & Osmotic Pressure

38m 53s

Intro
0:00
Dilution
0:45
Definition of Dilution
0:46
Example 1: Question
2:08
Example 1: Basic Dilution Equation
4:20
Example 1: Solution
5:31
Example 2: Alternative Approach
12:05
Osmotic Pressure
14:34
Colligative Properties
15:02
Recall: Covalent Compounds and Soluble Ionic Compounds
17:24
Properties of Pure Water
19:42
Addition of a Solute
21:56
Osmotic Pressure: Conceptual Example
24:00
Equation for Osmotic Pressure
29:30
Example of 'i'
31:38
Example 3
32:50
More on Osmosis

29m 1s

Intro
0:00
More on Osmosis
1:25
Osmotic Pressure
1:26
Example 1: Molar Mass of Protein
5:25
Definition, Equation, and Unit of Osmolarity
13:13
Example 2: Osmolarity
15:19
Isotonic, Hypertonic, and Hypotonic
20:20
Example 3
22:20
More on Isotonic, Hypertonic, and Hypotonic
26:14
Osmosis vs. Osmotic Pressure
27:56
Acids & Bases

39m 11s

Intro
0:00
Acids and Bases
1:16
Let's Begin With H₂O
1:17
P-Scale
4:22
Example 1
6:39
pH
9:43
Strong Acids
11:10
Strong Bases
13:52
Weak Acids & Bases Overview
14:32
Weak Acids
15:49
Example 2: Phosphoric Acid
19:30
Weak Bases
24:50
Weak Base Produces Hydroxide Indirectly
25:41
Example 3: Pyridine
29:07
Acid Form and Base Form
32:02
Acid Reaction
35:50
Base Reaction
36:27
Ka, Kb, and Kw
37:14
Titrations and Buffers

41m 33s

Intro
0:00
Titrations
0:27
Weak Acid
0:28
Rearranging the Ka Equation
1:45
Henderson-Hasselbalch Equation
3:52
Fundamental Reaction of Acids and Bases
5:36
The Idea Behind a Titration
6:27
Let's Look at an Acetic Acid Solution
8:44
Titration Curve
17:00
Acetate
23:57
Buffers
26:57
Introduction to Buffers
26:58
What is a Buffer?
29:40
Titration Curve & Buffer Region
31:44
How a Buffer Works: Adding OH⁻
34:44
How a Buffer Works: Adding H⁺
35:58
Phosphate Buffer System
38:02
Example Problems with Acids, Bases & Buffers

44m 19s

Intro
0:00
Example 1
1:21
Example 1: Properties of Glycine
1:22
Example 1: Part A
3:40
Example 1: Part B
4:40
Example 2
9:02
Example 2: Question
9:03
Example 2: Total Phosphate Concentration
12:23
Example 2: Final Solution
17:10
Example 3
19:34
Example 3: Question
19:35
Example 3: pH Before
22:18
Example 3: pH After
24:24
Example 3: New pH
27:54
Example 4
30:00
Example 4: Question
30:01
Example 4: Equilibria
32:52
Example 4: 1st Reaction
38:04
Example 4: 2nd Reaction
39:53
Example 4: Final Solution
41:33
Hydrolysis & Condensation Reactions

18m 45s

Intro
0:00
Hydrolysis and Condensation Reactions
0:50
Hydrolysis
0:51
Condensation
2:42
Example 1: Hydrolysis of Ethyl Acetate
4:52
Example 2: Condensation of Acetic Acid with Ethanol
8:42
Example 3
11:18
Example 4: Formation & Hydrolysis of a Peptide Bond Between the Amino Acids Alanine & Serine
14:56
II. Amino Acids & Proteins: Primary Structure
Amino Acids

38m 19s

Intro
0:00
Amino Acids
0:17
Proteins & Amino Acids
0:18
Difference Between Amino Acids
4:20
α-Carbon
7:08
Configuration in Biochemistry
10:43
L-Glyceraldehyde & Fischer Projection
12:32
D-Glyceraldehyde & Fischer Projection
15:31
Amino Acids in Biological Proteins are the L Enantiomer
16:50
L-Amino Acid
18:04
L-Amino Acids Correspond to S-Enantiomers in the RS System
20:10
Classification of Amino Acids
22:53
Amino Acids With Non-Polar R Groups
26:45
Glycine
27:00
Alanine
27:48
Valine
28:15
Leucine
28:58
Proline
31:08
Isoleucine
32:42
Methionine
33:43
Amino Acids With Aromatic R Groups
34:33
Phenylalanine
35:26
Tyrosine
36:02
Tryptophan
36:32
Amino Acids, Continued

27m 14s

Intro
0:00
Amino Acids With Positively Charged R Groups
0:16
Lysine
0:52
Arginine
1:55
Histidine
3:15
Amino Acids With Negatively Charged R Groups
6:28
Aspartate
6:58
Glutamate
8:11
Amino Acids With Uncharged, but Polar R Groups
8:50
Serine
8:51
Threonine
10:21
Cysteine
11:06
Asparagine
11:35
Glutamine
12:44
More on Amino Acids
14:18
Cysteine Dimerizes to Form Cystine
14:53
Tryptophan, Tyrosine, and Phenylalanine
19:07
Other Amino Acids
20:53
Other Amino Acids: Hydroxy Lysine
22:34
Other Amino Acids: r-Carboxy Glutamate
25:37
Acid/Base Behavior of Amino Acids

48m 28s

Intro
0:00
Acid/Base Behavior of Amino Acids
0:27
Acid/Base Behavior of Amino Acids
0:28
Let's Look at Alanine
1:57
Titration of Acidic Solution of Alanine with a Strong Base
2:51
Amphoteric Amino Acids
13:24
Zwitterion & Isoelectric Point
16:42
Some Amino Acids Have 3 Ionizable Groups
20:35
Example: Aspartate
24:44
Example: Tyrosine
28:50
Rule of Thumb
33:04
Basis for the Rule
35:59
Example: Describe the Degree of Protonation for Each Ionizable Group
38:46
Histidine is Special
44:58
Peptides & Proteins

45m 18s

Intro
0:00
Peptides and Proteins
0:15
Introduction to Peptides and Proteins
0:16
Formation of a Peptide Bond: The Bond Between 2 Amino Acids
1:44
Equilibrium
7:53
Example 1: Build the Following Tripeptide Ala-Tyr-Ile
9:48
Example 1: Shape Structure
15:43
Example 1: Line Structure
17:11
Peptides Bonds
20:08
Terms We'll Be Using Interchangeably
23:14
Biological Activity & Size of a Peptide
24:58
Multi-Subunit Proteins
30:08
Proteins and Prosthetic Groups
32:13
Carbonic Anhydrase
37:35
Primary, Secondary, Tertiary, and Quaternary Structure of Proteins
40:26
Amino Acid Sequencing of a Peptide Chain

42m 47s

Intro
0:00
Amino Acid Sequencing of a Peptide Chain
0:30
Amino Acid Sequence and Its Structure
0:31
Edman Degradation: Overview
2:57
Edman Degradation: Reaction - Part 1
4:58
Edman Degradation: Reaction - Part 2
10:28
Edman Degradation: Reaction - Part 3
13:51
Mechanism Step 1: PTC (Phenylthiocarbamyl) Formation
19:01
Mechanism Step 2: Ring Formation & Peptide Bond Cleavage
23:03
Example: Write Out the Edman Degradation for the Tripeptide Ala-Tyr-Ser
30:29
Step 1
30:30
Step 2
34:21
Step 3
36:56
Step 4
38:28
Step 5
39:24
Step 6
40:44
Sequencing Larger Peptides & Proteins

1h 2m 33s

Intro
0:00
Sequencing Larger Peptides and Proteins
0:28
Identifying the N-Terminal Amino Acids With the Reagent Fluorodinitrobenzene (FDNB)
0:29
Sequencing Longer Peptides & Proteins Overview
5:54
Breaking Peptide Bond: Proteases and Chemicals
8:16
Some Enzymes/Chemicals Used for Fragmentation: Trypsin
11:14
Some Enzymes/Chemicals Used for Fragmentation: Chymotrypsin
13:02
Some Enzymes/Chemicals Used for Fragmentation: Cyanogen Bromide
13:28
Some Enzymes/Chemicals Used for Fragmentation: Pepsin
13:44
Cleavage Location
14:04
Example: Chymotrypsin
16:44
Example: Pepsin
18:17
More on Sequencing Larger Peptides and Proteins
19:29
Breaking Disulfide Bonds: Performic Acid
26:08
Breaking Disulfide Bonds: Dithiothreitol Followed by Iodoacetate
31:04
Example: Sequencing Larger Peptides and Proteins
37:03
Part 1 - Breaking Disulfide Bonds, Hydrolysis and Separation
37:04
Part 2 - N-Terminal Identification
44:16
Part 3 - Sequencing Using Pepsin
46:43
Part 4 - Sequencing Using Cyanogen Bromide
52:02
Part 5 - Final Sequence
56:48
Peptide Synthesis (Merrifield Process)

49m 12s

Intro
0:00
Peptide Synthesis (Merrifield Process)
0:31
Introduction to Synthesizing Peptides
0:32
Merrifield Peptide Synthesis: General Scheme
3:03
So What Do We Do?
6:07
Synthesis of Protein in the Body Vs. The Merrifield Process
7:40
Example: Synthesis of Ala-Gly-Ser
9:21
Synthesis of Ala-Gly-Ser: Reactions Overview
11:41
Synthesis of Ala-Gly-Ser: Reaction 1
19:34
Synthesis of Ala-Gly-Ser: Reaction 2
24:34
Synthesis of Ala-Gly-Ser: Reaction 3
27:34
Synthesis of Ala-Gly-Ser: Reaction 4 & 4a
28:48
Synthesis of Ala-Gly-Ser: Reaction 5
33:38
Synthesis of Ala-Gly-Ser: Reaction 6
36:45
Synthesis of Ala-Gly-Ser: Reaction 7 & 7a
37:44
Synthesis of Ala-Gly-Ser: Reaction 8
39:47
Synthesis of Ala-Gly-Ser: Reaction 9 & 10
43:23
Chromatography: Eluent, Stationary Phase, and Eluate
45:55
More Examples with Amino Acids & Peptides

54m 31s

Intro
0:00
Example 1
0:22
Data
0:23
Part A: What is the pI of Serine & Draw the Correct Structure
2:11
Part B: How Many mL of NaOH Solution Have Been Added at This Point (pI)?
5:27
Part C: At What pH is the Average Charge on Serine
10:50
Part D: Draw the Titration Curve for This Situation
14:50
Part E: The 10 mL of NaOH Added to the Solution at the pI is How Many Equivalents?
17:35
Part F: Serine Buffer Solution
20:22
Example 2
23:04
Data
23:05
Part A: Calculate the Minimum Molar Mass of the Protein
25:12
Part B: How Many Tyr Residues in this Protein?
28:34
Example 3
30:08
Question
30:09
Solution
34:30
Example 4
48:46
Question
48:47
Solution
49:50
III. Proteins: Secondary, Tertiary, and Quaternary Structure
Alpha Helix & Beta Conformation

50m 52s

Intro
0:00
Alpha Helix and Beta Conformation
0:28
Protein Structure Overview
0:29
Weak interactions Among the Amino Acid in the Peptide Chain
2:11
Two Principals of Folding Patterns
4:56
Peptide Bond
7:00
Peptide Bond: Resonance
9:46
Peptide Bond: φ Bond & ψ Bond
11:22
Secondary Structure
15:08
α-Helix Folding Pattern
17:28
Illustration 1: α-Helix Folding Pattern
19:22
Illustration 2: α-Helix Folding Pattern
21:39
β-Sheet
25:16
β-Conformation
26:04
Parallel & Anti-parallel
28:44
Parallel β-Conformation Arrangement of the Peptide Chain
30:12
Putting Together a Parallel Peptide Chain
35:16
Anti-Parallel β-Conformation Arrangement
37:42
Tertiary Structure
45:03
Quaternary Structure
45:52
Illustration 3: Myoglobin Tertiary Structure & Hemoglobin Quaternary Structure
47:13
Final Words on Alpha Helix and Beta Conformation
48:34
IV. Proteins: Function
Protein Function I: Ligand Binding & Myoglobin

51m 36s

Intro
0:00
Protein Function I: Ligand Binding & Myoglobin
0:30
Ligand
1:02
Binding Site
2:06
Proteins are Not Static or Fixed
3:36
Multi-Subunit Proteins
5:46
O₂ as a Ligand
7:21
Myoglobin, Protoporphyrin IX, Fe ²⁺, and O₂
12:54
Protoporphyrin Illustration
14:25
Myoglobin With a Heme Group Illustration
17:02
Fe²⁺ has 6 Coordination Sites & Binds O₂
18:10
Heme
19:44
Myoglobin Overview
22:40
Myoglobin and O₂ Interaction
23:34
Keq or Ka & The Measure of Protein's Affinity for Its Ligand
26:46
Defining α: Fraction of Binding Sites Occupied
32:52
Graph: α vs. [L]
37:33
For The Special Case of α = 0.5
39:01
Association Constant & Dissociation Constant
43:54
α & Kd
45:15
Myoglobin's Binding of O₂
48:20
Protein Function II: Hemoglobin

1h 3m 36s

Intro
0:00
Protein Function II: Hemoglobin
0:14
Hemoglobin Overview
0:15
Hemoglobin & Its 4 Subunits
1:22
α and β Interactions
5:18
Two Major Conformations of Hb: T State (Tense) & R State (Relaxed)
8:06
Transition From The T State to R State
12:03
Binding of Hemoglobins & O₂
14:02
Binding Curve
18:32
Hemoglobin in the Lung
27:28
Signoid Curve
30:13
Cooperative Binding
32:25
Hemoglobin is an Allosteric Protein
34:26
Homotropic Allostery
36:18
Describing Cooperative Binding Quantitatively
38:06
Deriving The Hill Equation
41:52
Graphing the Hill Equation
44:43
The Slope and Degree of Cooperation
46:25
The Hill Coefficient
49:48
Hill Coefficient = 1
51:08
Hill Coefficient < 1
55:55
Where the Graph Hits the x-axis
56:11
Graph for Hemoglobin
58:02
Protein Function III: More on Hemoglobin

1h 7m 16s

Intro
0:00
Protein Function III: More on Hemoglobin
0:11
Two Models for Cooperative Binding: MWC & Sequential Model
0:12
MWC Model
1:31
Hemoglobin Subunits
3:32
Sequential Model
8:00
Hemoglobin Transports H⁺ & CO₂
17:23
Binding Sites of H⁺ and CO₂
19:36
CO₂ is Converted to Bicarbonate
23:28
Production of H⁺ & CO₂ in Tissues
27:28
H⁺ & CO₂ Binding are Inversely Related to O₂ Binding
28:31
The H⁺ Bohr Effect: His¹⁴⁶ Residue on the β Subunits
33:31
Heterotropic Allosteric Regulation of O₂ Binding by 2,3-Biphosphoglycerate (2,3 BPG)
39:53
Binding Curve for 2,3 BPG
56:21
V. Enzymes
Enzymes I

41m 38s

Intro
0:00
Enzymes I
0:38
Enzymes Overview
0:39
Cofactor
4:38
Holoenzyme
5:52
Apoenzyme
6:40
Riboflavin, FAD, Pyridoxine, Pyridoxal Phosphate Structures
7:28
Carbonic Anhydrase
8:45
Classification of Enzymes
9:55
Example: EC 1.1.1.1
13:04
Reaction of Oxidoreductases
16:23
Enzymes: Catalysts, Active Site, and Substrate
18:28
Illustration of Enzymes, Substrate, and Active Site
27:22
Catalysts & Activation Energies
29:57
Intermediates
36:00
Enzymes II

44m 2s

Intro
0:00
Enzymes II: Transitions State, Binding Energy, & Induced Fit
0:18
Enzymes 'Fitting' Well With The Transition State
0:20
Example Reaction: Breaking of a Stick
3:40
Another Energy Diagram
8:20
Binding Energy
9:48
Enzymes Specificity
11:03
Key Point: Optimal Interactions Between Substrate & Enzymes
15:15
Induced Fit
16:25
Illustrations: Induced Fit
20:58
Enzymes II: Catalytic Mechanisms
22:17
General Acid/Base Catalysis
23:56
Acid Form & Base Form of Amino Acid: Glu &Asp
25:26
Acid Form & Base Form of Amino Acid: Lys & Arg
26:30
Acid Form & Base Form of Amino Acid: Cys
26:51
Acid Form & Base Form of Amino Acid: His
27:30
Acid Form & Base Form of Amino Acid: Ser
28:16
Acid Form & Base Form of Amino Acid: Tyr
28:30
Example: Phosphohexose Isomerase
29:20
Covalent Catalysis
34:19
Example: Glyceraldehyde 3-Phosphate Dehydrogenase
35:34
Metal Ion Catalysis: Isocitrate Dehydrogenase
38:45
Function of Mn²⁺
42:15
Enzymes III: Kinetics

56m 40s

Intro
0:00
Enzymes III: Kinetics
1:40
Rate of an Enzyme-Catalyzed Reaction & Substrate Concentration
1:41
Graph: Substrate Concentration vs. Reaction Rate
10:43
Rate At Low and High Substrate Concentration
14:26
Michaelis & Menten Kinetics
20:16
More On Rate & Concentration of Substrate
22:46
Steady-State Assumption
26:02
Rate is Determined by How Fast ES Breaks Down to Product
31:36
Total Enzyme Concentration: [Et] = [E] + [ES]
35:35
Rate of ES Formation
36:44
Rate of ES Breakdown
38:40
Measuring Concentration of Enzyme-Substrate Complex
41:19
Measuring Initial & Maximum Velocity
43:43
Michaelis & Menten Equation
46:44
What Happens When V₀ = (1/2) Vmax?
49:12
When [S] << Km
53:32
When [S] >> Km
54:44
Enzymes IV: Lineweaver-Burk Plots

20m 37s

Intro
0:00
Enzymes IV: Lineweaver-Burk Plots
0:45
Deriving The Lineweaver-Burk Equation
0:46
Lineweaver-Burk Plots
3:55
Example 1: Carboxypeptidase A
8:00
More on Km, Vmax, and Enzyme-catalyzed Reaction
15:54
Enzymes V: Enzyme Inhibition

51m 37s

Intro
0:00
Enzymes V: Enzyme Inhibition Overview
0:42
Enzyme Inhibitors Overview
0:43
Classes of Inhibitors
2:32
Competitive Inhibition
3:08
Competitive Inhibition
3:09
Michaelis & Menten Equation in the Presence of a Competitive Inhibitor
7:40
Double-Reciprocal Version of the Michaelis & Menten Equation
14:48
Competitive Inhibition Graph
16:37
Uncompetitive Inhibition
19:23
Uncompetitive Inhibitor
19:24
Michaelis & Menten Equation for Uncompetitive Inhibition
22:10
The Lineweaver-Burk Equation for Uncompetitive Inhibition
26:04
Uncompetitive Inhibition Graph
27:42
Mixed Inhibition
30:30
Mixed Inhibitor
30:31
Double-Reciprocal Version of the Equation
33:34
The Lineweaver-Burk Plots for Mixed Inhibition
35:02
Summary of Reversible Inhibitor Behavior
38:00
Summary of Reversible Inhibitor Behavior
38:01
Note: Non-Competitive Inhibition
42:22
Irreversible Inhibition
45:15
Irreversible Inhibition
45:16
Penicillin & Transpeptidase Enzyme
46:50
Enzymes VI: Regulatory Enzymes

51m 23s

Intro
0:00
Enzymes VI: Regulatory Enzymes
0:45
Regulatory Enzymes Overview
0:46
Example: Glycolysis
2:27
Allosteric Regulatory Enzyme
9:19
Covalent Modification
13:08
Two Other Regulatory Processes
16:28
Allosteric Regulation
20:58
Feedback Inhibition
25:12
Feedback Inhibition Example: L-Threonine → L-Isoleucine
26:03
Covalent Modification
27:26
Covalent Modulators: -PO₃²⁻
29:30
Protein Kinases
31:59
Protein Phosphatases
32:47
Addition/Removal of -PO₃²⁻ and the Effect on Regulatory Enzyme
33:36
Phosphorylation Sites of a Regulatory Enzyme
38:38
Proteolytic Cleavage
41:48
Zymogens: Chymotrypsin & Trypsin
43:58
Enzymes That Use More Than One Regulatory Process: Bacterial Glutamine Synthetase
48:59
Why The Complexity?
50:27
Enzymes VII: Km & Kcat

54m 49s

Intro
0:00
Km
1:48
Recall the Michaelis–Menten Equation
1:49
Km & Enzyme's Affinity
6:18
Rate Forward, Rate Backward, and Equilibrium Constant
11:08
When an Enzyme's Affinity for Its Substrate is High
14:17
More on Km & Enzyme Affinity
17:29
The Measure of Km Under Michaelis–Menten kinetic
23:19
Kcat (First-order Rate Constant or Catalytic Rate Constant)
24:10
Kcat: Definition
24:11
Kcat & The Michaelis–Menten Postulate
25:18
Finding Vmax and [Et}
27:27
Units for Vmax and Kcat
28:26
Kcat: Turnover Number
28:55
Michaelis–Menten Equation
32:12
Km & Kcat
36:37
Second Order Rate Equation
36:38
(Kcat)/(Km): Overview
39:22
High (Kcat)/(Km)
40:20
Low (Kcat)/(Km)
43:16
Practical Big Picture
46:28
Upper Limit to (Kcat)/(Km)
48:56
More On Kcat and Km
49:26
VI. Carbohydrates
Monosaccharides

1h 17m 46s

Intro
0:00
Monosaccharides
1:49
Carbohydrates Overview
1:50
Three Major Classes of Carbohydrates
4:48
Definition of Monosaccharides
5:46
Examples of Monosaccharides: Aldoses
7:06
D-Glyceraldehyde
7:39
D-Erythrose
9:00
D-Ribose
10:10
D-Glucose
11:20
Observation: Aldehyde Group
11:54
Observation: Carbonyl 'C'
12:30
Observation: D & L Naming System
12:54
Examples of Monosaccharides: Ketose
16:54
Dihydroxy Acetone
17:28
D-Erythrulose
18:30
D-Ribulose
19:49
D-Fructose
21:10
D-Glucose Comparison
23:18
More information of Ketoses
24:50
Let's Look Closer at D-Glucoses
25:50
Let's Look At All the D-Hexose Stereoisomers
31:22
D-Allose
32:20
D-Altrose
33:01
D-Glucose
33:39
D-Gulose
35:00
D-Mannose
35:40
D-Idose
36:42
D-Galactose
37:14
D-Talose
37:42
Epimer
40:05
Definition of Epimer
40:06
Example of Epimer: D-Glucose, D-Mannose, and D-Galactose
40:57
Hemiacetal or Hemiketal
44:36
Hemiacetal/Hemiketal Overview
45:00
Ring Formation of the α and β Configurations of D-Glucose
50:52
Ring Formation of the α and β Configurations of Fructose
1:01:39
Haworth Projection
1:07:34
Pyranose & Furanose Overview
1:07:38
Haworth Projection: Pyranoses
1:09:30
Haworth Projection: Furanose
1:14:56
Hexose Derivatives & Reducing Sugars

37m 6s

Intro
0:00
Hexose Derivatives
0:15
Point of Clarification: Forming a Cyclic Sugar From a Linear Sugar
0:16
Let's Recall the α and β Anomers of Glucose
8:42
α-Glucose
10:54
Hexose Derivatives that Play Key Roles in Physiology Progression
17:38
β-Glucose
18:24
β-Glucosamine
18:48
N-Acetyl-β-Glucosamine
20:14
β-Glucose-6-Phosphate
22:22
D-Gluconate
24:10
Glucono-δ-Lactone
26:33
Reducing Sugars
29:50
Reducing Sugars Overview
29:51
Reducing Sugars Example: β-Galactose
32:36
Disaccharides

43m 32s

Intro
0:00
Disaccharides
0:15
Disaccharides Overview
0:19
Examples of Disaccharides & How to Name Them
2:49
Disaccharides Trehalose Overview
15:46
Disaccharides Trehalose: Flip
20:52
Disaccharides Trehalose: Spin
28:36
Example: Draw the Structure
33:12
Polysaccharides

39m 25s

Intro
0:00
Recap Example: Draw the Structure of Gal(α1↔β1)Man
0:38
Polysaccharides
9:46
Polysaccharides Overview
9:50
Homopolysaccharide
13:12
Heteropolysaccharide
13:47
Homopolysaccharide as Fuel Storage
16:23
Starch Has Two Types of Glucose Polymer: Amylose
17:10
Starch Has Two Types of Glucose Polymer: Amylopectin
18:04
Polysaccharides: Reducing End & Non-Reducing End
19:30
Glycogen
20:06
Examples: Structures of Polysaccharides
21:42
Let's Draw an (α1→4) & (α1→6) of Amylopectin by Hand.
28:14
More on Glycogen
31:17
Glycogen, Concentration, & The Concept of Osmolarity
35:16
Polysaccharides, Part 2

44m 15s

Intro
0:00
Polysaccharides
0:17
Example: Cellulose
0:34
Glycoside Bond
7:25
Example Illustrations
12:30
Glycosaminoglycans Part 1
15:55
Glycosaminoglycans Part 2
18:34
Glycosaminoglycans & Sulfate Attachments
22:42
β-D-N-Acetylglucosamine
24:49
β-D-N-AcetylGalactosamine
25:42
β-D-Glucuronate
26:44
β-L-Iduronate
27:54
More on Sulfate Attachments
29:49
Hylarunic Acid
32:00
Hyaluronates
39:32
Other Glycosaminoglycans
40:46
Glycoconjugates

44m 23s

Intro
0:00
Glycoconjugates
0:24
Overview
0:25
Proteoglycan
2:53
Glycoprotein
5:20
Glycolipid
7:25
Proteoglycan vs. Glycoprotein
8:15
Cell Surface Diagram
11:17
Proteoglycan Common Structure
14:24
Example: Chondroitin-4-Sulfate
15:06
Glycoproteins
19:50
The Monomers that Commonly Show Up in The Oligo Portions of Glycoproteins
28:02
N-Acetylneuraminic Acid
31:17
L-Furose
32:37
Example of an N-Linked Oligosaccharide
33:21
Cell Membrane Structure
36:35
Glycolipids & Lipopolysaccharide
37:22
Structure Example
41:28
More Example Problems with Carbohydrates

40m 22s

Intro
0:00
Example 1
1:09
Example 2
2:34
Example 3
5:12
Example 4
16:19
Question
16:20
Solution
17:25
Example 5
24:18
Question
24:19
Structure of 2,3-Di-O-Methylglucose
26:47
Part A
28:11
Part B
33:46
VII. Lipids
Fatty Acids & Triacylglycerols

54m 55s

Intro
0:00
Fatty Acids
0:32
Lipids Overview
0:34
Introduction to Fatty Acid
3:18
Saturated Fatty Acid
6:13
Unsaturated or Polyunsaturated Fatty Acid
7:07
Saturated Fatty Acid Example
7:46
Unsaturated Fatty Acid Example
9:06
Notation Example: Chain Length, Degree of Unsaturation, & Double Bonds Location of Fatty Acid
11:56
Example 1: Draw the Structure
16:18
Example 2: Give the Shorthand for cis,cis-5,8-Hexadecadienoic Acid
20:12
Example 3
23:12
Solubility of Fatty Acids
25:45
Melting Points of Fatty Acids
29:40
Triacylglycerols
34:13
Definition of Triacylglycerols
34:14
Structure of Triacylglycerols
35:08
Example: Triacylglycerols
40:23
Recall Ester Formation
43:57
The Body's Primary Fuel-Reserves
47:22
Two Primary Advantages to Storing Energy as Triacylglycerols Instead of Glycogen: Number 1
49:24
Two Primary Advantages to Storing Energy as Triacylglycerols Instead of Glycogen: Number 2
51:54
Membrane Lipids

38m 51s

Intro
0:00
Membrane Lipids
0:26
Definition of Membrane Lipids
0:27
Five Major Classes of Membrane Lipids
2:38
Glycerophospholipids
5:04
Glycerophospholipids Overview
5:05
The X Group
8:05
Example: Phosphatidyl Ethanolamine
10:51
Example: Phosphatidyl Choline
13:34
Phosphatidyl Serine
15:16
Head Groups
16:50
Ether Linkages Instead of Ester Linkages
20:05
Galactolipids
23:39
Galactolipids Overview
23:40
Monogalactosyldiacylglycerol: MGDG
25:17
Digalactosyldiacylglycerol: DGDG
28:13
Structure Examples 1: Lipid Bilayer
31:35
Structure Examples 2: Cross Section of a Cell
34:56
Structure Examples 3: MGDG & DGDG
36:28
Membrane Lipids, Part 2

38m 20s

Intro
0:00
Sphingolipids
0:11
Sphingolipid Overview
0:12
Sphingosine Structure
1:42
Ceramide
3:56
Subclasses of Sphingolipids Overview
6:00
Subclasses of Sphingolipids: Sphingomyelins
7:53
Sphingomyelins
7:54
Subclasses of Sphingolipids: Glycosphingolipid
12:47
Glycosphingolipid Overview
12:48
Cerebrosides & Globosides Overview
14:33
Example: Cerebrosides
15:43
Example: Globosides
17:14
Subclasses of Sphingolipids: Gangliosides
19:07
Gangliosides
19:08
Medical Application: Tay-Sachs Disease
23:34
Sterols
30:45
Sterols: Basic Structure
30:46
Important Example: Cholesterol
32:01
Structures Example
34:13
The Biologically Active Lipids

48m 36s

Intro
0:00
The Biologically Active Lipids
0:44
Phosphatidyl Inositol Structure
0:45
Phosphatidyl Inositol Reaction
3:24
Image Example
12:49
Eicosanoids
14:12
Arachidonic Acid & Membrane Lipid Containing Arachidonic Acid
18:41
Three Classes of Eicosanoids
20:42
Overall Structures
21:38
Prostagladins
22:56
Thromboxane
27:19
Leukotrienes
30:19
More On The Biologically Active Lipids
33:34
Steroid Hormones
33:35
Fat Soluble Vitamins
38:25
Vitamin D₃
40:40
Vitamin A
43:17
Vitamin E
45:12
Vitamin K
47:17
VIII. Energy & Biological Systems (Bioenergetics)
Thermodynamics, Free Energy & Equilibrium

45m 51s

Intro
0:00
Thermodynamics, Free Energy and Equilibrium
1:03
Reaction: Glucose + Pi → Glucose 6-Phosphate
1:50
Thermodynamics & Spontaneous Processes
3:31
In Going From Reactants → Product, a Reaction Wants to Release Heat
6:30
A Reaction Wants to Become More Disordered
9:10
∆H < 0
10:30
∆H > 0
10:57
∆S > 0
11:23
∆S <0
11:56
∆G = ∆H - T∆S at Constant Pressure
12:15
Gibbs Free Energy
15:00
∆G < 0
16:49
∆G > 0
17:07
Reference Frame For Thermodynamics Measurements
17:57
More On BioChemistry Standard
22:36
Spontaneity
25:36
Keq
31:45
Example: Glucose + Pi → Glucose 6-Phosphate
34:14
Example Problem 1
40:25
Question
40:26
Solution
41:12
More on Thermodynamics & Free Energy

37m 6s

Intro
0:00
More on Thermodynamics & Free Energy
0:16
Calculating ∆G Under Standard Conditions
0:17
Calculating ∆G Under Physiological Conditions
2:05
∆G < 0
5:39
∆G = 0
7:03
Reaction Moving Forward Spontaneously
8:00
∆G & The Maximum Theoretical Amount of Free Energy Available
10:36
Example Problem 1
13:11
Reactions That Have Species in Common
17:48
Example Problem 2: Part 1
20:10
Example Problem 2: Part 2- Enzyme Hexokinase & Coupling
25:08
Example Problem 2: Part 3
30:34
Recap
34:45
ATP & Other High-Energy Compounds

44m 32s

Intro
0:00
ATP & Other High-Energy Compounds
0:10
Endergonic Reaction Coupled With Exergonic Reaction
0:11
Major Theme In Metabolism
6:56
Why the ∆G°' for ATP Hydrolysis is Large & Negative
12:24
∆G°' for ATP Hydrolysis
12:25
Reason 1: Electrostatic Repulsion
14:24
Reason 2: Pi & Resonance Forms
15:33
Reason 3: Concentrations of ADP & Pi
17:32
ATP & Other High-Energy Compounds Cont'd
18:48
More On ∆G°' & Hydrolysis
18:49
Other Compounds That Have Large Negative ∆G°' of Hydrolysis: Phosphoenol Pyruvate (PEP)
25:14
Enzyme Pyruvate Kinase
30:36
Another High Energy Molecule: 1,3 Biphosphoglycerate
36:17
Another High Energy Molecule: Phophocreatine
39:41
Phosphoryl Group Transfers

30m 8s

Intro
0:00
Phosphoryl Group Transfer
0:27
Phosphoryl Group Transfer Overview
0:28
Example: Glutamate → Glutamine Part 1
7:11
Example: Glutamate → Glutamine Part 2
13:29
ATP Not Only Transfers Phosphoryl, But Also Pyrophosphoryl & Adenylyl Groups
17:03
Attack At The γ Phosphorous Transfers a Phosphoryl
19:02
Attack At The β Phosphorous Gives Pyrophosphoryl
22:44
Oxidation-Reduction Reactions

49m 46s

Intro
0:00
Oxidation-Reduction Reactions
1:32
Redox Reactions
1:33
Example 1: Mg + Al³⁺ → Mg²⁺ + Al
3:49
Reduction Potential Definition
10:47
Reduction Potential Example
13:38
Organic Example
22:23
Review: How To Find The Oxidation States For Carbon
24:15
Examples: Oxidation States For Carbon
27:45
Example 1: Oxidation States For Carbon
27:46
Example 2: Oxidation States For Carbon
28:36
Example 3: Oxidation States For Carbon
29:18
Example 4: Oxidation States For Carbon
29:44
Example 5: Oxidation States For Carbon
30:10
Example 6: Oxidation States For Carbon
30:40
Example 7: Oxidation States For Carbon
31:20
Example 8: Oxidation States For Carbon
32:10
Example 9: Oxidation States For Carbon
32:52
Oxidation-Reduction Reactions, cont'd
35:22
More On Reduction Potential
35:28
Lets' Start With ∆G = ∆G°' + RTlnQ
38:29
Example: Oxidation Reduction Reactions
41:42
More On Oxidation-Reduction Reactions

56m 34s

Intro
0:00
More On Oxidation-Reduction Reactions
0:10
Example 1: What If the Concentrations Are Not Standard?
0:11
Alternate Procedure That Uses The 1/2 Reactions Individually
8:57
Universal Electron Carriers in Aqueous Medium: NAD+ & NADH
15:12
The Others Are…
19:22
NAD+ & NADP Coenzymes
20:56
FMN & FAD
22:03
Nicotinamide Adenine Dinucleotide (Phosphate)
23:03
Reduction 1/2 Reactions
36:10
Ratio of NAD+ : NADH
36:52
Ratio of NADPH : NADP+
38:02
Specialized Roles of NAD+ & NADPH
38:48
Oxidoreductase Enzyme Overview
40:26
Examples of Oxidoreductase
43:32
The Flavin Nucleotides
46:46
Example Problems For Bioenergetics

42m 12s

Intro
0:00
Example 1: Calculate the ∆G°' For The Following Reaction
1:04
Example 1: Question
1:05
Example 1: Solution
2:20
Example 2: Calculate the Keq For the Following
4:20
Example 2: Question
4:21
Example 2: Solution
5:54
Example 3: Calculate the ∆G°' For The Hydrolysis of ATP At 25°C
8:52
Example 3: Question
8:53
Example 3: Solution
10:30
Example 3: Alternate Procedure
13:48
Example 4: Problems For Bioenergetics
16:46
Example 4: Questions
16:47
Example 4: Part A Solution
21:19
Example 4: Part B Solution
23:26
Example 4: Part C Solution
26:12
Example 5: Problems For Bioenergetics
29:27
Example 5: Questions
29:35
Example 5: Solution - Part 1
32:16
Example 5: Solution - Part 2
34:39
IX. Glycolysis and Gluconeogenesis
Overview of Glycolysis I

43m 32s

Intro
0:00
Overview of Glycolysis
0:48
Three Primary Paths For Glucose
1:04
Preparatory Phase of Glycolysis
4:40
Payoff Phase of Glycolysis
6:40
Glycolysis Reactions Diagram
7:58
Enzymes of Glycolysis
12:41
Glycolysis Reactions
16:02
Step 1
16:03
Step 2
18:03
Step 3
18:52
Step 4
20:08
Step 5
21:42
Step 6
22:44
Step 7
24:22
Step 8
25:11
Step 9
26:00
Step 10
26:51
Overview of Glycolysis Cont.
27:28
The Overall Reaction for Glycolysis
27:29
Recall The High-Energy Phosphorylated Compounds Discusses In The Bioenergetics Unit
33:10
What Happens To The Pyruvate That Is Formed?
37:58
Glycolysis II

1h 1m 47s

Intro
0:00
Glycolysis Step 1: The Phosphorylation of Glucose
0:27
Glycolysis Step 1: Reaction
0:28
Hexokinase
2:28
Glycolysis Step 1: Mechanism-Simple Nucleophilic Substitution
6:34
Glycolysis Step 2: Conversion of Glucose 6-Phosphate → Fructose 6-Phosphate
11:33
Glycolysis Step 2: Reaction
11:34
Glycolysis Step 2: Mechanism, Part 1
14:40
Glycolysis Step 2: Mechanism, Part 2
18:16
Glycolysis Step 2: Mechanism, Part 3
19:56
Glycolysis Step 2: Mechanism, Part 4 (Ring Closing & Dissociation)
21:54
Glycolysis Step 3: Conversion of Fructose 6-Phosphate to Fructose 1,6-Biphosphate
24:16
Glycolysis Step 3: Reaction
24:17
Glycolysis Step 3: Mechanism
26:40
Glycolysis Step 4: Cleavage of Fructose 1,6-Biphosphate
31:10
Glycolysis Step 4: Reaction
31:11
Glycolysis Step 4: Mechanism, Part 1 (Binding & Ring Opening)
35:26
Glycolysis Step 4: Mechanism, Part 2
37:40
Glycolysis Step 4: Mechanism, Part 3
39:30
Glycolysis Step 4: Mechanism, Part 4
44:00
Glycolysis Step 4: Mechanism, Part 5
46:34
Glycolysis Step 4: Mechanism, Part 6
49:00
Glycolysis Step 4: Mechanism, Part 7
50:12
Hydrolysis of The Imine
52:33
Glycolysis Step 5: Conversion of Dihydroxyaceton Phosphate to Glyceraldehyde 3-Phosphate
55:38
Glycolysis Step 5: Reaction
55:39
Breakdown and Numbering of Sugar
57:40
Glycolysis III

59m 17s

Intro
0:00
Glycolysis Step 5: Conversion of Dihydroxyaceton Phosphate to Glyceraldehyde 3-Phosphate
0:44
Glycolysis Step 5: Mechanism, Part 1
0:45
Glycolysis Step 5: Mechanism, Part 2
3:53
Glycolysis Step 6: Oxidation of Glyceraldehyde 3-Phosphate to 1,3-Biphosphoglycerate
5:14
Glycolysis Step 6: Reaction
5:15
Glycolysis Step 6: Mechanism, Part 1
8:52
Glycolysis Step 6: Mechanism, Part 2
12:58
Glycolysis Step 6: Mechanism, Part 3
14:26
Glycolysis Step 6: Mechanism, Part 4
16:23
Glycolysis Step 7: Phosphoryl Transfer From 1,3-Biphosphoglycerate to ADP to Form ATP
19:08
Glycolysis Step 7: Reaction
19:09
Substrate-Level Phosphorylation
23:18
Glycolysis Step 7: Mechanism (Nucleophilic Substitution)
26:57
Glycolysis Step 8: Conversion of 3-Phosphoglycerate to 2-Phosphoglycerate
28:44
Glycolysis Step 8: Reaction
28:45
Glycolysis Step 8: Mechanism, Part 1
30:08
Glycolysis Step 8: Mechanism, Part 2
32:24
Glycolysis Step 8: Mechanism, Part 3
34:02
Catalytic Cycle
35:42
Glycolysis Step 9: Dehydration of 2-Phosphoglycerate to Phosphoenol Pyruvate
37:20
Glycolysis Step 9: Reaction
37:21
Glycolysis Step 9: Mechanism, Part 1
40:12
Glycolysis Step 9: Mechanism, Part 2
42:01
Glycolysis Step 9: Mechanism, Part 3
43:58
Glycolysis Step 10: Transfer of a Phosphoryl Group From Phosphoenol Pyruvate To ADP To Form ATP
45:16
Glycolysis Step 10: Reaction
45:17
Substrate-Level Phosphorylation
48:32
Energy Coupling Reaction
51:24
Glycolysis Balance Sheet
54:15
Glycolysis Balance Sheet
54:16
What Happens to The 6 Carbons of Glucose?
56:22
What Happens to 2 ADP & 2 Pi?
57:04
What Happens to The 4e⁻ ?
57:15
Glycolysis IV

39m 47s

Intro
0:00
Feeder Pathways
0:42
Feeder Pathways Overview
0:43
Starch, Glycogen
2:25
Lactose
4:38
Galactose
4:58
Manose
5:22
Trehalose
5:45
Sucrose
5:56
Fructose
6:07
Fates of Pyruvate: Aerobic & Anaerobic Conditions
7:39
Aerobic Conditions & Pyruvate
7:40
Anaerobic Fates of Pyruvate
11:18
Fates of Pyruvate: Lactate Acid Fermentation
14:10
Lactate Acid Fermentation
14:11
Fates of Pyruvate: Ethanol Fermentation
19:01
Ethanol Fermentation Reaction
19:02
TPP: Thiamine Pyrophosphate (Functions and Structure)
23:10
Ethanol Fermentation Mechanism, Part 1
27:53
Ethanol Fermentation Mechanism, Part 2
29:06
Ethanol Fermentation Mechanism, Part 3
31:15
Ethanol Fermentation Mechanism, Part 4
32:44
Ethanol Fermentation Mechanism, Part 5
34:33
Ethanol Fermentation Mechanism, Part 6
35:48
Gluconeogenesis I

41m 34s

Intro
0:00
Gluconeogenesis, Part 1
1:02
Gluconeogenesis Overview
1:03
3 Glycolytic Reactions That Are Irreversible Under Physiological Conditions
2:29
Gluconeogenesis Reactions Overview
6:17
Reaction: Pyruvate to Oxaloacetate
11:07
Reaction: Oxaloacetate to Phosphoenolpyruvate (PEP)
13:29
First Pathway That Pyruvate Can Take to Become Phosphoenolpyruvate
15:24
Second Pathway That Pyruvate Can Take to Become Phosphoenolpyruvate
21:00
Transportation of Pyruvate From The Cytosol to The Mitochondria
24:15
Transportation Mechanism, Part 1
26:41
Transportation Mechanism, Part 2
30:43
Transportation Mechanism, Part 3
34:04
Transportation Mechanism, Part 4
38:14
Gluconeogenesis II

34m 18s

Intro
0:00
Oxaloacetate → Phosphoenolpyruvate (PEP)
0:35
Mitochondrial Membrane Does Not Have a Transporter for Oxaloactate
0:36
Reaction: Oxaloacetate to Phosphoenolpyruvate (PEP)
3:36
Mechanism: Oxaloacetate to Phosphoenolpyruvate (PEP)
4:48
Overall Reaction: Pyruvate to Phosphoenolpyruvate
7:01
Recall The Two Pathways That Pyruvate Can Take to Become Phosphoenolpyruvate
10:16
NADH in Gluconeogenesis
12:29
Second Pathway: Lactate → Pyruvate
18:22
Cytosolic PEP Carboxykinase, Mitochondrial PEP Carboxykinase, & Isozymes
18:23
2nd Bypass Reaction
23:04
3rd Bypass Reaction
24:01
Overall Process
25:17
Other Feeder Pathways For Gluconeogenesis
26:35
Carbon Intermediates of The Citric Acid Cycle
26:36
Amino Acids & The Gluconeogenic Pathway
29:45
Glycolysis & Gluconeogenesis Are Reciprocally Regulated
32:00
The Pentose Phosphate Pathway

42m 52s

Intro
0:00
The Pentose Phosphate Pathway Overview
0:17
The Major Fate of Glucose-6-Phosphate
0:18
The Pentose Phosphate Pathway (PPP) Overview
1:00
Oxidative Phase of The Pentose Phosphate Pathway
4:33
Oxidative Phase of The Pentose Phosphate Pathway: Reaction Overview
4:34
Ribose-5-Phosphate: Glutathione & Reductive Biosynthesis
9:02
Glucose-6-Phosphate to 6-Phosphogluconate
12:48
6-Phosphogluconate to Ribulose-5-Phosphate
15:39
Ribulose-5-Phosphate to Ribose-5-Phosphate
17:05
Non-Oxidative Phase of The Pentose Phosphate Pathway
19:55
Non-Oxidative Phase of The Pentose Phosphate Pathway: Overview
19:56
General Transketolase Reaction
29:03
Transaldolase Reaction
35:10
Final Transketolase Reaction
39:10
X. The Citric Acid Cycle (Krebs Cycle)
Citric Acid Cycle I

36m 10s

Intro
0:00
Stages of Cellular Respiration
0:23
Stages of Cellular Respiration
0:24
From Pyruvate to Acetyl-CoA
6:56
From Pyruvate to Acetyl-CoA: Pyruvate Dehydrogenase Complex
6:57
Overall Reaction
8:42
Oxidative Decarboxylation
11:54
Pyruvate Dehydrogenase (PDH) & Enzymes
15:30
Pyruvate Dehydrogenase (PDH) Requires 5 Coenzymes
17:15
Molecule of CoEnzyme A
18:52
Thioesters
20:56
Lipoic Acid
22:31
Lipoate Is Attached To a Lysine Residue On E₂
24:42
Pyruvate Dehydrogenase Complex: Reactions
26:36
E1: Reaction 1 & 2
30:38
E2: Reaction 3
31:58
E3: Reaction 4 & 5
32:44
Substrate Channeling
34:17
Citric Acid Cycle II

49m 20s

Intro
0:00
Citric Acid Cycle Reactions Overview
0:26
Citric Acid Cycle Reactions Overview: Part 1
0:27
Citric Acid Cycle Reactions Overview: Part 2
7:03
Things to Note
10:58
Citric Acid Cycle Reactions & Mechanism
13:57
Reaction 1: Formation of Citrate
13:58
Reaction 1: Mechanism
19:01
Reaction 2: Citrate to Cis Aconistate to Isocitrate
28:50
Reaction 3: Isocitrate to α-Ketoglutarate
32:35
Reaction 3: Two Isocitrate Dehydrogenase Enzymes
36:24
Reaction 3: Mechanism
37:33
Reaction 4: Oxidation of α-Ketoglutarate to Succinyl-CoA
41:38
Reaction 4: Notes
46:34
Citric Acid Cycle III

44m 11s

Intro
0:00
Citric Acid Cycle Reactions & Mechanism
0:21
Reaction 5: Succinyl-CoA to Succinate
0:24
Reaction 5: Reaction Sequence
2:35
Reaction 6: Oxidation of Succinate to Fumarate
8:28
Reaction 7: Fumarate to Malate
10:17
Reaction 8: Oxidation of L-Malate to Oxaloacetate
14:15
More On The Citric Acid Cycle
17:17
Energy from Oxidation
17:18
How Can We Transfer This NADH Into the Mitochondria
27:10
Citric Cycle is Amphibolic - Works In Both Anabolic & Catabolic Pathways
32:06
Biosynthetic Processes
34:29
Anaplerotic Reactions Overview
37:26
Anaplerotic: Reaction 1
41:42
XI. Catabolism of Fatty Acids
Fatty Acid Catabolism I

48m 11s

Intro
0:00
Introduction to Fatty Acid Catabolism
0:21
Introduction to Fatty Acid Catabolism
0:22
Vertebrate Cells Obtain Fatty Acids for Catabolism From 3 Sources
2:16
Diet: Part 1
4:00
Diet: Part 2
5:35
Diet: Part 3
6:20
Diet: Part 4
6:47
Diet: Part 5
10:18
Diet: Part 6
10:54
Diet: Part 7
12:04
Diet: Part 8
12:26
Fats Stored in Adipocytes Overview
13:54
Fats Stored in Adipocytes (Fat Cells): Part 1
16:13
Fats Stored in Adipocytes (Fat Cells): Part 2
17:16
Fats Stored in Adipocytes (Fat Cells): Part 3
19:42
Fats Stored in Adipocytes (Fat Cells): Part 4
20:52
Fats Stored in Adipocytes (Fat Cells): Part 5
22:56
Mobilization of TAGs Stored in Fat Cells
24:35
Fatty Acid Oxidation
28:29
Fatty Acid Oxidation
28:48
3 Reactions of the Carnitine Shuttle
30:42
Carnitine Shuttle & The Mitochondrial Matrix
36:25
CAT I
43:58
Carnitine Shuttle is the Rate-Limiting Steps
46:24
Fatty Acid Catabolism II

45m 58s

Intro
0:00
Fatty Acid Catabolism
0:15
Fatty Acid Oxidation Takes Place in 3 Stages
0:16
β-Oxidation
2:05
β-Oxidation Overview
2:06
Reaction 1
4:20
Reaction 2
7:35
Reaction 3
8:52
Reaction 4
10:16
β-Oxidation Reactions Discussion
11:34
Notes On β-Oxidation
15:14
Double Bond After The First Reaction
15:15
Reaction 1 is Catalyzed by 3 Isozymes of Acyl-CoA Dehydrogenase
16:04
Reaction 2 & The Addition of H₂O
18:38
After Reaction 4
19:24
Production of ATP
20:04
β-Oxidation of Unsaturated Fatty Acid
21:25
β-Oxidation of Unsaturated Fatty Acid
22:36
β-Oxidation of Mono-Unsaturates
24:49
β-Oxidation of Mono-Unsaturates: Reaction 1
24:50
β-Oxidation of Mono-Unsaturates: Reaction 2
28:43
β-Oxidation of Mono-Unsaturates: Reaction 3
30:50
β-Oxidation of Mono-Unsaturates: Reaction 4
31:06
β-Oxidation of Polyunsaturates
32:29
β-Oxidation of Polyunsaturates: Part 1
32:30
β-Oxidation of Polyunsaturates: Part 2
37:08
β-Oxidation of Polyunsaturates: Part 3
40:25
Fatty Acid Catabolism III

33m 18s

Intro
0:00
Fatty Acid Catabolism
0:43
Oxidation of Fatty Acids With an Odd Number of Carbons
0:44
β-oxidation in the Mitochondrion & Two Other Pathways
9:08
ω-oxidation
10:37
α-oxidation
17:22
Ketone Bodies
19:08
Two Fates of Acetyl-CoA Formed by β-Oxidation Overview
19:09
Ketone Bodies: Acetone
20:42
Ketone Bodies: Acetoacetate
20:57
Ketone Bodies: D-β-hydroxybutyrate
21:25
Two Fates of Acetyl-CoA Formed by β-Oxidation: Part 1
22:05
Two Fates of Acetyl-CoA Formed by β-Oxidation: Part 2
26:59
Two Fates of Acetyl-CoA Formed by β-Oxidation: Part 3
30:52
XII. Catabolism of Amino Acids and the Urea Cycle
Overview & The Aminotransferase Reaction

40m 59s

Intro
0:00
Overview of The Aminotransferase Reaction
0:25
Overview of The Aminotransferase Reaction
0:26
The Aminotransferase Reaction: Process 1
3:06
The Aminotransferase Reaction: Process 2
6:46
Alanine From Muscle Tissue
10:54
Bigger Picture of the Aminotransferase Reaction
14:52
Looking Closely at Process 1
19:04
Pyridoxal Phosphate (PLP)
24:32
Pyridoxamine Phosphate
25:29
Pyridoxine (B6)
26:38
The Function of PLP
27:12
Mechanism Examples
28:46
Reverse Reaction: Glutamate to α-Ketoglutarate
35:34
Glutamine & Alanine: The Urea Cycle I

39m 18s

Intro
0:00
Glutamine & Alanine: The Urea Cycle I
0:45
Excess Ammonia, Glutamate, and Glutamine
0:46
Glucose-Alanine Cycle
9:54
Introduction to the Urea Cycle
20:56
The Urea Cycle: Production of the Carbamoyl Phosphate
22:59
The Urea Cycle: Reaction & Mechanism Involving the Carbamoyl Phosphate Synthetase
33:36
Glutamine & Alanine: The Urea Cycle II

36m 21s

Intro
0:00
Glutamine & Alanine: The Urea Cycle II
0:14
The Urea Cycle Overview
0:34
Reaction 1: Ornithine → Citrulline
7:30
Reaction 2: Citrulline → Citrullyl-AMP
11:15
Reaction 2': Citrullyl-AMP → Argininosuccinate
15:25
Reaction 3: Argininosuccinate → Arginine
20:42
Reaction 4: Arginine → Orthinine
24:00
Links Between the Citric Acid Cycle & the Urea Cycle
27:47
Aspartate-argininosuccinate Shunt
32:36
Amino Acid Catabolism

47m 58s

Intro
0:00
Amino Acid Catabolism
0:10
Common Amino Acids and 6 Major Products
0:11
Ketogenic Amino Acid
1:52
Glucogenic Amino Acid
2:51
Amino Acid Catabolism Diagram
4:18
Cofactors That Play a Role in Amino Acid Catabolism
7:00
Biotin
8:42
Tetrahydrofolate
10:44
S-Adenosylmethionine (AdoMet)
12:46
Tetrahydrobiopterin
13:53
S-Adenosylmethionine & Tetrahydrobiopterin Molecules
14:41
Catabolism of Phenylalanine
18:30
Reaction 1: Phenylalanine to Tyrosine
18:31
Reaction 2: Tyrosine to p-Hydroxyphenylpyruvate
21:36
Reaction 3: p-Hydroxyphenylpyruvate to Homogentisate
23:50
Reaction 4: Homogentisate to Maleylacetoacetate
25:42
Reaction 5: Maleylacetoacetate to Fumarylacetoacetate
28:20
Reaction 6: Fumarylacetoacetate to Fumarate & Succinyl-CoA
29:51
Reaction 7: Fate of Fumarate & Succinyl-CoA
31:14
Phenylalanine Hydroxylase
33:33
The Phenylalanine Hydroxylase Reaction
33:34
Mixed-Function Oxidases
40:26
When Phenylalanine Hydoxylase is Defective: Phenylketonuria (PKU)
44:13
XIII. Oxidative Phosphorylation and ATP Synthesis
Oxidative Phosphorylation I

41m 11s

Intro
0:00
Oxidative Phosphorylation
0:54
Oxidative Phosphorylation Overview
0:55
Mitochondrial Electron Transport Chain Diagram
7:15
Enzyme Complex I of the Electron Transport Chain
12:27
Enzyme Complex II of the Electron Transport Chain
14:02
Enzyme Complex III of the Electron Transport Chain
14:34
Enzyme Complex IV of the Electron Transport Chain
15:30
Complexes Diagram
16:25
Complex I
18:25
Complex I Overview
18:26
What is Ubiquinone or Coenzyme Q?
20:02
Coenzyme Q Transformation
22:37
Complex I Diagram
24:47
Fe-S Proteins
26:42
Transfer of H⁺
29:42
Complex II
31:06
Succinate Dehydrogenase
31:07
Complex II Diagram & Process
32:54
Other Substrates Pass Their e⁻ to Q: Glycerol 3-Phosphate
37:31
Other Substrates Pass Their e⁻ to Q: Fatty Acyl-CoA
39:02
Oxidative Phosphorylation II

36m 27s

Intro
0:00
Complex III
0:19
Complex III Overview
0:20
Complex III: Step 1
1:56
Complex III: Step 2
6:14
Complex IV
8:42
Complex IV: Cytochrome Oxidase
8:43
Oxidative Phosphorylation, cont'd
17:18
Oxidative Phosphorylation: Summary
17:19
Equation 1
19:13
How Exergonic is the Reaction?
21:03
Potential Energy Represented by Transported H⁺
27:24
Free Energy Change for the Production of an Electrochemical Gradient Via an Ion Pump
28:48
Free Energy Change in Active Mitochondria
32:02
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Lecture Comments (4)

3 answers

Last reply by: Professor Hovasapian
Sat Sep 14, 2013 2:08 AM

Post by Vinit Shanbhag on September 12, 2013

I was wondering how odd chain fatty acids are made, becoz you need a two carbon acetyl coa and a two carbon malonyl coa (after decarboxylation) as precursors.

Fatty Acid Catabolism II

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
  • Fatty Acid Catabolism 0:15
    • Fatty Acid Oxidation Takes Place in 3 Stages
  • β-Oxidation 2:05
    • β-Oxidation Overview
    • Reaction 1
    • Reaction 2
    • Reaction 3
    • Reaction 4
    • β-Oxidation Reactions Discussion
  • Notes On β-Oxidation 15:14
    • Double Bond After The First Reaction
    • Reaction 1 is Catalyzed by 3 Isozymes of Acyl-CoA Dehydrogenase
    • Reaction 2 & The Addition of H₂O
    • After Reaction 4
    • Production of ATP
  • β-Oxidation of Unsaturated Fatty Acid 21:25
    • β-Oxidation of Unsaturated Fatty Acid
  • β-Oxidation of Mono-Unsaturates 24:49
    • β-Oxidation of Mono-Unsaturates: Reaction 1
    • β-Oxidation of Mono-Unsaturates: Reaction 2
    • β-Oxidation of Mono-Unsaturates: Reaction 3
    • β-Oxidation of Mono-Unsaturates: Reaction 4
  • β-Oxidation of Polyunsaturates 32:29
    • β-Oxidation of Polyunsaturates: Part 1
    • β-Oxidation of Polyunsaturates: Part 2
    • β-Oxidation of Polyunsaturates: Part 3

Transcription: Fatty Acid Catabolism II

Hello and welcome back to Educator.com, and welcome back to Biochemistry.0000

Today, we are going to continue our discussion of fatty acid oxidation, fatty acid catabolism, and we are going to actually discuss the oxidation, itself, something called beta-oxidation.0004

Let's jump right on in.0014

OK, fatty acid oxidation, as a whole, it takes place in 3 stages.0018

The first stage is the beta-oxidation.0043

Stage 2 is a citric acid cycle, so the acetyl-CoA that is formed in the beta-oxidation passes through the citric acid cycle just like the acetyl-CoA that was formed from the pyruvate from glycolysis and 3, the oxidative phosphorylation.0050

That is where all of those high-energy electrons from the FADH2 and the NADH are given over to the electron transport chain.0072

Oxygen is reduced to water, and ATP is produced- oxidative phosphorylation.0080

OK, now, we looked at no. 2 in the last unit; that is where we discussed the citric acid cycle.0087

Oxidative phosphorylation, we are going to talk about not the next unit but the unit after that.0094

The next unit, we are going to talk about the breakdown of amino acids, and then, after that, we will go ahead and take a look at the final phase, which all of these things funnel into- the oxidative phosphorylation.0099

Here, we are going to concentrate on beta-oxidation.0111

OK, now, beta-oxidation, this is going to be our primary concern here.0116

Beta oxidation is the successive removal of acetyl-CoA.0126

Well, it is the removal of acetyl groups to carbon groups as acetyl-S-CoA.0150

OK, now, it consists of 4 reactions repeated over and over again.0165

A free fatty acid, that is what we are doing; we have taken this fatty acid and used the carnitine shuttle to bring these fatty acids into the mitochondrial matrix, and at this point, a fatty acid is just some carboxylic acid end with this long chain carbon- 14, 18, 16, 20, 24, however long it is.0190

What we are going to be doing is we are going to be removing 2 carbons at a time as acetyl-CoA - 2, 2, 2, 2, 2 - until the last 2, and that is going to be another acetyl-CoA; and these acetyl-CoAs enter the citric acid cycle.0211

That is what is happening here; these 4 reactions that we are going to diagram in just a moment, they are the 4 reactions that actually split it up over and over and over again until you just run down the chain and you run out of carbons.0223

It consists of 4 reactions repeated over and over again until, well, until you run out of carbons- that is it.0237

That is all that is happening here; OK, let me see if I want to do this on...I do not want to start it on this page.0259

I actually want to do all of the 4 reactions on 1 page, so I am going to go ahead and go to the next page; and I think I am going to keep this in black.0269

These are going to be the 4 reactions of beta-oxidation.0276

I am just going to choose some random fatty acid.0280

It is going to be written as R, C.0284

I am not going to put the Hs actually.0290

Well, maybe I should.0294

I do not know; it is always a tough call.0299

That is OK, I will go ahead and leave the Hs off, R, C, C, C, C, so 1, 2, 3, 4, and we will go ahead and put...this is the S, and this is the CoA.0301

OK, this is our starting fatty acid.0317

It is now an acyl-CoA.0323

Notice, there are no unsaturated, so this particular is for an even number of carbons of fully-saturated fatty acids.0327

Let's see here; let's see what we can do.0340

Our first reaction is going to be the following; our first reaction is going to take us to...let me see.0342

We are going to have FAD to FADH2, and this is catalyzed by - I will do the enzyme in red - acyl-CoA dehydrogenase; and when we do that, what we end up with is the following molecule.0349

This is reaction 1; this is reaction 1, go back here.0380

What we are left with is R, C, C, and here - I actually will put the Hs in to show you that this is actually a trans double bond, not a cis double bond - C, O, S-CoA.0386

OK, this is called a trans-delta2-enoyl- CoA.0410

1, 2, that is what the delta2 means; it means the 2.0423

It means trans, the double bond is trans.0427

OK, this is down; this is up, not cis, and the delta2 means on the no. 2 carbon, carbonyl is the no. 1 carbon, enoyl-CoA.0431

The name does not really matter all that much; it is this, it is the structure that matters.0442

That is what we want you to concentrate on: understanding where the structures are, where the double bonds are, particularly with fatty acid catabolism because double bonds are going to be moving as you will see in just a minute.0446

OK, now, the next reaction: 1, 2, 3.0456

I hope I have enough room for this; well, you know what, if I do not, it is not a problem.0464

H2O comes in, and this one...well, let me go ahead and draw the molecule, itself.0470

We have R; we have C.0478

We have COH, H.0482

we have CH, and H, 1, 2, 3 here and S-CoA.0487

Let's make sure 1, 2, 3, 4, 1, 2, 3, 4 good, that is nice.0498

Alright, this is enoyl-CoA hydrotase.0506

OK, and I will be going over this in just a minute; I am just drawing them out right now.0518

Let's go ahead and go...let me see.0522

I think I will go down this way.0529

Well, let me see; actually, you know what, I think i am going to go down this way.0535

I will go down here; this one, NAD+, NADH + H+.0541

By the way, this is reaction 2; this is going to be reaction 3, and the molecule that we are going to form is going to be - no, let's go ahead and go back to black - R1, 2, 3, 4.0556

This is going to be S; this is going to be CoA, alpha-beta.0577

We are going to be...that is ketone there; that is exactly right.0581

OK, and the enzyme that catalyzes this is called...oh, boy, this is beta-hydroxy acyl-CoA dehydrogenase.0585

And, of course, the last reaction is going to be...go ahead and do it like that, and what we have coming in is CoA, SH.0610

This is going to be reaction no. 4; it is going to be catalyzed by acyl-CoA, acetyl transferase, otherwise known as thiolase, and the molecule that you are going to end up with or the 2 molecules you are going to end up with is R, C, C, double bond, S-CoA + the CH3, C, this S-CoA.0634

Here, you are going to have your acetyl-CoA, your first acetyl-CoA group that has been taken off, and here you have the remaining molecule.0683

Let's go ahead and take a look at what is going on here; these are the reactions of beta-oxidation.0694

We start off with this acyl-CoA fully saturated even number of carbons.0699

The first reaction is going to be the conversion of this thing into an alpha-beta unsaturated acyl-CoA.0705

OK, what we have done is...this is a dehydrogenase.0718

We are pulling away some hydrogens; we are going to pull away some hydrogens, and we are going to create this trans double bond.0722

That is what is important; this is trans, not cis.0727

OK, we are actually creating a point of unsaturation.0730

This is alpha; this is beta, so this is an alpha-beta or 2,3 if you want to think about it.0735

This is the no. 1 carbon; this is the no. 2 carbon.0741

Let me go ahead and mark these; this is the no.1.0745

This is the no. 2; this is the no. 3.0748

We are creating a double bond between the 2,3 carbon, and this is catalyzed by acyl-CoA dehydrogenase; and FAD, it is a dehydrogenase.0750

It is an oxidation; FAD is converted to FADH2, so, one of those is produced.0759

Now, from here, we have this thing called a trans-delta2-enoyl-CoA, and again, the name is unimportant.0767

What matters is the molecular structure.0772

You have a carbonyl, and at the 2,3 position, at the alpha-beta position, you have a point of unsaturation.0776

The next reaction catalyzed by enoyl-CoA hydrotase actually adds water across the double bond.0782

What you are going to be doing is adding H, adding OH.0790

Now, what you have is an alpha-beta hydroxy; it is a beta-hydroxy acyl-CoA, right?0794

Here is the carbonyl, and this is the alpha; this is the beta-carbon.0800

You have a hydroxy group attached to that; OK, at this point, the enzyme beta-hydroxy acyl-CoA dehydrogenase, now it dehydrogenase, it oxidizes that.0804

So, it is going to take away this hydrogen and this hydrogen to create a beta-keto.0814

Now, again, NAD+ is the electron acceptor at this point.0820

It is the oxidizer; it is going to turn into NADH, so we are forming one of these in the third step, and notice, now, this alcohol is now a ketone.0827

Now, you have 2 carbonyls on here, and at this point, here is where we are going to break it up.0837

This acyl-CoA acetyltransferase, this thiolase enzyme, another CoA comes in, and what ends up happening is you break this bond, right here.0842

OK, when you break this bond, you are going to release this molecule as your acetyl-CoA, and now, your original molecule, this CoA, it is now, turned into another acyl-CoA; but now, it is 2 carbons shorter.0854

That is what you are doing; you are just 2 carbons, 2 carbons, 2 carbons.0871

These 4 reactions happen over and over and over again, so you go from 12, 10, 8, 6, 4, 2- you are done.0875

That is what is going on; these are the reactions that are important.0883

Unsaturated, you introduce a point of... I am sorry; saturated, you introduce a point of unsaturation, alpha-beta.0887

It is in the trans configuration; you go ahead and you hydrate that double bond.0895

You convert that hydroxy to a keto, and then, you split that bond, right there; and then, you create 2 molecules.0899

You release acetyl-CoA, that is what is happening.0906

OK, let's go ahead and say a couple of words about this.0910

Let's say...take some notes here.0916

Now, first note: the double bond.0922

After the first reaction, is trans.0935

OK, it is a trans.0940

Most natural unsaturates are cis.0945

Natural unsaturation points are cis.0952

OK, reaction no. 1 is catalyzed by 3 isozymes - and we know what isozymes are - of acyl-CoA dehydrogenase.0965

OK, the one that is used depends on the length of the carbon chain in the fatty acid.0995

The one used depends on the length of the carbon chain.1002

If we have 12-18 carbon, it is called VLCAD, very long-chain acyl dehydrogenase- that is it.1019

B: if we have 4-14 carbon, we call it MCAD - exactly what you think - medium-chain acyl dehydrogenase, and if we have let's say 4-8 carbons, well, SCAD.1039

And again, these names, they are not important.1061

All you need to know is that this actually happens; it is the 3 isozymes, short-chain acyl dehydrogenase.1064

Biochemistry is just overfull of abbreviations.1070

Be able to separate what is important, what is not; it is the chemistry that is important, not the nomenclature.1076

You can always look up the nomenclature; there are glossaries of these things available, so do not worry about it.1081

OK, now, what is interesting about this is all 3 are flavoproteins - remember, we talked about these - having FAD as a prosthetic group, and you notice the first reaction, it is FAD that is actually used as the oxidizer.1086

OK, now, in reaction no. 2, H2O adds across the alpha-beta double bond - I will write it this way, how is this - to form a beta-hydroxy acyl-CoA.1118

OK, now, after reaction no. 4, you are left with acetyl-CoA and a fatty acyl-CoA that is 2 carbons shorter.1165

That is the idea.1200

OK, now, FADH2 goes and gives us electrons to the electron transport chain.1205

FADH2 produces 1.5 ATP per 2 electrons.1217

Well, the NADH that is formed also gives its electrons to the electron transport chain.1223

It produces 2.5 ATP.1230

Per cycle, those 4 reactions of beta-oxidation 2.5, 1.5, 4 ATP molecules are produced.1234

For every acetyl-CoA that is cut off, 2 carbons, you are producing 4 ATP.1243

If you end up with an 8-carbon fatty acid - well, that consists of 2, 4, 6, 8 - you end up producing 16 ATP.1248

You can see why oxidizing fatty acids is very, very highly energetic.1256

It produces a hell of a lot of adenosine triphosphate, so 4 ATP per 4 reaction cycle.1265

Every time you go through the cycle of 4 reactions, you create 4 ATP from those high-energy that are donated to the electron transport chain.1275

OK, now, let's see; let's go back to black here.1285

These 4 reactions - let's see - are the basic 4 reactions for saturated fatty acids having an even number of carbons.1289

OK, now, many - I should say most - of the fatty acids in triacylglycerols - in TAGs - are unsaturated.1330

They have 1 or more double bonds.1348

OK, beta-oxidation of the unsaturated fatty acids, we have bonds of unsaturation are cis.1357

Points of unsaturation in the fatty acids that make up most of the triacylglycerols, they are naturally cis.1396

They do not come and transform, they come as points of unsaturation that are cis stereochemistry at the double bond, but the enzyme enoyl-CoA hydrotase requires the fatty acid to be trans.1405

That is what that first reaction does, is when it creates that double bond, that dehydrogenase, it creates a trans double bond, not a cis double bond.1438

The reaction no. 2 cannot take a naturally occurring unsaturated fatty acid, and just go ahead and use it because it does not accept cis double bonds.1450

It needs trans stereochemistry; we need an enzyme that actually makes some changes before beta-oxidation can continue, and that is what we are going to do.1459

Bonds of unsaturation are cis, but the enoyl-CoA hydrotase, which is reaction no. 2, requires the fatty acid to be trans.1468

OK, now, let's go ahead and run through this scheme for the beta-oxidation of monounsaturates.1478

We are going to do this separately; we are going to do 1 point of unsaturation and then, multiple points of unsaturation.1484

The first one we want to look at is the beta-oxidation of monounsaturates.1490

OK, let's go ahead and start with just some random example here, so I will go ahead and draw this out.1507

I have got C, C, C.1513

There is my point of unsaturation; that is C, C.1518

I have got another couple, and I have got another couple just to...OK, and I have S-CoA.1523

Again, let me just make sure that I have the right number of carbons here: 2, 2, 2, 2, 2.1530

I have got 2 here, 2 here, 2 here; everything looks good.1535

OK, the first thing we are going to do is we are going to, of course...well, let me just go ahead and draw this out first.1540

It is 1 cycle; that is 2 cycle.1548

I have got 2 acetyl-CoAs come out; 2 acetyl-CoA comes out from 2 cycles, and what I am left with is the following.1552

I am left with C, C, C, double bond C.1565

This is C, and I have got 1.1570

I have got 2; I have got this one right here, so what I am left with is the following: S-CoA.1574

OK, the first thing that happens here is...let me see.1584

This is our unsaturated acyl-CoA; here is our point of unsaturation.1590

Up to here, it is actually normal; the 2 cycles of normal beta-oxidation, 4 reactions then another 4 reactions, we end up doing this.1596

The first cycle goes ahead and releases that one, so those 2 carbons are gone as acetyl-CoA; and then, the second cycle takes these 2.1605

So, now, we have released 2 molecules of acetyl-CoA and 2 cycles of beta-oxidation.1614

What we are left with is the following; now, we have a double bond on this carbon here, right?1620

That is this carbon; we have this acyl-CoA.1625

OK, it is at this point that some things are going to be happening.1630

Now, let me go ahead and do this in...yes, that is fine; I will go ahead and do this in blue again.1635

Here, what we have is the following; I will go ahead and draw this, and the enzyme that catalyzes this, this new enzyme that needs to make a change is called delta(3)-delta(2)-enoyl-CoA isomerase.1643

Basically, all we are going to do is we are going to shift the double bond.1667

We are going to move the double bond from here, the 3,4 position, and we are going to change it to a 2,3 double bond.1671

OK, what happens here is the following.1679

What this reaction does is it changes the double bond from 3,4 double bond to 2,3 double bond.1685

This is a 3rd carbon, 4th carbon, 2nd carbon, 3rd carbon.1700

This is 1, 2, 3, 4; we are just going to move the double bond over.1704

This delta(3)-delta(2)-enoyl-CoA isomerase, this enzyme affects this change, and what we end up with is the following.1709

Let me go back to blue here.1718

Let me go to the next page; oops, I am here.1722

Let me go to the next page, and what I end up with is the following molecule.1727

C, C, C, now, that is a single bond; I am going to leave them where they are, C, C, O, S-CoA.1732

I left the structure alone; I have moved the double bond from here to here- there we go.1743

Now, from this point, beta-oxidation is normal.1750

I have the acetyl-CoA, and then, I have an alpha-beta unsaturation.1754

This is where we got to after reaction 1, so from this point - I will write it up here, no, that is fine, I will write down here, I should say normal beta-oxidation - normal beta-oxidation continues starting with reaction no. 2.1759

OK, alright, now, I am going to take this and bring it over here.1800

Let me go ahead and bring this down here.1807

I will go ahead and put...reaction no. 2 of the normal beta-oxidation does the following.1812

It actually converts it to this.1819

I have got C, C, C, C, C, C.1822

I have that, and I have the S-CoA - right - and I have got myself a hydroxy here now.1832

I have an H here now; I have got an H, and I have got an H, and then, reaction no. 3 carries me to the keto.1847

I have got C, C, C, C.1857

This is, now, keto; this is C, C, O, S-CoA, and then, of course, I have got reaction no. 4, which gives me...it is going to break the bond right here.1860

I produce C, C, C, C.1876

I produce 1 acyl-CoA, and, of course, I have my resulting acetyl-CoA plus the C, C, S-CoA.1882

I will go ahead and do that; from here on in, it just goes on with normal beta-oxidation.1894

It breaks this up to release this acetyl-CoA, and then, of course, you are left with that acetyl-CoA.1900

That is all that is happening here; as far as if you have a fatty acid that has 1 point of unsaturation, it will run beta-oxidation up until a certain point, but then, what it will do, this isomerase, it will actually change the double bond from a 3,4 position to a 2,3 position, in other words, from a beta-gamma to an alpha-beta double bond.1906

That is all that is going to happen for 1 point of unsaturation.1930

OK, and again, 2 more cycles produces your acetyl-CoA.1935

Now, let's go ahead and take a look at the beta-oxidation of a polyunsaturate, something that has 2 or more points of unsaturation.1940

OK, beta-oxidation of polyunsaturates, and the particular example that I am going to use for my fatty acid, it is going to be just something that has 2 points of unsaturation.1949

Let's go ahead and draw the molecule and run through the reactions.1973

We have got - let me see - 1, 2; yes, that is fine.1979

OK, we have got C, C, C, C, double bond C, C, C, double bond C, another carbon, another carbon, another carbon, another carbon, another carbon, another carbon, and I think we will go ahead and stop there.1986

We have S-CoA; we have something like that, 2 points of unsaturation.2002

Let's see what happens here; 2 cycles - OK - releases 2 acetyl-CoAs.2008

We have 2 cycles of normal, right?2020

We break this bond here; we release that acetyl-CoA.2024

We break this bond here; we release those 2 carbons as acetyl-CoA, and what we are left with is the following.2028

We have got C, C, C, C, double bond C, down to number C, up there, up there, up there.2035

This is C; this is C.2046

Now, what we are left with is that.2049

OK, at this point, this enoyl isomerase does the same thing.2054

Notice, we have...this is the no. 1 carbon; this is the no. 2.2060

This is the 3, and this is the 4; what we are going to do is we are going to remove this double bond from the 3,4 position to the 2,3 position.2065

In this particular case, what we are going to have is the reaction that is catalyzed by the delta-3 to the delta(2)-enoyl-CoA isomerase just like the reaction that we just did.2071

We are just dealing essentially with 1 saturation point at a time.2092

We have come to this 1 saturation point; now, we are going to move it here, and continue on with beta-oxidation until we get to the other unsaturation point.2096

OK, this gives us the following.2105

I have got C, C, C, C, double bond C, C.2112

Now, I have a single bond here, and I have a double bond, which is trans- OK, very, very important.2119

That double bond that is formed that is alpha-beta, that is trans.2125

That is the whole idea; this goes there, and this is S-CoA.2131

OK, now, at this point, what happens is the following.2142

We have...well, OK, at this point the normal reaction no. 2, reaction no. 3 and reaction no. 4 of your normal beta-oxidation take place in order to remove this acetyl-CoA.2152

OK, let me go ahead and write reactions 2, 3 and 4 of normal beta-oxidation take place, and what you end up with is the following.2173

You end up with the following molecules: C, C, C, C, double bond C.2194

This goes there; this goes there.2201

That goes there, and now, what you have broken is this bond to release this S-acetyl-CoA; and what you are now left with is this molecule right here.2205

OK, now, from this point, here is what happens.2225

Reaction no. 1 from normal beta-oxidation: when you do reaction no. 1, you are going to introduce that reaction no. 1 actually introduces a trans double bond into a point of saturation.2232

We are going to put a double bond between the 2 and the 3 carbon.2244

What you end up with is the following molecule.2249

You end up with blue; oops, where is my...OK, there is my...I am left with C, C, C.2255

There is 1 of my double bonds; there is that one I have moved.2266

I have introduced a double bond here- S-CoA.2273

OK, now, at this point, notice what I have got.2281

I have 2 double bonds now; this is 1, 2, 3, 4, 5 carbon.2285

I have a double bond on the 2,3; I have a double bond on the 4,5.2293

The next enzyme, what it does is it takes...it is a reductase.2298

What it is going to do is the opposite of the dehydrogenase; it is going to add hydrogens.2302

It is going to reduce this molecule, but it is going to take these 2 double bonds; and it is going to switch it to a single bond between the 3 and the 4.2307

Let's see what happens; let's go ahead and do this.2316

OK, this time, NADPH + H+ goes to NADP, and this is called 2,4-dienoyl-CoA reductase.2323

OK, and what it is going to do - let me actually draw up the molecule first - it is going to be C, C, C, C, double bond.2350

No, we just said that it is going to actually change that double bond; that is going to be single.2365

That is going to be double; that is going to be single, and that is going to be single- S-CoA.2370

OK, here, a 2,3 double bond and the 4,5 double bond are replaced by a 3,4 double bond- OK, very, very important.2380

The 2,3, the 4,5, that is why they call it 2,4 dien; this is a 2,4 dien.2405

These 2 double bonds are taken away; it is reduced, and it is replaced by a double bond between the no.3 and the no.4 carbon.2411

Here you go; you have 1, 2, 3, 4, 5.2418

That is what happens there; OK, now, at this point, what you have is another application of the enzyme enoyl-CoA isomerase, and what happens here is that the 3,4 double bond is converted to a 2,3 double bond because again, we need that alpha-beta double bond in order to continue with the normal reactions of beta-oxidation.2424

That is all that is happening here; we are just moving double bonds around.2459

3,4 double bond is converted to a 2,3 double bond, and what you end up with is the following molecule.2463

You get C, C, C.2475

This is C; this is C.2480

Now, this is single; now, this is double, and this is C.2483

This is O, S-CoA.2488

Now, we have 1, 2, 3.2492

We have a 2,3 double bond that we need; this is the one that can now undergo the hydrotase reaction, which attaches an alcohol group, and then, that alcohol group becomes a ketone group, and then, we can cut off those 2 carbons.2497

This is no. 2 carbon or if you like, alpha-beta- an alpha-beta double bond.2511

OK, now, at this point, we can go ahead and run our reactions 2, 3 and 4.2521

Under normal conditions, we are going to release an acetyl-CoA, which is this one, a C, C.2531

We are going to break the double bond here.2541

We are going to release this acetyl-CoA, and then, of course, now, we just have a couple of more cycles.2544

At this point, what we are left with is 1, 2, 3, 4, 5, 6 carbons.2550

OK, at this point, what you are left with is 1, 2, 3, 4, 1, 2, 3, 4, 5.2555

I will put the 6th carbon up here because I need to write the S-CoA.2564

Now, it is normal beta-oxidation at this point- 3 cycles of that 4-reaction sequence.2570

This is cut off and released as acetyl-CoA; this is cut off and released as acetyl-CoA, and, of course, the last 2 are released as acetyl-CoA.2575

Again, it looks like there is a lot that is going on here but there is actually not.2585

You have 4 basic reactions of the beta-oxidation.2590

When you introduce a point of unsaturation, there is only that 1 extra enzyme so that isomerase that needs to change the double bond from the 3,4 position to the 2,3 position, and then, beta-oxidation can just continue as normal.2596

But when you have multiple points of unsaturation, you actually need to take care of that first part first.2612

It goes through normal beta-oxidation, and then, you just start moving double bonds around.2620

That is all that is going on here; you are just moving double bonds around in order to get to a point where you have some acyl-CoA that looks like this.2624

You have the acyl-CoA part here, but you want your double bond to be in the alpha-beta; and you want it to be a trans.2634

That is what you want; you want to get a 2,3 double bond.2643

All of these enzymes, they are all geared to do that, so that reaction 2, reaction 3, reaction 4 of the normal beta-oxidation can take place.2647

Go through this very, very carefully.2658

There are several diagrams of this in your book, I promise you; or if you want, you can pull them up on the web.2663

It is not a problem; some of them have a lot of information on there.2670

It is a little hard to read; some of them have very, very little information, but definitely spend time with those diagrams and spend time...pick a couple of fatty acids.2672

They do not have to be very, very long chain, but go through the process yourself physically drawing it out, drawing out each individual step; because again, the only way to really understand what is going on is not to do it passively but to do it actively.2682

Draw out the carbons; draw out the double bonds.2697

Write in the enzyme names; that is the only way that any of this is going to make sense, but make sure you are very, very careful and very detailed about what is going on because the double bonds are moving, and it is very, very subtle.2701

It is very easy to get lost in all of these carbons and oxygens, I mean, very, very easy to get lost, to miss a carbon.2712

By missing a carbon, all of sudden, you have gone from an even number of carbons to an odd number of carbons; it is very difficult to keep track of.2719

When doing this I would recommend not using line structures.2726

I, myself, to this day, I do not use line structures; I like to see every single carbon that I am working with.2731

So, by all means, until you get really, really, really used to this stuff, do not use line structures.2737

They look good, but it is the understanding that you want; we want you to be able to recreate this, to replicate this.2743

OK, thank you for joining us here at Educator.com; we will see you next time for the final words and the continuation of fatty acid catabolism, bye-bye.2750

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