Beta Oxidation Part I

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Beta Oxidation Part I
The break down of a fatty acid to
acetyl-CoA unitsthe glycolysis of fatty acids
STRICTLY AEROBIC
Occurs in the mitochondria
Acetyl-CoA is fed directly into the Krebs cycle
Overproduction causes KETOSIS
Exemplifies Aerobic Metabolism at its most
powerful phase
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Schedule of Topics
Fatty Acid Oxidation

• Digestion, absorption and transport
• General mechanism of fatty acid oxidation
• Oxidation of unsaturated fatty acids
• Odd chain fatty acidsrole of vitamin B12
• Ketone bodies and ketosis

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CH3CH2CH2COOH
CH3CH2CH2CO-AMP
Fatty acyl CoA Ligase
CH3CH2CH2COSCoA
Fatty acyl CoA
Prepares a Fatty Acid for transport and metabolism
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Transport into Mitochondria depends on Carnitine
FACoA
FACarnitine
Translocase
FACarnitine
Carnitine
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Beta Oxidation
8 carbon Fatty Acid Acyl-CoA
4 two carbon Acetyl-CoAs
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Knoops Experiment
Phenylacetate
Benzoate
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MECHANISM
Round
Dehydrogenase
FAD

TRANS
Hydratase
H2O
L-
Dehydrogenase
NAD
Acyl Transferase
HS-CoA
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Remember
Trans L Vania
When you think of beta oxidation
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THE ENERGY STORY PART I
Glucose
C6H12O6 6O2 ? 6CO2 6H2O ?Ho -2,813
kJ/mol - 672 Cal/mol
3.74 Cal/gram
Stearic Acid
C18H36O2 26O2 ? 18CO2 18 H2O ?Ho
-11,441 kJ/mol - 2,737 Cal/mol
9.64 Cal/gram
On a per mole basis a typical fatty acid is 4
times more energy rich that a typical hexose
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Energy Story Part II
1.0 g glucose 3.7 kcal (15.5 kJ)
1.0 g stearic acid 9.7 kcal (40.5 kJ)
ENERGY CONSERVATION
Stearic Acid (C18 satd)
Textbook
9 Acetyl CoA 108 ATP (90)
8 FADH2 16 ATP (24)
8 NADH 24 ATP (20)
148 ATP (134)
- 1 ATP -1
147 ATP (133)
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Palmitoyl-CoA (Textbook)
Palmitoyl-CoA 7CoA 7FAD 7NAD 7H2O
8 Acetyl-CoA 80 ATP
7 FADH2 10.5 ATP
7 NADH 7H 17.5 ATP
108 ATP
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R-1
R-2
R-3
CH3CH2 CH2CH2 CH2CH2 CH2COSCoA
FAD
FAD
FAD
NAD
NAD
NAD
HS-CoA
HS-CoA
HS-CoA
C-8
Octoyl-CoA 3HSCoA 3FAD 3NAD 7H2O
4 Acetyl-CoA 40 ATP
3 FADH2 4.5 ATP
3 NADH 3 H 7.5 ATP
52 ATP
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?1
?2
?3
CH3CH2 CH2CH2 CH2CH2 CH2COSCoA
FAD NAD HSCoA
CH3CH2 CH2CH2 CH2COSCoA
FAD NAD HSCoA
CH3CH2 CH2COSCoA
FAD NAD HSCoA
CH3COSCoA
CH3COSCoA
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Hexanoic acid
(C6H12O2)
Glucose (C6H12O6)
Hexanoic acid
Glucose
Hexanoyl-CoA
-1 ATP
2 pyruvates
2 ATP
2 NADH H
5 ATP
Hexanoyl-CoA
2 pyruvates
3 Acetyl-CoA
30 ATP
2 Acetyl-CoA
20 ATP
3 ATP
2 FADH2
2 NADH H
5 ATP
2 NADH H
5 ATP
32 ATP
37 ATP
Mwt 116
Mwt 180
ATP per Gram 0.32
ATP per Gram 0.17