Lipid Metabolism

Question 1

Reactions of β-oxidation

Answer 1

1. Oxidation (produces FADH2)
2. Hydration (addition of H2O)
3. 2nd oxidation (produces NADH)
4. Thiolytic cleavage (releases molecule of acetyl CoA)

Question 2

Fatty acid activation

Answer 2

• Converted to fatty acid CoA derivative by fatty acid CoA synthetase (thiokinase) in cytosol
• Requires 2 ATP

Question 3

β-oxidation result

Answer 3

Each cycle produces: 1 acetyl group + 1 NADH + 1FADH2

Question 4

Oxidation of FA with even number of carbons

Answer 4

Each cycle repeated (n/2) - 1 times

Final thiolytic cleavage produces 2 acetyl groups

Question 5

Oxidation of FA with odd number of carbons

Answer 5

• Proceeds by same mechanism

* Final 3 carbons (propionyl CoA) metabolised by 2-step pathway