Question

H3H 4.72 Calculate the net number of ATPs produced when carbon fatty acid is activated, undergoes B oxidation, snd the products pass through the citric one acid cycle ani she electron transport chain ketone bodies.

Answer 1

Ans.

Step 1: Activation of Fatty acids: One round per fatty acid (FA) molecule FA (Cn) + HS-CoA + ATP + H2O → Acyl-CoA (Cn) + AMP + 2Pi + 2H Step 2: Beta oxidation: n Number of C-atoms in even-numbered FA n-2 10-2 No. of β-oxidation cycles- 2 Acyl-CoA (C20)4 CoA 4 NAD4 FAD4 H2O 5 Acetyl-CoA4 NADH4 FADH24 H Step 3: Acetyl-CoA enters TCA Cycle 5 Acetyl-CoA15 NAD+5 FAD5 ATP15 NADH 5 FADH2 10 CO2 # Summar izing ATP yield: Total NADH4 (Step 2) 15 (Step 3)19 Total FADH,-4 (Step 2) + 5 (Step 3) = 9 ATP Yield: 2.5 ATP NADH 1.5 ATP -L FADH2 From NADH x 19 NADH 47.5 ATP x 9 FADH213.5 ATP From FADH2 = Substrate level phosphorylation (TCA) 5 ATP -2 ATP 64 ATP ATP consumed in FA activation- Net Gain =

Note: The net ATP gain would increase if you account (3 ATP/ NADH) and (2 ATP/ FADH₂) instead of 2.5 and 1.5 ATP, respectively. So, refer to your book for the actual yield of ATP per NADH and FADH₂ and use the result accordingly.