Question

TCA cycles, starting from two pyruvates to 6 CO2, generate 2 ATP, 8 NADH, and 2 FADH. How many ATPs are generated at each of the following processes? (use the data given here and the conversion factors 1 NADH=3 ATP, 1 FADH=2 ATP)

1) Substrate-level phosphorylation

2) Oxidative phosphorylation (aerobic respiration)

3) All ATP produced (both substrate level and oxidative phosphorylation)

Answer Choices
A. 28
B. 38
C. 30
D. 2
E. 34
F. none of above

Answer 1

1. ATP produced at substrate level phosphorylation of Kreb's cycle are : 2 ATP

And ATP produced at substrate level phosphorylation of Glycolysis are : 4 ATP

2.After Glycolysis,  6 ATP are generated through oxidative phosphorylation of 2NADH₂. After link reaction , there is also 6 ATP produced via Oxidative phosphorylation of 2NADH₂ . While after Kreb's cycle 22 ATP are generated through Oxidative phosphorylation of 6 NADH₂ and 2FADH₂ . Therefore, a total of 34 ATP is produced through oxidative phosphorylation.

3. Substrate level phosphorylation in glycolysis produces 4 ATP,

substrate level phosphorylation in kreb's cycle produces 2 ATP,

And overall ATP production through Oxidative phosphorylation are 34 ATP,

Therefore total ATP produced are 40 ATP.

Although , 2 ATP consumed during glycolysis.