Question

Approximately how many total ATP equivalents are generated by the complete oxidation of one molecule of acetyl CoA via the citric acid cycle?a) 1.5b) 2.5

c) 10
d) 30

Answer 1

C. 10 ATP molecules

Step-by-step explanation:

In the citric acid cycle is a series of eight reactions steps in which a two-carbon molecule, acetyl-CoA, enters the cycle through citrate and two atoms of carbon are removed as two molecules of carbon dioxide.

The energy generated by the complete oxidation of one molecule of acetyl CoA via the citric acid cycle is conserved in the production of three NADH molecules, one FADH₂ and one ATP molecule. Each NADH molecule transfers two electrons to oxygen in the electron transport chain, forming 2.5 ATP molecules each in the process. Similarly, an FADH2 molecules transfers two electrons to oxygen in the electron transport chain yielding 1.5 ATP molecules.

Total ATP molecules produced:

3 NADH + 1 FADH2 + 1 ATP = (2.5 × 3) + (1.5 × 1) + 1 ATP = 10 ATP molecules

Therefore, 10 ATP molecules are generated by the complete oxidation of one molecule of acetyl CoA via the citric acid cycle.