Question Detail
Question
How many molecules of ATP would be synthesised if one pyruvate molecule passes through the oxidative steps?
Correct Answer
Option A is the correct answer.
Detailed Explanation
The complete oxidation of one pyruvate molecule via the pyruvate dehydrogenase complex (producing 1 NADH) and the Krebs cycle (producing 3 NADH, 1 FADH2, and 1 ATP/GTP) yields a total of approximately 12 ATP molecules. This calculation uses the approximate yield of 2.5 ATP per NADH and 1.5 ATP per FADH2: (4 NADH × 2.5 = 10) + (1 FADH2 × 1.5 = 1.5) + 1 ATP = 12.5, typically rounded down to 12 ATP.
Hint
Trace the fate of one pyruvate through the link reaction and Krebs cycle, summing the ATP equivalents produced.