Question

NADH and FADH2 carry high-energy electrons that are used to power the production of ATP in the mitochondria. These cofactors are generated during glycolysis, the citric acid cycle, and the fatty acid oxidation cycle. Which molecule below can produce the most ATP? Explain your answer.

(a) NADH from glycolysis
(b) FADH2 from the fatty acid cycle
(c) NADH from the citric acid cycle
(d) FADH2 from the citric acid cycle

Answer 1

NADH from the citric acid cycle can produce the most ATP.

Step-by-step explanation:

The molecule that can produce the most ATP is (c) NADH from the citric acid cycle.

In the citric acid cycle, each NADH molecule can produce about 3 ATP when it undergoes oxidative phosphorylation in the electron transport chain. On the other hand, each FADH2 molecule can produce about 2 ATP. Therefore, NADH can produce more ATP compared to FADH2.

For every glucose molecule that enters aerobic respiration, a net total of 36 ATPs are produced. This includes the ATP generated from NADH in the citric acid cycle and glycolysis.