Question

Why does a single molecule of NADH result in the production of more ATP

molecules than a single molecule of FADH2 via oxidative phosphorylation?

A. NADH donates more electrons to the chain.
B. FADH2 feeds its electrons into the electron transport chain further along the
chain.
C. FADH2 is less likely than NADH to participate in the electron transport chain.

Answer 1

A single molecule of NADH produces more ATP than FADH2 in oxidative phosphorylation because NADH donates electrons at an earlier stage in the electron transport chain, allowing for more proton pumping and a larger proton gradient.

Step-by-step explanation:

The reason a single molecule of NADH results in the production of more ATP molecules than a single molecule of FADH2 during oxidative phosphorylation is because FADH2 feeds its electrons into the electron transport chain further along the chain, specifically at Complex II, compared to NADH which donates electrons at Complex I. Therefore, electrons from FADH2 bypass the first proton pump, resulting in the generation of fewer ATP molecules.

Through the process of oxidative phosphorylation, approximately three ATP molecules are produced for every molecule of NADH oxidized, whereas about two ATP molecules are produced for every molecule of FADH2 oxidized. This difference is because NADH donates its electrons earlier in the electron transport chain, allowing for more proton pumping and the establishment of a larger proton gradient to drive the synthesis of ATP via ATP synthase.