Question

Explain why FADH2 produces fewer ATP molecules than NADH when it passes its electrons down the Electron transport chain.

explain in 3 sentences

Answer 1

FADH2 produces fewer ATP molecules than NADH because it donates its electrons to the electron transport chain at a lower energy level, specifically at Complex II, whereas NADH donates at Complex I. This positioning means that fewer protons are pumped across the mitochondrial membrane when electrons from FADH2 are transferred, resulting in less proton motive force. Consequently, fewer ATP molecules are synthesized via ATP synthase when FADH2 is oxidized, typically yielding about 1.5 ATP compared to the 2.5 ATP produced from NADH.