How many ATP are produced per FADH2 during oxidative phosphorylation?

During oxidative phosphorylation, the electron transport chain utilizes electrons from both NADH and FADH2 to produce ATP. FADH2 contributes its electrons to the electron transport chain at a later stage than NADH, specifically at Complex II (succinate dehydrogenase).

When electrons from FADH2 are shuttled through the electron transport chain, they result in the pumping of protons (H+) across the inner mitochondrial membrane, ultimately leading to the generation of a proton gradient. This gradient powers ATP synthase to produce ATP as protons flow back into the mitochondrial matrix.

Quantitatively, it has been established that each pair of electrons from one molecule of FADH2 results in the production of approximately 1.5 ATP via oxidative phosphorylation. However, in the context of the commonly accepted conversion in biochemistry, it is often rounded to 2 ATP.

Thus, the correct choice indicates that for every molecule of FADH2, approximately 2 ATP molecules are generated during the process of oxidative phosphorylation.