What is the total amount of FADH2 produced by aerobic respiration?

In the context of aerobic respiration occurring in eukaryotic cells, the process consists of glycolysis, the citric acid cycle (Krebs cycle), and the electron transport chain. The citric acid cycle, which takes place in the mitochondrial matrix, is a crucial stage where significant electron carriers are produced, including FADH2.

During one turn of the citric acid cycle, 1 FADH2 is produced per acetyl-CoA. Since each molecule of glucose generates two molecules of acetyl-CoA (one through the transition step from pyruvate), the total production of FADH2 from a single glucose molecule is therefore 2 FADH2.

This accounts for the full yield of electron carriers during aerobic respiration. Additionally, during glycolysis, two additional reduced electron carriers, NADH, are produced, but they do not contribute to FADH2 levels.

Thus, the correct option reflecting the total amount of FADH2 generated during aerobic respiration from one molecule of glucose is indeed 2.