What is the significance of FADH2 generated during the Citric Acid Cycle?

The significance of FADH2 generated during the Citric Acid Cycle lies primarily in its role as an electron carrier in the electron transport chain. FADH2 is produced during the oxidation of succinate to fumarate in the cycle. Once formed, FADH2 donates its high-energy electrons to the electron transport chain, specifically to complex II (succinate dehydrogenase).

The transfer of these electrons through the chain facilitates proton pumping across the mitochondrial membrane, creating an electrochemical gradient that is utilized by ATP synthase to generate ATP through oxidative phosphorylation. This process is crucial because it allows for the efficient production of ATP, the primary energy currency of the cell.

Furthermore, while FADH2 cannot directly convert to ATP, it plays a vital role in the overall yield of ATP during aerobic respiration, as each mole of FADH2 is responsible for generating approximately 1.5 moles of ATP through the subsequent processes of the electron transport chain. Therefore, the role of FADH2 as an electron carrier is central to energy production in cells during aerobic metabolism.