What does succinate dehydrogenase do during the citric acid cycle?

Succinate dehydrogenase plays a crucial role in the citric acid cycle by catalyzing the conversion of succinate to fumarate. This reaction is significant because it represents one of the key steps in the cycle where a substrate-level oxidation occurs. During this process, succinate is oxidized, and the electrons released are transferred to the electron carrier molecule FAD, which is reduced to FADH2. This step is essential for the continuation of the cycle and contributes to the overall production of energy by facilitating the flow of electrons into the electron transport chain later in cellular respiration.

The conversion of succinate to fumarate is important not just for the cycle itself but also for the production of reduced coenzymes that are later used to generate ATP. Understanding this reaction helps in grasping how the citric acid cycle connects with the broader energy-generating processes in the cell.