What would be the consequence of a deficiency in succinate dehydrogenase?

A deficiency in succinate dehydrogenase would lead to impaired electron transport and lower ATP production. Succinate dehydrogenase is a critical enzyme in the citric acid cycle, specifically catalyzing the conversion of succinate to fumarate while reducing ubiquinone to ubiquinol in the electron transport chain.

When succinate dehydrogenase is deficient, this enzymatic reaction is compromised, leading to decreased production of fumarate and reduced availability of reduced ubiquinone. As a result, the electron transport chain is less efficient, which directly impacts ATP synthesis since this process relies on the flow of electrons to pump protons across the mitochondrial membrane, creating a proton gradient necessary for ATP synthase to generate ATP.

Therefore, the deficiency disrupts both the citric acid cycle and the related oxidative phosphorylation processes, collectively resulting in lower ATP production and compromised cellular energy metabolism.