The oxygen-dependent reactions required for cellular respiration were originally thought to occur in a linear pathway.By using a competitive inhibitor for one enzyme in the pathway, investigators discovered that these reactions occur in a cycle.What compound served as the inhibitor?

Question

Quizplus · Accepted Answer

Malonate is a competitive inhibitor for the enzyme succinate dehydrogenase, which is part of the electron transport chain in cellular respiration. The fact that the inhibitor affects the pathway indicates that the reactions occur in a cycle rather than a linear pathway. Malate, fumarate, and succinate are all intermediates in the pathway and would not serve as effective inhibitors.

The Oxygen-Dependent Reactions Required for Cellular Respiration Were Originally Thought