What type of reaction does isocitrate dehydrogenase catalyze?

Isocitrate dehydrogenase catalyzes an oxidative decarboxylation reaction. In this process, isocitrate undergoes oxidation, where it loses electrons, and simultaneously loses a carbon dioxide molecule. During the reaction, NAD+ is reduced to NADH, reflecting the transfer of electrons. The formation of NADH is a critical aspect of the citric acid cycle, as it serves as an energy-carrying molecule that will later contribute to ATP production in the electron transport chain.

This type of reaction is significant in the citric acid cycle because it is both a decarboxylation (removal of a carbon as CO2) and an oxidation (conversion of isocitrate to α-ketoglutarate), linking carbon metabolism with energy production. The correct identification of this enzyme’s activity underscores the interconnectedness of oxidation and decarboxylation in cellular respiration processes. Understanding this reaction is fundamental for grasping how cells convert the energy stored in nutrients into usable energy forms.