Which intermediate is formed directly after citrate in the Citric Acid Cycle?

The intermediate formed directly after citrate in the Citric Acid Cycle is isocitrate. This transformation occurs through the enzyme aconitase, which catalyzes the conversion of citrate into isocitrate via an intermediate known as cis-aconitate. Isocitrate is then further processed in the cycle, leading to the production of alpha-ketoglutarate. This step is crucial as it sets the stage for subsequent reactions in the cycle that contribute to cellular respiration and energy production.

Citrate itself is formed from the reaction of acetyl-CoA with oxaloacetate, marking the beginning of the cycle. Following the formation of citrate, its conversion to isocitrate is a key step in the metabolism of carbohydrates and fats. Understanding this process is essential, as isocitrate undergoes further decarboxylation and oxidation to eventually produce energy carriers like NADH and FADH2, which are vital for the electron transport chain.