Which molecule is NOT formed during the Citric Acid Cycle (CTA)?

During the Citric Acid Cycle (CAC), various key intermediates are produced through a series of enzymatic reactions that primarily occur in the mitochondria. The cycle begins with the combination of acetyl-CoA and oxaloacetate, leading to the formation of citrate. From there, citrate is converted through several steps into different intermediates, including malate, succinate, and α-ketoglutarate.

Malate is formed when fumarate is converted into malate, a step catalyzed by the enzyme fumarase. Succinate is produced from succinyl-CoA in a reaction catalyzed by succinate thiokinase, which also produces GTP or ATP. α-Ketoglutarate is generated from isocitrate through a decarboxylation reaction catalyzed by isocitrate dehydrogenase.

Phosphoenolpyruvate (PEP), however, is not a product of the Citric Acid Cycle at any point. Instead, it is a key intermediate in glycolysis and gluconeogenesis, specifically formed from 2-phosphoglycerate through the action of the enzyme enolase. Therefore, PEP is not associated with the CAC, making it the correct answer to the