It is a five-carbon compound of the Krebs cycle:

Explanation

Alpha-ketoglutarate, also known as 2-oxoglutarate, is a key intermediate in several metabolic pathways, including the citric acid cycle (also known as the Krebs cycle or tricarboxylic acid cycle) and amino acid metabolism. It is a five-carbon compound with a keto group (C=O) at the second carbon.It is a five-carbon compound with a keto group (C=O) at the second carbon.: In the citric acid cycle, alpha-ketoglutarate is produced by the decarboxylation of isocitrate.