The first 5-C dicarboxylic acid in Krebs' cycle which is used in nitrogen metabolism is ____.

Step-by-step solution

The TCA cycle or the Kreb's cycle is a form of aerobic respiration where the reaction starts with the acetyl group condensation by oxaloacetic acid and water, whose product is citric acid. The citrate is then isomerised to isocitrate followed by successive steps of decarboxylation. The first step of decarboxylation leads to the formation of a 5-C dicarboxylic acid, the α -ketoglutaric acid which is used in nitrogen metabolism as a precursor for many amino acids and purines.