a-ketoglutaric acid

A five-carbon dicarboxylic keto acid with the formula HOOCCO(CH₂)₂COOH. α-ketoglutarate is an intermediate in the *TCA cyce. It is formed by the oxidation of isocitrate, with the concomitant reduction of NAD to NADH. In the next step of the TCA cycle α-ketoglutarate undergoes oxidative decarboxylation to form succinyl CoA in a reaction similar to the formation of acetyl CoA from pyruvate. α-ketoglutarate is also involved in amino acid metabolism (see transamination ).