2-Ketoglutaric acid (alpha-ketoglutarate) is a key molecule in the TCA cycle, playing a fundamental role in determining the overall rate of this important metabolic process. In the TCA cycle, AKG is decarboxylated to succinyl-CoA and carbon dioxide by AKG dehydrogenase, which functions as a key control point of the TCA cycle. 2-Ketoglutaric acid is a reversible inhibitor of tyrosinase.