Phosphoenolpyruvic acid plays a role in both glycolysis and gluconeogenesis. During glycolysis, it is formed by the action of enolase on 2-phosphoglycerate and is metabolized to pyruvate by pyruvate kinase. One molecule of ATP is formed during its metabolism in this pathway. During gluconeogenesis, it is formed from phosphoenolpyruvate carboxykinase-catalyzed oxaloacetate decarboxylation and GTP hydrolysis. In plants, it is metabolized to form aromatic amino acids and also serves as a substrate for phosphoenolpyruvate carboxylase-catalyzed carbon fixation.
