Topic overview

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Glucogenic amino acids yield intermediates such as pyruvate, oxaloacetate, fumarate, α-ketoglutarate, and succinyl-CoA that can support gluconeogenesis. Ketogenic amino acids produce acetyl-CoA or acetoacetate, which can contribute to ketone bodies or lipids but cannot support net glucose synthesis. Leucine and lysine are exclusively ketogenic; isoleucine, phenylalanine, threonine, tryptophan, and tyrosine are both glucogenic and ketogenic. The topic also connects amino acid catabolism to clinical conditions, including phenylalanine hydroxylase deficiency and branched-chain α-ketoacid dehydrogenase deficiency. Pathways involving propionyl-CoA, niacin production from tryptophan, and the metabolic roles of leucine and lysine add further context.