Ketogenic amino acid

A ketogenic amino acid is an amino acid that can be degraded directly into acetyl-CoA, which is the precursor of ketone bodies. This is in contrast to the glucogenic amino acids, which are converted into glucose. Ketogenic amino acids are unable to be converted to glucose as both carbon atoms in the ketone body are ultimately degraded to carbon dioxide in the citric acid cycle.

In humans, two amino acids are exclusively ketogenic:

(remembered as all the "L" amino acids)

• Leucine
• Lysine

In humans, five amino acids are both ketogenic and glucogenic:

(remembered by the useful mnemonic "PITTT" or "FITTT", and includes all the "T" amino acids)

• Isoleucine
• Phenylalanine (abbreviated Phe or F, in contrast to Proline which is Pro or P, based on their respective pronunciations)
• Threonine
• Tryptophan
• Tyrosine

In humans, the remaining thirteen amino acids are exclusively glucogenic (i.e. are not ketogenic).

See also

• Glucogenic amino acid
• List of standard amino acids
• Ketogenesis
• Metabolism

External links

• Amino acid metabolism
• Chapter on Amino acid catabolism in Biochemistry by Jeremy Berg, John Tymoczko, Lubert Stryer. Fourth ed. by Lubert Stryer. ISBN 0-7167-4955-6 Accessed 2007-03-17
• Amino acid metabolism