An essential amino acid occurring naturally in the L-form, which is the active form. It is found in eggs, milk, gelatin, and other proteins.
A crystalline, a-amino acid considered essential for normal growth of animals. It is biosynthesized (i.e., made) from aspartic acid and is a precursor of isoleucine in microorganisms.
An essential four-carbon amino acid having a hydroxyl group attached to carbon 3.
Threonine is an essential amino acid containing a hydroxyl group. Threonine is required for the formation of the body’s proteins. Potential ergogenic roles of threonine supplementation have not been identified.