<biochemistry> A class of organic molecules that containing an amino group and can combine in linear arrays to form proteins in living organisms.

There are twenty common amino acids: alanine, arginine, aspargine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine.

They are key components in all living things from which proteins are synthesised by formation of peptide bonds during ribosomal translation of messenger RNA.

All the amino acids have the L configuration, except glycine which is not optically active. Other amino acids occurring in proteins, such as hydroxyproline in collagen, are formed by post translational enzymatic modification of amino acid residues in polypeptide chains.

There are also several important amino acids, such as the neurotransmitter y aminobutyric acid, that have no relation to proteins.

Amino acids can now be produced by biotechnology in bulk using fermentation and biotransformation.

Acronym: AA

(13 Nov 1997)