Phenylalanine

Phenylalanine (Phe or F) is an amino acid present in proteins.

Structure of phenylalanine

Like all of the amino acids, phenylalanine has two functional groups, an amine group (NH₂) and a carboxyl group (COOH). Its side chain consists of a benzene ring attached to the central carbon atom by a CH₂group. It is a non-polar, aromatic, amino acid.

Function of phenylalanine

Phenylalanine is an essential amino acid which is not produced by the body and which must therefore be provided in the diet.

It is a precursor of tyrosine, another amino acid and also of hormones such as adrenaline, noradrenaline and melanin.

Along with aspartic acid it makes up the dipeptide aspartame which is widely used for its sweetening action.