Methionine (Met or M) is an amino acid present in proteins.
Structure of methionine
Like all of the amino acids, methionine has two functional groups, an amine group (NH2) and a carboxyl group (COOH). It has a relatively long side chain: CH2-CH2-S-CH3. and is a non-polar amino acid.
Function of methionine
Methionine is an essential amino acid which is obtained from the diet (seeds, meat, fish).
It is a specific amino acid in that it is the first one to be incorporated into protein chains by the ribosome. Methionine is only coded for by a single codon (AUG, in the universal gene code) on the messenger RNA,
Methionine is an essential amino acid. © Ben Mills, Wikimedia, public domain