Glycine is one of the 20 common amino acids found in proteins. In mammals, glycine is a non-essential amino acid, meaning it does not need to be present in the diet.

Glycine has the smallest functional group (hydrogen) of any of the amino acids.

One Letter Code	Three Letter Code	Molecular Wt. (Daltons)	Genetic Code Codons
G	GLY	57.06	GGU, GGC, GGA, GGG

Glycine is an allosteric inhibitor of glutamine synthetase, an enzyme with a central role in nitrogen metabolism in the cell.