Production:

Glycine is manufactured industrially by treating chloroacetic acid with ammonia:[4]

ClCH2COOH + 2 NH3 → H2NCH2COOH + NH4Cl

It is also produced via the Strecker amino acid synthesis.

Biosynthesis:

Glycine is not essential to the human diet, as it is biosynthesized in the body from the amino acid serine, which is in turn derived from 3-phosphoglycerate. In most organisms, the enzyme Serine hydroxymethyltransferase catalyses this transformation via the cofactor pyridoxal phosphate:[5]

serine + tetrahydrofolate → glycine + N5,N10-Methylene tetrahydrofolate + H2O

In the liver of vertebrates, glycine synthesis is catalyzed by glycine synthase (also called glycine cleavage enzyme). This conversion is readily reversible:[5]

CO2 + NH4+ + N5,N10-Methylene tetrahydrofolate + NADH + H+ → Glycine + tetrahydrofolate + NAD+