Glutamine is an amino acid found in proteins. In mammals, glutamine is a non-essential amino acid, meaning it does not need to be present in the diet. Glutamine is classified as an amide because it is an amide derivative of glutamic acid (Reaction 1 below). Glutamine is a very important compound in transamination reactions.

Reactions involving glutamine:

1. -Ketoglutarate + Glutamine + NADPH + H⁺ <=> 2 Glutamate +  NADP⁺ (Catalyzed by Glutamate Synthase)

2. Fructose-6-Phosphate + Glutamine <=> Glucosamine-6-Phosphate + Glutamate (catalyzed by Glutamine:Fructose-6-Phosphate Amidotransferase)

3. UTP + ATP + Glutamine <=> CTP + ADP + Glutamate + Pi (catalyzed by CTP Synthetase)

4. Glutamate + NH3 + ATP -> Glutamine + ADP + Pi (catalyzed by Glutamine Synthetase)

One Letter Code	Three Letter Code	Molecular Wt. (Daltons)	Genetic Code Codons
Q	GLN	128.14	CAA, CAG