Glutamic acid, or glutamate, the salt form of glutamic acid, functions as a neurotransmitter and also serves as a precursor to other neurotransmitters such as γ-aminobutyric acid. Glutamic acid also plays a key role in many metabolic pathways, that controls growth, reproduction, maintenance and immunity. It is converted to α-ketoglutarate, a key component of the TCA (tricarboxylic acid) cycle, and a precursor for the biosynthesis of nucleic acids and certain amino acids. In cells, glutamine is converted to glutamate by the enzyme glutaminase.
