Glutamic acid exists in two optically isomeric forms; the dextrorotatory L-form is usually obtained by hydrolysis of gluten or from the waste waters of beet-sugar manufacture or by fermentation.

However, in the solid state and mildly acidic water solutions, the molecule assumes an electrically neutral zwitterion structure −OOC−CH(NH+3)−(CH2)2−COOH.

The acid can lose one proton from its second carboxyl group to form the conjugate base, the singly-negative anion glutamate −OOC−CH(NH+3)−(CH2)2−COO−.

In sufficiently acidic environments, both carboxyl groups are protonated and the molecule becomes a cation with a single positive charge, HOOC−CH(NH+3)−(CH2)2−COOH.

The substance was discovered and identified in the year 1866 by the German chemist Karl Heinrich Ritthausen, who treated wheat gluten (for which it was named) with sulfuric acid.

[14] In 1908, Japanese researcher Kikunae Ikeda of the Tokyo Imperial University identified brown crystals left behind after the evaporation of a large amount of kombu broth as glutamic acid.

[18] Chemical synthesis was supplanted by the aerobic fermentation of sugars and ammonia in the 1950s, with the organism Corynebacterium glutamicum (also known as Brevibacterium flavum) being the most widely used for production.

In humans, dietary proteins are broken down by digestion into amino acids, which serve as metabolic fuel for other functional roles in the body.

Examples are as follows: Both pyruvate and oxaloacetate are key components of cellular metabolism, contributing as substrates or intermediates in fundamental processes such as glycolysis, gluconeogenesis, and the citric acid cycle.

[24] The form of plasticity known as long-term potentiation takes place at glutamatergic synapses in the hippocampus, neocortex, and other parts of the brain.

[25] In addition, glutamate plays important roles in the regulation of growth cones and synaptogenesis during brain development as originally described by Mark Mattson.

[27] This raises the possibility that this extracellular glutamate plays an "endocrine-like" role as part of a larger homeostatic system.

[28] GABA-ergic neurons are identified (for research purposes) by revealing its activity (with the autoradiography and immunohistochemistry methods)[29] which is most abundant in the cerebellum and pancreas.

All meats, poultry, fish, eggs, dairy products, and kombu are excellent sources of glutamic acid.

A glutamic acid derivative, poly-γ-benzyl-L-glutamate (PBLG), is often used as an alignment medium to control the scale of the dipolar interactions observed.

[34] The drug phencyclidine (more commonly known as PCP or 'Angel Dust') antagonizes glutamic acid non-competitively at the NMDA receptor.

Acute infusion of the drug eglumetad (also known as eglumegad or LY354740), an agonist of the metabotropic glutamate receptors 2 and 3) resulted in a marked diminution of yohimbine-induced stress response in bonnet macaques (Macaca radiata); chronic oral administration of eglumetad in those animals led to markedly reduced baseline cortisol levels (approximately 50 percent) in comparison to untreated control subjects.