Glutamic acid is a non-essential amino acid central to protein synthesis, nitrogen metabolism, and the citric acid cycle via conversion to alpha-ketoglutarate. It functions as the primary excitatory neurotransmitter in the mammalian brain and is responsible for the savory umami taste in foods such as cheese, tomatoes, and fermented products. Industrially, its monosodium salt (MSG) is widely used as a flavor enhancer. The molecule contains two carboxylic acid groups and one amino group, conferring acidic properties (pKa values approximately 2.2, 4.3, and 9.7). It occurs naturally in proteins and is produced via bacterial fermentation for commercial use. In nutrition, it supports gut health and immune function.