谷氨酸（麸氨酸）,α-氨基戊二酸是组成生物体内各种蛋白质的20种氨基酸之一。

Glutamic acid (abbreviated as Glu or E; encoded by the codons GAA or GAG) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH₃ form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO form under biological conditions), and a side chain carboxylic acid, classifying it as a polar negatively charged (at physiological pH), aliphatic amino acid. It is non-essential in humans, meaning the body can synthesize it.