NH3CH2COO

NH3CH2COO describes the zwitterionic form of glycine, the simplest amino acid and a fundamental building block of proteins. In this form the molecule carries both a positive and a negative charge, commonly depicted as H3N+-CH2-COO−, with the molecular formula C2H5NO2 and a molecular weight of 75.07 g/mol. The zwitterion is the dominant species at physiological pH (around 7.4) and near the amino acid’s isoelectric point, which is about 5.97. At very low pH glycine adopts the fully protonated form H3N+-CH2-COOH, while at high pH it becomes NH2-CH2-COO−.

Glycine is encoded genetically and occurs in proteins; it is nonessential in humans, being synthesizable from other metabolites. In metabolism it participates in the synthesis of purines and porphyrins and contributes to one-carbon metabolism through glycine cleavage and serine hydroxymethyltransferase pathways. Beyond its biological role, glycine is used as a buffering agent in biochemical methods and as a precursor or component in peptide synthesis. It is widely employed in laboratory settings and in various industrial and pharmaceutical contexts, and is generally regarded as non-toxic.