Glycine, a non-essential amino acid, has vital metabolic roles, including serving as a constituent of collagen, a one-carbon donor, and a precursor for purine nucleotides, bile salts, and heme. Clinically, defects in glycine metabolism can lead to conditions like hyperoxaluria, nonketotic hyperglycinemia, and glycinuria, contributing to significant health implications such as oxalate stone formation and neurological disorders.