This document summarizes information about glycine, the smallest amino acid. It discusses glycine's structure and functions, which include involvement in motor control, pain perception, and enhancing antioxidants. Glycine acts as an inhibitory neurotransmitter and is synthesized through various pathways in the body. It is stored in synaptic vesicles and binds to both alpha and beta receptor subtypes. The document outlines glycine's metabolism, reuptake, and interactions with agonists and antagonists. It concludes by discussing metabolic disorders related to glycine like hyperekplexia and glycinuria.