Glycine is the simplest amino acid and plays a crucial role in the synthesis of proteins. It is classified as a non-essential amino acid, meaning the body can produce it on its own. Glycine is found in various foods, particularly in high-protein sources like meat, fish, dairy, and legumes. In addition to its role in protein synthesis, glycine is important for the production of collagen, a protein that supports skin, bones, and connective tissues. It also acts as a neurotransmitter in the central nervous system, contributing to various functions, including sleep regulation and cognitive processes.