What does glycine mean?
Glycine is an amino acid, one of the molecular building blocks from which proteins are made. It is notable as the simplest of the standard amino acids because its side chain consists of only a hydrogen atom. Beyond its role in proteins, glycine acts as an inhibitory neurotransmitter: released by nerve cells, it activates glycine receptors and helps reduce the likelihood of further nerve signals. Glycine also occurs naturally in many foods and is sold as a dietary supplement, sometimes in powdered or free-form form. Its use is especially associated with nutrition, biochemistry, pharmacology, and research on nervous-system signaling. The name derives from a Greek root meaning “sweet,” a reference to the substance's sweet taste. Although less familiar than amino acids such as lysine or tryptophan, glycine is both structurally distinctive and physiologically important. Understanding it is useful for anyone studying metabolism, protein structure, supplements, or the function of the brain and spinal cord.
nounA naturally occurring amino acid and protein building block whose side chain is a single hydrogen atom, making it the simplest of the standard amino acids.
- The amino acid glycine, a naturally occurring constituent of proteins that also functions as an inhibitory neurotransmitter in the nervous system.
"The laboratory synthesized glycine from ammonia and formaldehyde using a new catalytic process."
"The athlete's recovery drink contained glycine, which is sometimes used in dietary supplements."
"Glycine binds to receptors in the spinal cord and brain, helping inhibit nerve signals."
The plural is uncommon; scientific writing usually uses “molecules of glycine” or simply “glycine” when referring to the substance generally.
"The two glycines occupy different positions within the protein's folded structure."
Glycine literally named itself: its name comes from the Greek word for “sweet,” reflecting the taste that helped early scientists identify it.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does glycine come from?
The English name comes through French from a New Latin scientific formation based on Greek glykys, meaning “sweet.” The chemical ending -ine was added in accordance with contemporary naming conventions for organic substances. The “sweet” root is shared by words such as glucose, glycogen, glycoside, and glycolysis, and glycine was named for its characteristic sweet taste.
How glycine is actually used
Glycine is primarily a scientific, biochemical, nutritional, and medical term. It is encountered in discussions of amino acids, proteins, neurotransmitters, food additives, and dietary supplements, with no significant British–US difference.
Easily confused with glycine
Glycine is an amino acid used in proteins and neurotransmission, whereas glycogen is a carbohydrate that stores glucose in animals and fungi.
Both are amino acids, but glycine has only a hydrogen atom as its side chain, while serine has a hydroxyl-containing side chain.