What does lysine mean?
Lysine is an essential amino acid, one of the nine amino acids that the human body cannot make in sufficient amounts and therefore must obtain from food. It is a building block of proteins and a component of certain biomolecules, including collagen and carnitine, so adequate intake supports normal tissue formation and repair. In nutrition, lysine is discussed in terms of dietary requirements, food sources, fortification, and supplementation; in biochemistry and genetics, the term can also refer to a lysine residue within a protein. The word is technical but not obscure, appearing in product labels, clinical discussions, and discussions of plant-based diets, where it is often associated with grain-and-legume-based meals. Lysine was named from a Greek root associated with hydrolysis, reflecting its emergence from the study of protein breakdown. Its importance lies in being both biologically indispensable and familiar through everyday food and health language.
nounLysine is an essential amino acid and a building block of proteins, one of the nine amino acids that humans must obtain from their diet because the body cannot synthesize it in sufficient amounts. It is also found in certain biomolecules, including collagen and carnitine.
- An essential amino acid that serves as a building block of proteins and is required in human nutrition.
- In biochemistry or molecular biology, a lysine residue within a protein or peptide.
"Lysine is abundant in legumes, and its presence helps make a grain-and-legume meal a more complete source of protein."
"Lysine is one of the essential amino acids that the human body cannot make in sufficient amounts."
"The substitution of one amino acid for a lysine residue altered the protein's function."
The plural is rare. Lysine is usually used as a mass noun for the amino acid or nutrient, while the plural may refer to distinct lysine molecules or residues.
"The protein sequence contains three lysines within its active region."
Lysine is one of the nine essential amino acids the body cannot make itself—a small part of the alphabet with a major job in every cell.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does lysine come from?
Lysine was named in the 19th century from Greek lysis, meaning a loosening or dissolution, together with the chemical suffix -ine. The name referred to its emergence from the hydrolysis of protein-rich material. English later adopted the term with other chemical names ending in -ine, while derivatives such as lysate and lysosome continued the related Greek root.
Related word forms
How lysine is actually used
The word is primarily used in biochemistry, nutrition, genetics, and related technical fields. As a dietary nutrient, lysine is normally treated as a mass noun; when referring to individual residues or molecules, the plural 'lysines' is grammatically possible but uncommon.
Easily confused with lysine
Leucine is a different essential amino acid, so the two names should not be used interchangeably in nutritional or biochemical descriptions.