What does methionine mean?
Methionine is an essential sulfur-containing amino acid, one of the building blocks of protein. Human beings and many other animals cannot synthesize it in sufficient amounts, so it must be supplied through food or supplements. Methionine is found especially in eggs, meat, fish, dairy products, legumes, nuts, and seeds, and it contributes to the characteristic odors of many sulfur-containing foods. In nutrition, it is often discussed as a potentially limiting amino acid because its abundance varies among plant and animal sources. Biochemists also study methionine because it participates in methylation reactions and in the metabolism of sulfur. Although the word may sound familiar mainly from supplements and specialized nutrition information, it has a precise role in describing both an essential nutrient and an important molecular compound.
nounAn essential amino acid containing sulfur, found in proteins and necessary for normal growth and metabolism. It is one of the eight essential amino acids for adults and must be obtained from the diet.
- A sulfur-containing essential amino acid that is a constituent of proteins and is required for growth and metabolism.
"Methionine is often described as a limiting amino acid in plant-based diets."
"Methionine is abundant in eggs, dairy products, meat, and legumes."
"The nutritionist explained that methionine is one of the essential amino acids the body cannot make on its own."
Usually used in the singular in biochemistry and nutrition; the plural is uncommon.
"The researchers compared the methionines obtained from the two protein sources."
Methionine is the amino acid that gives garlic, onions, and many other sulfur-containing foods their distinctive aroma.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does methionine come from?
The name methionine was formed within chemical nomenclature from elements referring to its methyl and sulfur-containing structure. Its ultimate association with Greek methion, meaning egg yolk, reflects the substance’s early association with egg yolk. The related English words methyl and methane come from a separate but etymologically related line through Greek methy, meaning alcohol or a fermented drink.
Related word forms
How methionine is actually used
In general usage, methionine is primarily a technical or nutritional term. It is also used in biochemistry to refer specifically to the amino acid and to related chemical compounds.