Definition of ornithine in English:


Syllabification: or·ni·thine
Pronunciation: /ˈôrnəˌTHēn


  • An amino acid produced by the body that is important in protein metabolism.
    • Chemical formula: NH2(CH2)3CH(NH2)COOH
    More example sentences
    • About 50-percent of ingested arginine is rapidly converted in the body to ornithine, primarily by the enzyme arginase.
    • When your body doesn't digest protein completely, gut bacteria convert two of the amino acids in protein, arginine and ornithine, to compounds called polyamines.
    • This may occur in part as a result of pathologically elevated activity of arginase, an enzyme that hydrolyzes arginine to ornithine and urea.


late 19th century: from ornitho- (with reference to a constituent found in bird excrement) + -ine4.

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Pronunciation: ˌkɒlərəˈtjʊərə
elaborate ornamentation of a vocal melody