[ tahy-ruh-seen, -sin, tir-uh- ]
/ ˈtaɪ rəˌsin, -sɪn, ˈtɪr ə- /

noun Biochemistry.

a crystalline amino acid, HOC6H4CH2CH(NH2)COOH, abundant in ripe cheese, that acts as a precursor of norepinephrine and dopamine. Abbreviation: Tyr; Symbol: Y

Origin of tyrosine

1855–60; < Greek tȳrós cheese + -ine2
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for tyrosine

  • Both the tyrosine and tryptophane may be either in the free state or in combination as polypeptid or peptone.

  • This reaction is caused by the tyrosine group (p. oxy α amido phenyl-propionic acid).

    Animal Proteins|Hugh Garner Bennett

British Dictionary definitions for tyrosine


/ (ˈtaɪrəˌsiːn, -sɪn, ˈtɪrə-) /


an aromatic nonessential amino acid; a component of proteins. It is a metabolic precursor of thyroxine, the pigment melanin, and other biologically important compounds

Word Origin for tyrosine

C19: from Greek turos cheese + -ine ²
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for tyrosine


[ tīrə-sēn′ ]


A white crystalline amino acid that is derived from the hydrolysis of proteins such as casein and is a precursor of epinephrine, thyroxine, and melanin.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for tyrosine


[ tīrə-sēn′ ]

A nonessential amino acid. Chemical formula: C9H11NO3. See more at amino acid.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.