[tahy-ruh-seen, -sin, tir-uh-]
noun Biochemistry.
a crystalline amino acid, HOC 6 H 4 CH 2 CH(NH 2 )COOH, abundant in ripe cheese, that acts as a precursor of norepinephrine and dopamine. Abbreviation: Tyr; Symbol: Y

1855–60; < Greek tȳrós cheese + -ine2

Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To tyrosine
World English Dictionary
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
[C19: from Greek turos cheese + -ine²]

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Word Origin & History

amino acid, 1857, coined 1846 by Ger. chemist Baron von Justus Liebig (1802-73) from Gk. tyros "cheese" + chemical suffix -ine. So called because it was easily obtained from cheese.
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
American Heritage
Medical Dictionary

tyrosine ty·ro·sine (tī'rə-sēn')
Abbr. Tyr
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.
Cite This Source
American Heritage
Science Dictionary
tyrosine   (tī'rə-sēn')  Pronunciation Key 
A nonessential amino acid. Chemical formula: C9H11NO3. See more at amino acid.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Example sentences
Tyrosine kinase inhibitor drugs block proteins involved in tumor cell growth and production.
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature