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[trip-tuh-fan] /ˈtrɪp təˌfæn/
noun, Biochemistry.
an essential amino acid, (C 8 H 6 N)CH 2 CH(NH 2)COOH, colorless, crystalline, and aromatic, released from proteins by tryptic digestion and a precursor of serotonin. Symbol: W.
Abbreviation: Trp;
Also, tryptophane
[trip-tuh-feyn] /ˈtrɪp təˌfeɪn/ (Show IPA)
Origin of tryptophan
1900-05; trypto- (irregular combining form representing Greek trīptós rubbed) + -phan(e) Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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British Dictionary definitions for tryptophan


an essential amino acid; a component of proteins necessary for growth
Word Origin
C20: from trypt(ic) + -o + -phan variant of -phane
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
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Word Origin and History for tryptophan

also tryptophane, complex amino acid, 1890, coined in German from trypto-, taken as a comb. form of tryptic "by trypsin," + Greek phainein "to appear" (see phantasm).

Online Etymology Dictionary, © 2010 Douglas Harper
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tryptophan in Medicine

tryptophan tryp·to·phan (trĭp'tə-fān') or tryp·to·phane (-fān')
Abbr. Try
An essential amino acid formed from proteins during the digestive process by the action of proteolytic enzymes.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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tryptophan in Science
An essential amino acid. Chemical formula: C11H12N2O2. See more at amino acid.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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