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[loo-seen, -sin] /ˈlu sin, -sɪn/
noun, Biochemistry.
a white, crystalline, water-soluble amino acid, C 6 H 13 NO 2 , obtained by the decomposition of proteins and made synthetically: essential in the nutrition of humans and animals. Symbol: L.
Abbreviation: Leu;
Origin of leucine
First recorded in 1820-30; leuc- + -ine1 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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Examples from the Web for leucine
Historical Examples
  • An experiment carried out as above without any addition of leucine gave 9732 grams of alcohol containing 040 per cent.

    Alcoholic Fermentation Arthur Harden
British Dictionary definitions for leucine


an essential amino acid found in many proteins
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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leucine in Medicine

leucine leu·cine (lōō'sēn')
Abbr. Leu
An essential amino acid derived from the hydrolysis of protein by pancreatic enzymes during digestion and necessary for optimal growth in infants and children and for the maintenance of nitrogen balance in adults.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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leucine in Science
An essential amino acid. Chemical formula: C6H13NO2. See more at amino acid.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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