Definition of leucine in English:

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Pronunciation: /ˈlo͞osən/
Pronunciation: /ˈlo͞oˌsēn/


A hydrophobic amino acid that is a constituent of most proteins. It is an essential nutrient in the diet of vertebrates.
  • Chemical formula: (CH3)2CHCH2CH(NH2)COOH.
Example sentences
  • The aspartate can be used as a precursor for the synthesis of other amino acids such as asparagine, threonine, isoleucine, leucine, valine, lysine, and methionine.
  • Key essential amino acids are valine, leucine, isoleucine, tryptophan and methionine.
  • In simple terms, BCAAs are made up of three amino acids: leucine, isoleucine and valine.


Early 19th century: coined in French from Greek leukos 'white' + -ine4.

For editors and proofreaders

Syllabification: leu·cine

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