Definition of tryptophan in English:



mass nounBiochemistry
  • An amino acid which is a constituent of most proteins. It is an essential nutrient in the diet of vertebrates.

    An indole derivative; chemical formula: C₈H₆NCH₂CH(NH₂)COOH

    • ‘Key essential amino acids are valine, leucine, isoleucine, tryptophan and methionine.’
    • ‘Two known enzymes catabolize the essential amino acid tryptophan in mammals.’
    • ‘For example, eggs are high in alanine and methionine; whey protein is high in tryptophan and threonine.’
    • ‘Negative dietary changes are related to the deficiency of maize in the amino acids tryptophan and lysine.’
    • ‘Peptides are named by the position of tryptophan in the amino acid sequence.’


Late 19th century from tryptic ‘relating to trypsin’ + Greek phainein ‘appear’.