An amino acid which is a constituent of most proteins. It is an essential nutrient in the diet of vertebrates.
- ‘For example, eggs are high in alanine and methionine; whey protein is high in tryptophan and threonine.’
- ‘Peptides are named by the position of tryptophan in the amino acid sequence.’
- ‘Key essential amino acids are valine, leucine, isoleucine, tryptophan and methionine.’
- ‘Two known enzymes catabolize the essential amino acid tryptophan in mammals.’
- ‘Negative dietary changes are related to the deficiency of maize in the amino acids tryptophan and lysine.’
Late 19th century: from tryptic ‘relating to trypsin’ + Greek phainein ‘appear’.
We take a look at several popular, though confusing, punctuation marks.