Noun
an amino acid that is required by animals but that they cannot synthesize; must be supplied in the diet
Source: WordNetBiosynthesis As an essential amino acid, phenylalanine is not synthesized de novo in humans and other animals, who must ingest phenylalanine or phenylalanine-containing proteins. Source: Internet
Biosynthesis Methionine biosynthesis As an essential amino acid, methionine is not synthesized de novo in humans and other animals, who must ingest methionine or methionine-containing proteins. Source: Internet
Phenylalanine and phenylketonuria High levels of the naturally-occurring essential amino acid phenylalanine are a health hazard to those born with phenylketonuria (PKU), a rare inherited disease that prevents phenylalanine from being properly metabolized. Source: Internet
This essential amino acid is classified as neutral, and nonpolar because of the inert and hydrophobic nature of the benzyl side chain. Source: Internet
Cooking also increases protein digestibility, essential amino acid index, and protein efficiency ratio. Source: Internet
In plants, the parent amino acid L-tryptophan is produced endogenously where in animals L-tryptophan is an essential amino acid coming from diet. Source: Internet