phenylalanine
phe·nyl·al·a·nine
noun \ˌfen-əl-ˈal-ə-ˌnēn, ˌfēn-\Definition of PHENYLALANINE
: an essential amino acid C9H11NO2 that is obtained in its levorotatory L-form by the hydrolysis of proteins (as lactalbumin), that is essential in human nutrition, and that is converted in the normal body to tyrosine—abbreviation Phe; see phenylketonuria, phenylpyruvic acid
