I-L-Phenylalanine iyi-amino acid ebalulekile futhi iyisandulela se-amino acid tyrosine.Umzimba awukwazi ukwenza i-phenylalanie kodwa udinga i-phenylalanie ukuze ukhiqize amaprotheni.Ngakho, izidingo zomuntu zokuthola i-phenylalanie ekudleni.Izinhlobo ezi-3 ze-phenylalanie zitholakala emvelweni: i-D-phenylalanine, i-L-phenylalanine, ne-DL-phenylalanine.Phakathi kwalezi zinhlobo ezintathu, i-L-phenylalanine ifomu lemvelo elitholakala ekudleni okuningi okuqukethe amaprotheni, okuhlanganisa inyama yenkomo, izinkukhu, ingulube, inhlanzi, ubisi, iyogathi, amaqanda, ushizi, imikhiqizo ye-soy, namantongomane athile kanye nembewu.