Sistin √ × Glutamat √ × Glutamin √ × Glisin √ × Prolin √ × Serin √ × Histidin √ × Metionin √ × Treonin √ × Valin √ × Tirosin √ √ Isoleusin √ √ Fenilalanin √ √ Triptofan √ √ Leusin × √ Lisin × √ Sumber: Hames dan Hooper (2005) 11