<prompt> Amino acid with double chiral carbon-TyrosineThreonineTryptophanPhenylalanine  <response>: All amino acids have 1 assymetric or chiral C means this C has all 4 valencies occupied by different atoms or group of atoms EXCEPTIONS: 0 - Glycine So it lacks chilarity. Hence glycine wont show any optical activity 2 - Isoleucine, Threonine double chiral carbons 