Amino acid with double chiral carbon-: (A) Tyrosine, (B) Threonine, (C) Tryptophan, (D) Phenylalanine
Answer is B. 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 won't show any optical activity) * 2 - Isoleucine, Threonine (double chiral carbons)