Aromatic Amino Acids z All very hydophobic z All contain aromatic group z Absorb UV at 280 nm z Phenylalanine(Phe, F) z Tyrosine(Tyr,Y) – -OH ionizable (pKa = 10.5), H-Bonding z Tryptophan(Trp, W) – bicyclic indole ring, H-BondingAromatic Amino Acids z All very hydophobic z All contain aromatic group z Absorb UV at 280 nm z Phenylalanine(Phe, F) z Tyrosine(Tyr,Y) – -OH ionizable (pKa = 10.5), H-Bonding z Tryptophan(Trp, W) – bicyclic indole ring, H-Bonding