<prompt> Acidic amino acids are -AsparagineArginineNoneLysine  <response>: Proline is a unique amino acid and has an immino group NH instead of an amino NH2 group found in other amino acid. Methionine Cysteine are sulfur containing aminoacids. The propey of photochromicity i.e. absorbance of ultraviolet light at 250-290nm esp 280nm is seen with aromatic amino acid tryptophan tyrosine phenylalanine. Hydrophobic non polar aminoacids have no charge on their R group or side chain. Aliphatic eg methyl, methylene, thioether imino side chains and aromatic side chains are nonpolar. So methyl CH3 side chain of alanine; propyl C3H7 side chain of valine; butyl C4H9 side chain of leuicine isoleucine; thioether side chain of methionine; and imino group pyrrolidine containing side chain of proline are nonpolar. Methyl CH3 side chain of alanine is nonpolar. Serine, threonine, tyrosine containing hydroxyl group and cysteine containing sulfhydryl group, are polar aminoacids with neutralunchargednonionic side chain. Positively charged basic amino NH 3group side chain of histidine, arginine and lysine ; and negatively acidic carboxyl COO- side chain of aspaic acid and glutamic acid is polar. 