<prompt> Sulphur containing amino acid isare -Aspartic acidGlutamineMethionineGlycine  <response>: Ans. is c i.e., Methionine o Based on chemical structure of side chain R, amino acids are classified into: -1 Aliphatic amino acids:- Alanine, glycine, isoleucine, leucine, valine.2 Hydroxy amino acids:- Serine, threonine, tyrosine.3 Sulfur containing amino acids:- Cysteine, methionine.4 Dicarboxylic amino acids:- Aspartic acid aspartate, glutamic acid glutamate.5 Amide containing amino acids:- Glutamine, aspargine these are amides of dicarboxylic amino acids. Glutamine is amide of glutamic acid and aspargine is amide of aspartic acid.6 Aromatic amino acids:- Phenylalanine, tyrosine, tryptophan.7 Imino acids or heterocyclic amino acids: - One of the 20 amino acids, proline is an imino -NH acid not an amino -NH2 acid, as are other 19. 