Match the Column I with column II : 

a-4, b-1, c-2 , d-3

The correct answer is Option (3) - a-4, b-1, c-2 , d-3

The chemical and physical properties of amino acids are essentially of the amino, carboxyl and the R functional groups. Based on number of amino and carboxyl groups, there are acidic (e.g.,glutamic acid and aspartic acid), basic (lysine and arginine.) and neutral (alanine, glycine, valine.) amino acids. Similarly, there are aromatic amino acids (tyrosine, phenylalanine, tryptophan). A particular property of amino acids is the ionizable nature of –NH₂ and –COOH groups. Hence in solutions of different pH, the structure of amino acids changes.