Question

The increasing order of pKa of the following amino acids in aqueous solution is :

Gly Asp Lys Arg

(1) Asp < Gly < Arg < Lys

(2) Arg < Lys < Gly < Asp

(3) Gly < Asp < Arg < Lys

(4) Asp < Gly < Lys < Arg