Chemistry - Biomolecules Question with Solution | TestHub

A. The pH at which Anion = Cation is called isoelectric point. At isoelectric point,$\mathrm{\alpha }$-amino acids do not migrate when electric field is applied.

B.$-\mathrm{S}{\mathrm{O}}_3\mathrm{H}$is strongly acidic and donates${\mathrm{H}}^{+}$to weakly basic arylamino group. ArCOOH is not acidic enough to transfer${\mathrm{H}}^{+}$to the arylamino group.

C. In$\mathrm{p}-{\mathrm{H}}_3\stackrel{+}{\mathrm{N}}{\mathrm{C}}_6{\mathrm{H}}_4\mathrm{S}{\mathrm{O}}_3,{\mathrm{H}}_3\stackrel{+}{\mathrm{N}}$is acid enough to transfer${\mathrm{H}}^{+}$to bases to give the soluble anion,$\mathrm{p}-{\mathrm{H}}_2\mathrm{N}-{\mathrm{C}}_6{\mathrm{H}}_4\mathrm{S}{\mathrm{O}}_3.-\mathrm{S}{\mathrm{O}}_3$is too feebly basic and cannot accept${\mathrm{H}}^{+}$from acids.

D.$\mathrm{\alpha }\text{-}{\text{H}}_3\stackrel{+}{\mathrm{N}}$group increases acidity, because of its electron-withdrawing inductive effect.