Chemistry - Biomolecules Question with Solution | TestHub

At low pH (acidic solution)$\mathrm{C}\mathrm{O}{\mathrm{O}}^{-}$ion acts as the base and accepts proton to form the cation.

$\underset{\text{Zwitter}\text{ion}}{{\text{H}}_3\stackrel{+}{\text{N}}-\stackrel{\text{H}}{\stackrel{|}{\underset{\text{R}}{\underset{|}{\text{C}}}}}-\stackrel{\text{O}}{\stackrel{\left|\right|}{\text{C}}}-{\text{O}}^{-}}\stackrel{\text{In acidic} \text{medium}}{\to }\underset{\text{Cation}}{{\text{H}}_3\stackrel{+}{\text{N}}-\stackrel{\text{H}}{\stackrel{|}{\underset{\text{R}}{\underset{|}{\text{C}}}}}-\stackrel{\text{O}}{\stackrel{\left|\right|}{\text{C}}}-\text{OH}}$