The melting points and solubility in water of amino acids are generally higher than that of the corresponding halo acids. Explain.

Options

A. amino acids exist as zwitter ions resulting in strong dipole-dipole attraction
B. amino acids are optically active
C. due to higher molecular mass of -`NH_(2)` group molecular mass of amino acids is higher
D. they interact with water more than halo-acids and have salt like structure .

Answer

A

Explanation

Amino acids exist as zwitter ions, `H_(3)overset(+)N-CHR-COO^(-)` .Because of this dipolar salt-like character, they have strong dipole-dipole attractions . Hence, their melting points are higher than halo-acids .