An amino acid under certain conditions have both positive and negative charges simultaneously in the same molecule. Such a form of amino acid is called

Options

A. acidic form
B. basic form
C. aromatic form
D. zwitterionic form

Answer

D

Explanation

A zwitterion is a neutral molecule having both the cationic and anionic charges on the same molecule. Amino acids are the best known examples of zwitterion. In acidic solution' amino group accepts a hydrogen ion to become positively charged. Whereas, in alkaline solution the carboxyl group donates a hydrogen ion to become negatively charged. The pH at which the amino acid is electrically neutral is called isoelectric pH.
`underset(("low pH"))underset("Cation")underset()(NH_(3)-overset(R)CH-COOH)hArr^(+)underset(("Zwitterion at isoelectric pH"))underset()(H_(3)N-overset(R)CH-COO^(-))hArrunderset(("high pH"))underset("Anion")underset()(H_(2)N-overset(R)CH-COO^(-))`