Amino acid in Zwitter ionic form shows

Acid behaviour Basic behaviour Amphoteric behaviour Neutral behaviour

Amphoteric behaviour

Amino acids have an amino (-NH2) group, basic in nature, and accept proton and COOH group loses a proton forming a dipolar ion called the Zwitter ion. In this form, amino acids behave as acids and bases so they are amphoteric. Example: Glycine Pure glycine, however, exists as a Zwitter ion: