Zwitter ion : In aqueous solution of amino acids, the carboxyl group can lose a proton and amino acid can accept that portion to from a dipolar ion. This ion is called as zwitter ion .
`R-undersetoverset(|)(underset(..)NH_2)(CH)-oversetunderset(||)(O)C-OHiffR-undersetoverset(|)(underset("zwitter ion")(+NH_3))(CH)-oversetunderset(||)(O)(C)-O^-`
