Glycine exist as a dipolar ion, while anthranilic acid does not. Explain.

Compound $\left(\mathrm{A}\right)$, ${\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6$, is oxidized by bromine water into a monobasic acid and also reduces Tollen's reagent and Fehling's solution. It also responds to the following reactions. Identify the compound $\left(\mathrm{A}\right)$.