Glycine exists as `H_3N^(+)CH_(2)COO^(-)` while anthra-nilic acid, `p-NH_2-C_6H_4COOH` does not exist as dipolar ion.

Explanation

To explain why glycine exists as a dipolar ion while anthranilic acid does not, we can break down the reasoning into several steps:

### Step 1: Understanding Glycine Structure
Glycine is the simplest amino acid with the formula `H2NCH2COOH`. It contains both an amino group (`-NH2`) and a carboxyl group (`-COOH`).

### Step 2: Formation of Zwitterion
In solution, glycine can exist in a dipolar ion form, known as a zwitterion. This occurs when the amino group accepts a proton (H+) from the carboxyl group, resulting in the structure:
- The amino group becomes positively charged (`H3N+`).
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