Question

Zwitter ion.

Hint:

Zwitter ions are electrically neutral overall, but carry both +ve and –ve charges.

Answer 1

Step 1: Nature of amino acids.
Amino acids contain both an acidic group (–COOH) and a basic group (–NH\(_2\)). Step 2: Behaviour in water.
In aqueous solution, –COOH donates a proton forming –COO\(^{-}\), while –NH\(_2\) accepts a proton forming –NH\(_3^+\). Step 3: Dipolar form.
Thus, the molecule carries both positive and negative charges simultaneously, existing as a zwitterion. Step 4: Example.
For glycine: \[ H_2N-CH_2-COOH \ \longrightarrow \ ^+H_3N-CH_2-COO^- \] Step 5: Conclusion.
At isoelectric point, the amino acid exists mainly in zwitterionic form with no net charge.