Identify the structure of alanine when pH is 11 .

Alanine is an amino acid with an acidic carboxyl group and a basic amino group.

In a highly basic medium at pH $11$, the solution provides a large concentration of $\text{OH}^-$ ions.

Both the carboxyl group and the protonated amino group will lose their protons.

The $-\text{COOH}$ group deprotonates to form $-\text{COO}^-$, and the $-\text{NH}_3^+$ group deprotonates to form $-\text{NH}_2$.

Thus, alanine exists as an anion with the structure $\text{NH}_2\text{-CH(CH}_3\text{)-COO}^-$.

Answer: $\text{NH}_2\text{-CH(CH}_3\text{)-COO}^-$