Which amino acid among the following is optically inactive?

Solution

1. An amino acid is optically active if it possesses at least one chiral carbon atom.
2. The general structure of an amino acid is ${\text{R-CH(NH}}_2\text{)COOH}$.
3. In $\text{Glycine}$, the side chain $\text{R}$ is a hydrogen atom, $\text{H}$.
4. The structure becomes ${\text{H}}_2{\text{N-CH}}_2\text{COOH}$, which has no chiral center.
5. Hence the answer is (B).