Question

Which of the following compounds is an amino acid ?

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

The compound in which both amino $(-N{H}_2)$ as well as carboxylic acid ($-COOH$) groups are present is called an amino acid.
If $(-N{H}_2)$ group is present at same $C$(called $\alpha$ position) where ($-COOH$) is attached, it is called $\alpha$- amino acid. Similarly, if $(-N{H}_2)$ group is present on adjacent $C$ with respect to the $C$ directly attached with $-COOH$ (called $\beta$-position), it is $\beta$-amino acid and so on.
The given molecule is an example of $\alpha$-amino acid and is called alanine.
Hence, (b) is correct.