B$C{H_3} - \mathop {\mathop {CH{\text{ }} - {\text{ }}}\limits_{|{\kern 1pt} {\kern 1pt} \,\,\,\,\,\,\,\,\,\,\,\,\,{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} } }\limits_{N{H_2}{\kern 1pt} \,\,\,\,\,\,\,\,\,} \mathop {\mathop {{\text{ }}C}\limits^{\,\,||} }\limits^{\,\,\,O} - OH$
b
(b) $C{H_3} - \mathop {\mathop C\limits_| H}\limits_{N{H_2}} - COOH$
The compounds in which both amino $( - N{H_2})$as well as acidic $(-COOH)$ group is present is called amino acid.