
$\mathop {\begin{array}{*{20}{c}}
{\begin{array}{*{20}{c}}
{COOH\,\,} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{H - C - OH\,\,\,\,\,\,\,\,\,\,\,} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}
\end{array}} \\
{Br - C - H\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{\,\,\,COOC{H_3}}
\end{array}}\limits_{(I)} $ $\mathop {\begin{array}{*{20}{c}}
{\begin{array}{*{20}{c}}
{\,\,\,\,\,\,\,\,COOC{H_3}\,\,} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{H - C - Br\,\,\,\,\,\,\,\,\,\,\,} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}
\end{array}} \\
{HO - C - H\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{\,\,\,\,\,\,\,COOH\,\,\,\,\,\,\,\,}
\end{array}}\limits_{(II)} $
| List $I$ (Natural amino acid) | List $II$ (Code) |
| $A$ Glutamic acid | $I$ $Q$ |
| $B$ Glutamine | $II$ $W$ |
| $C$ Tyrosine | $III$ $E$ |
| $D$ Tryptophan | $IV$ $Y$ |