Structures of alanine at pH = 2 and pH = 10 are respectively

MCQ

Structures of alanine at $pH = 2$ and $pH = 10$ are respectively

✓
$\begin{array}{*{20}{c}}
{C{H_3}\,\,\,\,\,}\\
{|\,\,\,\,\,\,\,\,}\\
{\mathop N\limits^ + {H_3} - CH - COOH}
\end{array}$ and $\begin{array}{*{20}{c}}
{C{H_3}\,\,\,}\\
{|\,\,\,\,\,\,\,}\\
{{H_2}N - CH - CO{O^ - }}
\end{array}$
B
$\begin{array}{*{20}{c}}
{C{H_3}\,\,\,}\\
{|\,\,\,\,\,\,\,}\\
{{H_2}N - CH - CO{O^ - }}
\end{array}$ and $\begin{array}{*{20}{c}}
{C{H_3}\,\,\,\,\,}\\
{|\,\,\,\,\,\,\,\,}\\
{\mathop N\limits^ + {H_3} - CH - COOH}
\end{array}$
C
$\begin{array}{*{20}{c}}
{C{H_3}\,\,\,}\\
{|\,\,\,\,\,\,\,}\\
{{H_2}N - CH - CO{O^ - }}
\end{array}$ both
D
$\begin{array}{*{20}{c}}
{C{H_3}\,\,\,\,\,}\\
{|\,\,\,\,\,\,\,\,}\\
{\mathop N\limits^ + {H_3} - CH - COOH}
\end{array}$ both

✓

Answer

Correct option: A.

$\begin{array}{*{20}{c}}
{C{H_3}\,\,\,\,\,}\\
{|\,\,\,\,\,\,\,\,}\\
{\mathop N\limits^ + {H_3} - CH - COOH}
\end{array}$ and $\begin{array}{*{20}{c}}
{C{H_3}\,\,\,}\\
{|\,\,\,\,\,\,\,}\\
{{H_2}N - CH - CO{O^ - }}
\end{array}$

a
Alanine zwitter ion is $\begin{array}{*{20}{c}}
{C{H_3}\,\,} \\
{|\,\,\,\,\,\,\,\,} \\
{{H_3}\mathop N\limits^ \oplus - CH - CO{O^\Theta }}
\end{array}$

$\begin{array}{*{20}{c}}
{{H_3}\mathop N\limits^ \oplus - CH - COOH} \\
{|\,\,\,\,\,\,\,\,\,\,} \\
{C{H_3}\,\,}
\end{array}$ $\underset{{O{H^\Theta }}}{\overset{{{H^ \oplus }}}{\longleftrightarrow}}$ $\begin{array}{*{20}{c}}
{{H_3}\mathop {\mathop N\limits^ \oplus - CH - CO{O^\Theta }}\limits^{} } \\
{|{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} } \\
{C{H_3}}
\end{array}$ $\underset{{^\Theta OH}}{\overset{{{H^ \oplus }}}{\longleftrightarrow}}$ $\begin{array}{*{20}{c}}
{{H_2}N - CH - CO{O^\Theta }} \\
{|\,\,\,\,\,\,\,\,} \\
{\,C{H_3}\,\,}
\end{array}$