Optically inactive amino acid is :-

Within the list shown below,the correct pair of structures of alanine in $pH$ ranges $2-4$ and $9-11$ is:
$I$. $H_{3}N^{+}CH(CH_{3})COOH$
$II$. $H_{2}NCH(CH_{3})COO^{-}$
$III$. $H_{3}N^{+}CH(CH_{3})COO^{-}$
$IV$. $H_{2}NCH(CH_{3})COOH$

For an amino acid,the ionization constant for the carboxyl group is $pK_{a_1} = 2.34$ and for the ammonium ion is $pK_{a_2} = 9.6$. At what $pH$ will the isoelectric point of the amino acid be?

In a linear tetrapeptide (constituted with different amino acids),the value of (number of amino acids) - (number of peptide bonds) is:

The general structural formula of $\alpha$-amino acid is $NH_2-CH(R)-COOH$. The group $R$ in tryptophan $(X)$ and histidine $(Y)$ are respectively:

In which of the following processes does protein $NOT$ participate?