The test used for identifying peptide linkage in proteins is

Name two $\alpha$-amino acids which form a dipeptide which is $100$ times more sweet than cane sugar?

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

Identify the basic $\alpha$-amino acid from the following.

The functional group which is found in amino acid is

Which of the following amino acids contains an alcohol functional group?