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

The isoelectric point of alanine is $pH = 6$. At which $pH$ will the maximum concentration of the zwitterion of alanine be present?

The monomer of a polypeptide is........

Amino acids contain which of the following functional groups?

White precipitate is formed in

The general structure of $\alpha$-amino acid can be represented as shown below. Which amino acid is not correctly matched with the $R$ group given?