Which of the following is not true about the denaturation of protein?

The proteins which are insoluble in water are

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?

Choose the correct option for structures of $A$ and $B,$ respectively.

Proteins are polymers of $\alpha$-amino acids,which are linked by peptide bonds. Chemically,proteins are:

Amino acids can be classified as $\alpha$,$\beta$,$\gamma$,$\delta$ and so on,depending upon the relative positions of the amino group with respect to the carboxyl group. Which type of amino acids form polypeptide chains in proteins?