Question

If the basic formula of an α-amino acid is $R-CH\left(N{H}_2\right)-COOH$, where R is the side chain, what is the primary point of distinction between any two proteins?

• A. Number of amino groups
• B. Number of carboxyl groups
• C. The side chain R
• D. Relative positions of amino, carboxyl groups and R

Answer 1

The correct option is C The side chain R

$\alpha$-amino acids are the constituents of proteins. Different proteins are formed by polymerisation of different $\alpha$-amino acids, which are formed due to the difference in the side chain substituted group R, which may be as simple as hydrogen or as complex as imidazole.