Which of the following statements is not correct?

Options

A. Proteins are polyamides formed from amino acids
B. Except glycine, all other amino acids show optical activity.
C. Natural protein are commonly made up of L-isomer of amino acids.
D. In a -amino acids, `-NH_2` and `-COOH` groups are attached to different carbon atoms.

Answer

D

Explanation

In `alpha`-amino acids, `-NH_2` and `-COOH` groups are attached to the same carbon atom,