Question

Which of the following is not true about amino acids?

• A. They are constituents of all proteins
• B. Alanine having one amino and one carboxylic group
• C. Most naturally occurring amino acids have D-configuration
• D. Glycine is the only naturally occuring amino acid which is optically inactive.

Answer 1

The correct option is C Most naturally occurring amino acids have D-configuration

Glycine, the first member of $\alpha$ amino acids, is optically inactive.
Most naturally occuring amino acids have L-configuration.
$\alpha$-amino acids are the constituents of proteins. Different proteins are formed by polymerisation of different $\alpha$-amino acids.
Hence option (c) is correct.