Question

Which amino acid from following contains highest number of N atoms in it?

Options

• Histidine

• Lysine

• Arginine

• Glutamine

Answer 1

Arginine

Explanation:

Among the given amino acids, arginine contains a guanidine group in its side chain, which has three nitrogen atoms. Total nitrogen atoms in arginine = 4 (1 in the amino group + 3 in the side chain). This is higher than histidine (3 N), lysine (2 N), and glutamine (2 N).