Question

Which of the following represents the basic amino acids?

• A. A
• B. B
• C. C
• D. D

Answer 1

The correct option is D D

Amino acids are amphoteric compounds having a carboxylic group, amino group, hydrogen and a substituent group bonded to same carbon atom called the $\alpha$-carbon atom. The substituent group may be having one or more carboxylic groups or amino groups.

In case, the substituent group is having an extra amino group, the amino acid will be having more than one amino groups and will be positively charged at neutral pH and will be a basic amino acid like lysine and arginine.

Similarly if substituent group carries extra carboxylic group, the amino acid will carry negative charge at neutral pH and will be an acidic amino acid like aspartic acid and glutamic acid.

In case, the substituent group does not carry extra carboxylic or amino groups the amino acid is neutral amino acid example glycine, alanine, valine.