Question

Which amino acid is most basic?

• A. Proline
• B. Serine
• C. Lysine
• D. Alanine

Answer 1

The correct option is C

Lysine

Amino acids are classified as acidic or basic amino acids due to the presence of carboxyl and amino groups.

If the number of carboxyl groups are more then it is called as acidic amino acid and if the number of amino groups are more then it is a basic amino acid.

The explanation for the correct answer

(C) Lysine

1. Amino acids contain amino(${\mathrm{NH}}_2$) and carboxyl($\mathrm{COOH}$) functional group.
2. These are classified on the basis of acidic, basic and neutral amino acids.
3. The basic amino acids contain more number of amino groups and acidic contain more carboxyl groups.
4. Lysine, Arginine, and Histidine are the basic amino acids.
5. Hence, option C is the most basic amino acid.

The explanation for the incorrect answer

(A) Proline

1. Proline is an example of non-polar, cyclic amino acids.
2. It is not a basic amino acid.
3. Thus, this option is incorrect.

(B) Serine

1. It is a polar amino acid.
2. It is not a basic amino acid.
3. Thus, this is an incorrect option.

(D) Alanine

1. It is a non-polar amino acid.
2. It is not a basic amino acid.
3. Thus, it is an incorrect answer.

Therefore, the correct option is C.