Match List-I with List-II :
| List-I (Amino Acid) | List-II (Nature of Amino Acid) |
| (A) Valine | (I) Basic amino acid |
| (B) Glycine | (II) Neutral optically active amino acid |
| (C) Lysine | (III) Acidic amino acid |
| (D) Glutamic acid | (IV) Neutral optically inactive amino acid |
Choose the correct answer from the options given below :
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A) - (II), (B) - (IV), (C) - (I), (D) - (III)
An amino acid is neutral when it has one amino and one carboxyl group, basic when it has more amino than carboxyl groups, and acidic when it has more carboxyl than amino groups. It is optically active when its α-carbon is chiral (four different groups); only glycine, whose side chain is H, is optically inactive.
(A) Valine — This matches (II) Neutral optically active amino acid. Side chain –\( \ce{CH(CH3)2} \): one –\( \ce{NH2} \), one –COOH, chiral α-carbon.
(B) Glycine — This matches (IV) Neutral optically inactive amino acid. \( \ce{H2N-CH2-COOH} \): the α-carbon carries two H atoms, so it is not chiral.
(C) Lysine — This matches (I) Basic amino acid. Its side chain, –\( \ce{(CH2)4NH2} \), carries a second amino group.
(D) Glutamic acid — This matches (III) Acidic amino acid. Its side chain, –\( \ce{CH2CH2COOH} \), carries a second carboxyl group.
Shortcut: Glycine is the only optically inactive amino acid, so (B)–(IV); only Option (4) has this pair.
NCERT (2026-27 edition):
Classification of Amino Acids
NCERT (2026-27 edition):
Classification of Amino Acids – “… Except glycine, all other naturally occurring α-amino acids are optically active, since the α-carbon atom is asymmetric.”