Match the LIST-I with LIST-II.
| LIST-I (Side chain functional group) | LIST-II (Amino acid) |
| A. Isobutyl | I. Asparagine |
| B. 1° amine | II. Leucine |
| C. Amide | III. Tyrosine |
| D. Phenol | IV. Lysine |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A – II, B – IV, C – I, D – III
All α-amino acids have the general structure \( \ce{H2N-CH(R)-COOH} \). They differ only in the side chain R, and the side chain decides whether an amino acid is neutral, acidic or basic.
A. Isobutyl — This matches II. Leucine. Leucine has R = –\( \ce{CH2CH(CH3)2} \), an isobutyl group, so it is a neutral amino acid with a non-polar side chain.
B. 1° amine — This matches IV. Lysine. Lysine has R = –\( \ce{(CH2)4NH2} \), ending in a primary amino group, which makes it a basic amino acid.
C. Amide — This matches I. Asparagine. Asparagine has R = –\( \ce{CH2CONH2} \), an amide group; it is the amide of aspartic acid.
D. Phenol — This matches III. Tyrosine. Tyrosine has R = –\( \ce{CH2C6H4OH} \), a phenolic (4-hydroxyphenyl) group.
Shortcut: The pair B–IV appears only in Option (2).
NCERT (2026-27 edition):
Amino Acids – …
