Q.23 Match List I with List II
| List I (Chemical nature of side chain) | List II (Amino Acid) |
|---|---|
| A. Aliphatic amino acid B. Sulphur containing C. Imino D. Amide |
I. Pro II. Gln III. Val IV. Cys |
Choose the correct answer from the options given below:
Amino acids are classified by their side chain (R-group) chemical nature, and this matching question tests standard biochemistry knowledge. The correct answer is option (D): (A) – (III), (B) – (IV), (C) – (I), (D) – (II).
Correct Matching
Valine matches aliphatic (nonpolar hydrocarbon chain like -CH(CH₃)₂), cysteine matches sulphur-containing (-CH₂SH), proline matches imino (cyclic secondary amine, not primary NH₂), and glutamine matches amide (-CH₂CH₂CONH₂).
| List I | List II | Amino Acid | Side Chain Example |
|---|---|---|---|
| A. Aliphatic amino acid | III | Val | -CH(CH₃)₂ (hydrocarbon) |
| B. Sulphur containing | IV | Cys | -CH₂SH |
| C. Imino | I | Pro | Cyclic pyrrolidine ring |
| D. Amide | II | Gln | -CH₂CH₂CONH₂ |
Option Explanations
Option (A) mismatches all: Proline is imino, not aliphatic; Gln is amide, not sulphur; Val is aliphatic, not imino; Cys is sulphur, not amide.
Option (B) errs on A-Pro (imino), B-Val (aliphatic, no sulphur), C-Gln (amide), keeps D-Cys correct.
Option (C) fails on A-Pro (imino), B-Gln (amide, no sulphur), C-Cys (sulphur), D-Val (aliphatic).
Option (D) is correct as detailed above.
This SEO-friendly guide breaks down the exact matches for biochemistry students preparing for exams like NEET or CSIR NET, focusing on chemical nature classifications.
