Question

Match the components of List I with those in the List II.
List I: A. Val, Leu; B. Ser, Thr; C. Arg, Lys; D. His, Trp
List II: I. Basic, II. Hydrophobic, III. Heterocyclic side chain, IV. Hydroxyl group in the side chain

• A. A-I, B-II, C-III, D-IV
• B. A-II, B-IV, C-I, D-III
• C. A-II, B-III, C-I, D-IV
• D. A-I, B-III, C-II, D-IV

Hint:

Ser/Thr = -OH (Hydroxyl). Val/Leu = C-H (Hydrophobic). Arg/Lys = + Charge (Basic).

Answer 1

The Correct Option is B

Step 1: Analysis of A
Valine (Val) and Leucine (Leu) have non-polar aliphatic side chains, making them hydrophobic (A-II).

Step 2: Analysis of B
Serine (Ser) and Threonine (Thr) contain a hydroxyl (-OH) group in their side chains (B-IV).

Step 3: Analysis of C
Arginine (Arg) and Lysine (Lys) are positively charged, basic amino acids (C-I).

Step 4: Conclusion
Histidine and Tryptophan contain heterocyclic rings (imidazole and indole, respectively) (D-III). The correct match is A-II, B-IV, C-I, D-III. Final Answer: (B)