Question

Match LIST-I with LIST-II

Choose the correct answer from the options given below:

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

Hint:

Categorize antibiotics by target: Cell Wall (\(\beta\)-lactams like Cephalosporins), DNA Synthesis (Quinolones like Nalidixic acid), Protein Synthesis (Macrolides like Erythromycin target 50S), and Metabolic Pathways (Isoniazid targets mycolic acid synthesis).

Answer 1

The Correct Option is C

Step 1: Concept Explanation:
The question involves matching antimicrobial agents with their mechanisms of action.
Step 2: Detailed Solution:
Matching each agent from LIST-I with its mechanism from LIST-II:


A. Cephalosporins: As \(\beta\)-lactam antibiotics, cephalosporins inhibit transpeptidases, which are essential for peptidoglycan synthesis. Therefore, A matches I. Act by inhibition of biosynthesis of the peptidoglycan cell-wall structure.

B. Nalidixic acid: As a quinolone antibiotic, nalidixic acid inhibits DNA gyrase, crucial for DNA replication, repair, and recombination. Therefore, B matches II. Inhibition of DNA synthesis in gram-negative bacteria.

C. Isoniazid: This drug inhibits mycolic acid synthesis, a key component of the Mycobacterium cell wall, by blocking pyridoxal phosphate and NAD-catalyzed reactions. Therefore, C matches IV. Blocking pyridoxin and nicotinamide - catalyzed reactions in the microbial cell.

D. Erythromycin: As a macrolide antibiotic, erythromycin binds to the 50S ribosomal subunit, inhibiting protein synthesis. Therefore, D matches III. Inhibits protein synthesis as a result of binding on the 50S subunit ribosome.

Step 3: Final Answer:
The correct matches are A-I, B-II, C-IV, and D-III, corresponding to option (C).