Q.76 Match compounds in Group I with inhibitory activities in Group II.
| Group I |
|---|
| (P) Vancomycin (Q) Rifampin (R) Puromycin (S) Ciprofloxacin |
| Group II |
|---|
| (i) Folate metabolism (ii) DNA synthesis (iii) Protein synthesis (iv) RNA synthesis (v) Cell wall synthesis |
(A) P-v, Q-iv, R-iii, S-ii
(B) P-iv, Q-iii, R-i, S-ii
(C) P-iv, Q-i, R-iii, S-ii
(D) P-v, Q-iii, R-ii, S-iv
Introduction
Antibiotics act by targeting specific and essential cellular processes in microorganisms, such as cell wall synthesis, DNA replication, RNA transcription, and protein synthesis. Understanding the mechanism of action of antibiotics is a core topic in microbiology, biotechnology, and pharmacology, and is frequently tested in competitive exams.
In this article, we match compounds from Group I with their correct inhibitory activities from Group II, followed by a detailed explanation of all answer options.
Correct Matching and Explanation
P. Vancomycin → (v) Cell wall synthesis
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Vancomycin inhibits peptidoglycan synthesis by binding to D-Ala-D-Ala residues.
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It is mainly effective against Gram-positive bacteria.
Q. Rifampin → (iv) RNA synthesis
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Rifampin inhibits DNA-dependent RNA polymerase.
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This blocks transcription, preventing RNA synthesis.
R. Puromycin → (iii) Protein synthesis
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Puromycin mimics aminoacyl-tRNA.
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It causes premature termination of polypeptide chains during translation.
S. Ciprofloxacin → (ii) DNA synthesis
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Ciprofloxacin inhibits DNA gyrase and topoisomerase IV.
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This prevents DNA replication and transcription.
Correct Answer
✅ Option (A)
P-v, Q-iv, R-iii, S-ii
Option-Wise Analysis
Option (A)
✅ Correct
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All antibiotics are accurately matched with their true mechanisms of action.
Option (B)
❌ Incorrect
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Puromycin does not inhibit folate metabolism.
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Ciprofloxacin does not inhibit RNA synthesis.
Option (C)
❌ Incorrect
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Vancomycin does not inhibit RNA synthesis.
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Rifampin does not inhibit folate metabolism.
Option (D)
❌ Incorrect
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Rifampin does not inhibit protein synthesis.
-
Ciprofloxacin does not inhibit RNA synthesis directly.
Quick Revision Table
| Antibiotic | Primary Target |
|---|---|
| Vancomycin | Cell wall synthesis |
| Rifampin | RNA synthesis |
| Puromycin | Protein synthesis |
| Ciprofloxacin | DNA synthesis |
Conclusion
Antibiotics are highly specific in their action, and correct identification of their inhibitory targets is essential for both exam success and conceptual clarity.
Among all the given choices, Option (A) correctly matches each antibiotic with its inhibitory activity.
Final Answer
✅ Option (A): P-v, Q-iv, R-iii, S-ii
