Question

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Rifampicin is used to treat various bacterial infections particularly tuberculosis. Reason (R): It acts by disrupting the bacterial cell-wall, nuclear membrane and mitochondria. In the light of the above statements, choose the most appropriate answer from the options given below:

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A) \
• B. Both (A) and (R) are correct but (R) is not the correct explanation of (A) \
• C. (A) is correct but (R) is not correct \
• D. (A) is not correct but (R) is correct

Hint:

Rifampicin blocks RNA Polymerase, stopping transcription. Remember the "R" connection: Rifampicin $\rightarrow$ RNA Polymerase inhibition.

Answer 1

The Correct Option is C

Step 1: Concept Antibiotics are highly targeted molecules designed to selectively inhibit specific bacterial pathways, such as transcription, translation, or replication, without disrupting host cell components.

Step 2: Meaning Disrupting membranes describes a broad, non-specific mechanism of action, whereas rifampicin relies on highly targeted enzyme inhibition.

Step 3: Analysis * Assertion (A) is correct: Rifampicin is a core first-line antibiotic used in combination therapies to treat infections caused by Mycobacterium tuberculosis. * Reason (R) is incorrect: Rifampicin does not destroy cell walls or membranes. Instead, it works by binding to and inhibiting the bacterial $\beta$-subunit of DNA-dependent RNA polymerase, blocking the synthesis of bacterial mRNA. Furthermore, bacteria lack nuclear membranes and mitochondria entirely.

Step 4: Conclusion Since the assertion is clinically correct but the reason contains false biological and mechanistic statements, option C is correct. Final Answer: (C)