Question 4 of 14

(demo test)

Product Demo for Part I Questions

What is the mechanism underlying the antibacterial activity of trimethoprim and the sulfonamides?

A. inhibition of ribosome function

B. inhibition of cell wall synthesis

C. inhibition of folate metabolism

D. inhibition of nucleic acid synthesis

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Category:

Systemic Health

Topic:

Pharmacology

High Yield:

No

Your Answer:

U

Correct Answer:

C

Explanation:

Trimethoprim and the sulfonamides (e.g. Bactrim) inhibit folate metabolism.  Folate is needed in DNA synthesis as seen in the flowchart below.

Macrolides, aminoglycosides, and tetracyclines inhibit the formation of ribosomes which is needed in RNA synthesis.

The ß-Lactams (e.g. penicillins) and glycopeptide (e.g. vancomycin) antibiotics inhibit cell wall synthesis.  

The polymyxins disrupt cytoplasmic membrane function while the quinolones and rifampicin inhibit nucleic acid synthesis.

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