Micro & Immunology · single question
What is the mechanism by which a sanitizer (hand sanitizer/disinfectant) kills microorganisms?
Show answer and explanation
Correct answer: D. Denaturation of proteins
Alcohol-based sanitizers and most chemical disinfectants kill microorganisms primarily through protein denaturation — disrupting the three-dimensional structure of essential proteins (enzymes, structural proteins, membrane proteins), causing irreversible loss of function and cell death. This is a non-specific mechanism that is why resistance to alcohols rarely develops (unlike antibiotic resistance).
- A. ❌ DNA replication inhibition is the mechanism of fluoroquinolones and metronidazole — not sanitizers.
- B. ❌ Peptidoglycan synthesis inhibition is the mechanism of beta-lactam antibiotics (penicillin) — not sanitizers.
- C. ❌ Ribosomal inhibition is the mechanism of aminoglycosides, macrolides, tetracyclines — not sanitizers.
- D. ✅ CORRECT – Chemical sanitizers and alcohol disinfectants work primarily through protein denaturation, disrupting microbial cellular function.
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