Q.65 As an antiseptic, alcohol is effective against
(A) bacteria and non-enveloped viruses
(B) bacterial endospores and fungi
(C) bacteria and fungi
(D) fungi and non-enveloped viruses
Alcohol serves as a widely used antiseptic effective primarily against certain microorganisms by denaturing proteins and disrupting lipid membranes. The correct answer to the question “As an antiseptic, alcohol is effective against” is (C) bacteria and fungi.
Correct Answer Explanation
Alcohol, such as ethanol or isopropanol at 60-90% concentrations, rapidly kills vegetative bacteria by damaging their cell walls and proteins. It also targets fungi effectively through similar mechanisms, making option (C) the most accurate choice for standard antiseptic use.
Option Analysis
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(A) Bacteria and non-enveloped viruses: Alcohol works well against bacteria but fails against non-enveloped viruses like norovirus, which lack lipid envelopes vulnerable to disruption.
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(B) Bacterial endospores and fungi: While effective against fungi, alcohol cannot penetrate or destroy resistant bacterial endospores, such as those from Clostridium.
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(C) Bacteria and fungi: This matches alcohol’s proven spectrum, inactivating vegetative bacteria and most fungal cells without spore resistance issues.
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(D) Fungi and non-enveloped viruses: Alcohol handles fungi but remains ineffective against non-enveloped viruses due to their stable protein capsids.
