This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Microbiology Pa-2 and Pa-3 (Sterilization and Bacterial Genetics), Subject name: Microbiology
[{'content': 'Which of the following sterilization/disinfection agents works by disrupting the cell membrane? \nSelect and explain. \nA. Phenols, B. Halogenated compounds, C. Heavy metals, D. Ethylene oxide', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Option 1 They are bactericidal or bacteriostatic and some are fungicidal also. They act by denaturing proteins and disrupting cell membranes. Option 2 Mode of action of Halogens: All preparations yield hypochlorous acid (HClO) which causes oxidative destruction of vegetative bacteria and fungi, but not spores. Option 3 Mode of action of Heavy metals: Heavy metals combine with bacterial cell proteins, often with their sulphydryl groups, and inactivate them. They may also precipitate cell proteins. Option 4 Ethylene oxide sterilizer is one of the widely used gaseous chemical sterilants in present days. It has high penetration power, has both microbicidal and sporicidal activity; acts by combining with cell proteins.', 'role': 'assistant'}]