Question

which of the following causes damage to the cell membrane? choose all that apply

polymyxin
tetracycline
penicillin
ciprofloxacin

Explanation:

• Polymyxin: It disrupts the cell membrane by interacting with lipopolysaccharides (in Gram - negative bacteria) and phospholipids, leading to membrane damage.
• Tetracycline: It mainly inhibits protein synthesis by binding to the 30S ribosomal subunit, not directly damaging the cell membrane.
• Penicillin: It inhibits the synthesis of the bacterial cell wall (by interfering with peptidoglycan synthesis), not the cell membrane.
• Ciprofloxacin: It acts by inhibiting DNA gyrase (topoisomerase II) and topoisomerase IV, which are involved in DNA replication and repair, not by damaging the cell membrane.

Answer:

polymyxin