Skip to main content
Back

Disruptors of Cell Membranes quiz

Control buttons has been changed to "navigation" mode.
1/15
  • What is the main mechanism by which lipopeptide antibiotics disrupt bacterial cell membranes?
    Lipopeptide antibiotics bind to lipopolysaccharides and insert their hydrophobic tails into the membrane, causing leakage.
  • Why are lipopeptide antibiotics selectively toxic to bacteria?
    They target unique bacterial membrane components, such as lipopolysaccharides, which are absent in human cells.
  • Which bacterial group are polymyxin antibiotics most effective against?
    Polymyxin antibiotics are most effective against gram-negative bacteria.
  • Why are polymyxin antibiotics ineffective against gram-positive bacteria?
    Gram-positive bacteria lack lipopolysaccharides, which are required for polymyxin binding and action.
  • What is the common use of polymyxin B?
    Polymyxin B is used as a topical antibiotic for skin infections and is found in over-the-counter ointments like Neosporin.
  • How does polymyxin B achieve its antibacterial effect?
    It binds to lipopolysaccharides in gram-negative bacteria and disrupts their cell membranes, causing leakage.
  • What is another name for polymyxin E?
    Polymyxin E is also known as colistin.
  • When is colistin (polymyxin E) typically used?
    Colistin is used as a last-resort drug for multidrug-resistant gram-negative infections.
  • What major risk is associated with colistin use?
    Colistin carries a risk of nephrotoxicity, requiring careful monitoring during treatment.
  • Why is colistin reserved for extraordinary cases?
    To prevent resistance and because of its narrow therapeutic window due to nephrotoxicity.
  • What mnemonic can help differentiate polymyxin B from polymyxin E?
    B is for basic use (over-the-counter), and E is for extraordinary use (last-resort drug).
  • What structural feature of gram-negative bacteria is targeted by lipopeptide antibiotics?
    Lipopeptide antibiotics target the lipopolysaccharides present in the outer membrane of gram-negative bacteria.
  • How do lipopeptides cause cell membrane disruption?
    They insert their hydrophobic tails into the membrane, making it leaky and compromising cell integrity.
  • What is the therapeutic window of colistin, and why is it important?
    Colistin has a narrow therapeutic window, meaning its safe dosage range is limited and must be carefully monitored.
  • Why is it important to limit the use of colistin?
    Limiting colistin use helps prevent the development of resistance and reduces the risk of nephrotoxicity.