Bio 150 Exam 2 Study Guide Questions With Complete Solutions

What is meant by selective toxicity? Correct Answer-Chemotherapeutic agents should act against the pathogen and not the host. Why are chemotherapeutic agents that work on the peptidoglycan cell wall of bacteria a good choice of drug? Correct Answer-Humans and other animal hosts lack peptidoglycan cell walls. Why is polymyxin only used on the skin? Correct Answer-It can also damage living human cell membranes, but the drug is safely used on the skin, where the outer layers of cells are dead. Quinolones and fluoroquinolones act against what bacterial target? Correct Answer-DNA gyrase Why is it difficult to find good chemotherapeutic agents against viruses? Correct Answer-Viruses depend on the host cell's machinery, so it is hard to find a viral target that would leave the host cell unaffected. Which antibiotic is overcome by beta-lactamases? Correct Answer-Penicillin How might efflux pumps increase antibiotic