For what reason is penicillin lethal to bacteria yet essentially non-toxic for mammalian cells?
a. High population density of host cells neutralize its
effect
b. Mammalian cells are impermeable to penicillin
c. Mammalian cells inactivate penicillin
d. Penicillin does not affect cells with long generation
time
e. Target site is unique to bacteria.
The correct answer is e. Target site is unique to bacteria.
Penicillin is lethal to bacteria because it inhibits the synthesis of bacterial cell walls, specifically targeting the enzyme transpeptidase involved in the formation of peptidoglycan, a key component of bacterial cell walls. Mammalian cells lack cell walls and therefore are not affected by penicillin, making it essentially non-toxic to them.