What cellular components do some bacterial cells have that make them powerful pathogens? explain your answer. why are penicillins often more effective against gram-positive bacteria than gram-negative bacteria? why is it important to understand the structure of a bacterial cell when developing an antibiotic? how do antibiotics work without harming the surrounding human cells? what class of antibiotics would you prescribe for sue? explain your answer. why are antibiotics not effective against viruses? (think back to what you learned about viruses in pbs.)