Over 100 years ago, microbiologist paul ehrlich talked about his concept of the ideal antibiotic as a "magic bullet" that could kill harmful bacteria but have minimal side effects for the infected person. how do antibiotics accomplish this goal?

Antibiotics accomplish this goal killing the bacteria, or by keeping them from replicating. Bacteria cells have what human cells don't; cell walls. Antibiotics keeps the bacteria from building those walls.

Explanation:

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.