How do Antibiotics work?

Antibiotics work by affecting things that bacterial cells have but human cells don't. For example, human cells do not have cell walls, while many types of bacteria do. The antibiotic penicillin works by keeping a bacterium from building a cell wall.

Antibiotics either stop bacteria from reproducing or destroy them. Before bacteria can multiply and cause symptoms, the body'simmune system can usually kill them. Our white blood cells attack harmful bacteria and, even if symptoms do occur, our immune system can usually cope and fight off the infection. Antibodies don't work on viruses, Viruses insert their genetic material into a human cell's DNA in order to reproduce. Antibiotics cannot kill viruses because bacteria and viruses have different mechanisms and machinery to survive and replicate. The antibiotic has no “target” to attack in a virus.