EVERYDAY SCIENCE

Detailed explanation-1: -What is an antibiotic? Antibiotics are medicines that fight infections caused by bacteria in humans and animals by either killing the bacteria or making it difficult for the bacteria to grow and multiply.

Detailed explanation-2: -In order to be useful in treating human infections, antibiotics must selectively target bacteria for eradication and not the cells of its human host.

Detailed explanation-3: -Antibiotics are able to selectively target specific types of bacteria without harming the infected host.

Detailed explanation-4: -Antibiotics Seek Out Bacterial Cells 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.

Detailed explanation-5: -Selective effects occur in selective compartments, where particular antibiotic concentrations result in a differential growth rate of resistant bacterial variants. This may happen even at very low antibiotic concentrations able to select low-level-resistant bacteria.