What are antibotics? List the properties of antibiotics to be used as medicine.

Explanation

Antibiotics are the substances, primarily produced by certain useful micro-organisms which in low concentrations are antagonistic to the growth of harmful micro-organisms such as pathogenic bacteria. This property of antibiotics to kill the pathogenic micro-organisms is called antibiosis. Medicinally important antibiotics have quick and broad-spectrum therapeutic effects but with minimum side effects. Some medicinally important antibiotics are Penicillin (first discovered antibiotic by Alexander Flemming), aureomycin, erythromycin, neomycin, streptomycin, terramycin, chloromycetin, etc.
Every antibiotic is known to block some specific step of specific metabolic pathway and will be effective against all those microbes which have similar biochemical mechanisms. This is the reason that most antibiotics work against many species of bacteria which have similar metabolic pathways rather than working against one e.g. Penicillin is a broad-spectrum antibiotic and inhibits the growth of a number of bacterial pathogens as it blocks the metabolic processes that build the cell. wall in bacteria but is not much effective on human cells as these do not have cell wall. But the antibiotics used to treat the bacterial diseases may not be useful against the viral infections.