Antibiotics is one of those technical terms in biology which actually describes its object. ANTI = against, BIOTIC = life. So antibiotics are weapons of mass destruction… sort of.
They are substances which occur both naturally, as well as artificially as made by humans. The reason they are so widespread and important is because they solve a problem humanity has had for a very long time (i.e. forever). They are used to treat bacterial infections. Today that might seem like a small thing, yet around the globe millions of people still die all the time due to bacterial infections (e.g. pneumonia). It’s not a small thing, it is one of the greatest medical discoveries.
A one-week course of antibiotics taken orally, for example, can easily treat bacterial infections and the associated disease. This is an amazing achievement. Antibiotics are substances which kill prokaryotic cells, such as bacteria, while leaving eukaryotic cells (in humans and others) untouched.
Each type of antibiotic targets different things in bacteria. One of the main differences between bacteria and human cells is that the former have a cell wall, while the latter don’t. Some antibiotics prevent the formation of cell walls. This renders the bacteria vulnerable to water flooding inside and bursting them. Burst bacteria can’t replicate (really?), and hence the infection ceases. This is called osmotic lysis. Lysis means breaking or disintegration, while osmotic refers to the osmotic effect which results in water…