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Treating, curing and preventing disease - Edexcel Antibiotics

The immune system defends humans from pathogens. Physical and chemical barriers prevent infection. White blood cells attack pathogens. Immunisations usually involve injecting inactive pathogens.

Part of Biology (Single Science)Health, disease and the development of medicines

Antibiotics

are substances that slow down or stop the growth of . They are commonly prescribed medicines, examples include penicillin and amoxicillin. These can be taken to cure the by killing the , but only cure bacterial diseases and not viral ones.

A microscope image of penicillin damaging a bacterial cell
Image caption,
A bacterial cell damaged by penicillin

Penicillin

Penicillin was the first antibiotic discovered in 1928 by Alexander Fleming. He noticed that some bacteria he had left in a had been killed by the naturally occurring Penicillium .

How do antibiotics work?

Antibiotics damage the bacterial cells by inhibiting their cellular processes, but do not damage the host cells. They have the ability to cure some bacterial diseases that would have previously killed many people. Since their introduction, they have had a large influence on the world's health and death rate.

Different bacteria cause different diseases. One antibiotic may only work against one type of bacteria, or a few types. This means that a range of different antibiotics is needed for the treatment of the whole range of bacterial diseases.

Viral diseases

Viral diseases cannot be cured by antibiotics, as they reproduce inside the host cells. It is very difficult to develop antiviral drugs, as they might damage the host cell whist killing the virus. Antiviral drugs only slow down viral development, and viruses change their quickly which means new drugs have to be generated regularly.

Viral diseases cannot be cured by antibiotics, as they reproduce inside the host cells. It is very difficult to develop Antiviral drugs, as they might damage the host cell whist killing the virus.