Using drugs to treat diseases

-Often medicine you take has no effect on the pathogen it just eases the symptoms and makes you feel better 

-You have to wait for you immune system to overcome the invading microorganisms 

-Antibiotics:

-We use antiseptics and disinfectants to kill bacteria outside the body, but they are far to poisionus to use inside us 

- Antibiotics-> medicines which can kill disease causing bacteria inside your body 

-Alexander Fleming was a scientist who studied bacteria 

-In 1928, he was growing lots of bacteria on agar plates

-One day he went on holiday and left is lab untidy

-When he came back, he noticed that lots of his culture plates had mould growing on them

-He noticed a clear ring in the jelly around some of the spots of mould. Something had killed the bacteria covering the jelly 

-He extracted the juice and named it penicillin. But he couldm't get much of it from the mould

-After 10 years after penicillin was discovered, Ernst Chain and Howard Florey set about trying to use it on people 

-Eventually they managed to make penicillin on a industrial level, and was able to produce enough penicillin to supply the demands of the Second World War. 

-Antibiotics work by killing the bacteria which cause disease while they are inside your body 

-They damage bacterial cells without harming your own cells 

-However, antibiotics have no effect on diseases caused by viruses

-The problem with viral pathogens is that they reproduce inside the cells of your body. It is extremely difficult to develop drugs which kill the virus without damaging cells and tissues of your body at the same time