Beginning of Essay
have played a major role in our society thanks to Sir Alexander Fleming’s careful observations in 1928. Without it, many lives would be in danger due to infectious diseases. are chemical substances produced by various species of microorganisms and other living ....

Middle of Essay
.... be bacteriostatic (bacteria stopped from multiplying) or bactericidal (bacteria killed). To perform either of these functions, antibiotics must be brought into contact with the bacteria. It is believed that antibiotics interfere with the surface of bacteria cells, causing a change in their ability to reproduce. Testing the action of an antibiotic in the laboratory shows how much exposure to the drug is necessary to halt reproduction or to kill the bacteria. Although a large amount of an antibiotic taken at one time might kill the bacteria causing an illness, such a dose usually would make the person suffer from illness caused by the drug. Therefore ....