Discovery of Penicillin. Most of us have heard of Penicillin, penicillin the wonder working drug that cures many bacteria diseases.
Discovery of Penicillin
This penicillin was accidentally discovered by Sir, Alexander fleming, while he was studying the growth of a certain type of bacterium. His immediate gasp of the significance of the observed phenomenon and his systematic approach to investigating it are typical of the way scientist work.
Scientist make research and when something is been discovered, they put fort a hypothesis, if the hypothesis is positive they put fort a theory, but if it turns out to be negative they take the experiment again. so,
fleming was studying the growth and reproduction of bacterium staphylococcus, in dishes containing agar to which nutrients had been added.
He observed that a mould(penicillin) was also growing in some of the dishes. the mould had got into the dish by accident, in addition, he observed a clear zone around the area where the mould grew, indicating that the bacteria growing there had died.
what had caused the bacteria to die?
Fleming put forward a hypothesis: The mould produced a chemical which diffused into the surrounding agar a killed the bacteria.
To test this hypothesis, he designed an experiment. he grew the mould in a liquid nutrient broth so that the chemical it produced would diffuse into the broth. he added some of this broth minus the mould to the bacteria, he observed that the bacteria died after the broth was added. was there something in the nutrients broth that caused the bacteria to die? to find out the answer to this question, he added some nutrients broth in which no mould had been grown to the bacteria. the bacteria did not die.
This confirmed that fleming hypothesis was correct. it was tested by other scientists and was confirmed to be true. the chemical was isolated and named penicillin.