Question

(a) Who discovered Penicillin and how? Explain.

(b) Why is this discovery considered accidental?

(c) In what way did it prove to be a "milestone" in the field of medicine?

Hint:

Think of Fleming, the Staphylococcus plate contaminated by Penicillium, and the first antibiotic.

Answer 1

Step 1: Part (a): The discoverer and the method:
Penicillin was discovered by Alexander Fleming, a Scottish scientist, in 1928 at St Mary's Hospital, London.
He was growing Staphylococcus bacteria in culture plates in his laboratory.
He noticed that one plate was contaminated by a mould, Penicillium notatum.
Around the mould there was a clear zone where the bacteria had not grown.
Fleming concluded that the mould released a chemical that kills or stops the growth of bacteria. He named it penicillin.

Step 2: Part (b): Why the discovery was accidental:
Fleming was not looking for an antibiotic.
The mould spores entered the open plate by chance while he was away from the laboratory.
He did not plan the contamination. He only noticed the unexpected clear zone and had the insight to study it.
So the discovery came from chance observation, not from a planned experiment.

Step 3: Part (c): Why it was a milestone:
Penicillin was the first true antibiotic, a chemical made by a microbe that kills other microbes.
Later, Ernst Chain and Howard Florey purified it and tested it on animals and patients. They made it in large amounts.
It was used to treat wounded soldiers in the Second World War and saved many lives.
It opened the way to find many other antibiotics and made bacterial infections such as pneumonia and syphilis curable.
Fleming, Chain and Florey shared the Nobel Prize in 1945.

Final Answer:
(a) Alexander Fleming found Penicillin in 1928 from the zone of inhibition around Penicillium notatum on a Staphylococcus plate. (b) The contamination happened by chance. (c) It was the first antibiotic and began the antibiotic era.