Fighting Disease - Drugs

Question 1

What are painkillers and what do they do?

Answer 1

Painkillers (e.g aspirin) are drugs that relieve pain. They don’t actually tackle the cause of the disease or kill pathogens, they just help to reduce the symptoms.

Question 2

Give an example of other drugs that reduce the symptoms without tackling the underlying cause?

Answer 2

“Cold remedies” don’t actually cure colds.

Question 3

What do antibiotics do?

Answer 3

1. Antibiotics (e.g. penicillin) actually kill (or prevent the growth of) the bacteria causing the problem without killing your own body cells. Different antibiotics kill different types of bacteria, so it’s important to be treated with the right one. 2. Antibiotics don’t destroy viruses (e.g. flue or cold viruses). Viruses reproduce using your body cells, which makes it very difficult to develop drugs that destroy just the virus without killing the body’s cells.

Question 4

What has the use of antibiotics done to the number of deaths from communicable diseases caused by bacteria?

Answer 4

Greatly reduced the number of deaths.

Question 5

Explain the facts behind bacteria becoming resistant to antibiotics.

Answer 5

1. Bacteria can mutate - sometimes the mutations cause them to be resistant to an antibiotic.
2. If you have an infection, some of the bacteria might be resistant to antibiotics. This means that when you treat the infection, only the non-resistant strains of bacteria will be killed. The individual resistant bacteria will survive and reproduce, and the population of the resistant strain will increase (example of natural selection). This resistant strain could cause a serious infection that can’t be treated by antibiotics. E.g. MRSA causes serious wound infections and is resistant to the powerful antibiotic meticillin.
   To slow down the rate of development of resistant strains, it’s important for doctors to avoid over-prescribing antibiotics. So you won’t get them for a sore throat, only for something more serious. Also important you finish the whole course of antibiotics and don’t stop once you feel better.

Question 6

Why do plants produce chemicals?

Answer 6

To defend themselves against pests and pathogens.

Question 7

Some chemicals produced by plants can be used as drugs to do what?

Answer 7

Treat human diseases or relieve symptoms.

Question 8

Give two examples of medicine that were discovered by studying plants used in traditional cures.

Answer 8

1. Aspirin is used as a painkiller and to lower fever. It was developed from a chemical found in willow.
2. Digitalis is used to treat heart conditions. It was developed from a chemical found in foxgloves.

Question 9

Name a drug that was discovered by being extracted from microorganisms.

Answer 9

Alexander Fleming was clearing out some Petri dishes containing bacteria. He noticed that one of the dishes of bacteria also had mould on it and the area around the mould was gree of the bacteria.
He found the mould (called Penicillium notatum) on the Petri dish was producing a substance that killed the bacteria - penicillin.

Question 10

How are drugs made now?

Answer 10

On a large scale in the pharmaceutical industry - they’re synthesised by chemists in labs. However, the process might still start with a chemical extracted from a plant.