Fighting disease - Drugs

Question 1

What are painkillers (aspirin) and what do they do and not do ? Example

Answer 1

Drugs which relieve pain .

Don’t tackle the cause of disease or kill pathogens but they do help to reduce the symptoms .

Example: Lots of cold remedies don’t actually cure colds

Question 2

What are antibiotics (penicillin) and what do they do and not do ?
Effect of anti biotics

Answer 2

do = kill the bacteria causing the problem without killing your own body cells. Diff antibiotics kill diff types of bacteria so it’s important to be treated with the right antibiotic.

Don’t = destroy viruses, viruses reproduce using body cells which makes it difficult to develop drugs that destroy just the virus w/o killing the body cells.

The use of antibiotics had greatly reduced the number of deaths by communicable diseases by bacteria.

Question 3

What can bacteria do and what are the causes of this ?

Answer 3

mutate, this can cause them to become resistant to an antibiotic.
If you have an infection some bacteria might become resistant to antibiotics .

Question 4

Example of natural selection

Answer 4

Individual resistant cells survive and reproduce and population of resistant cells will increase.

This resistant strain could cause a serious infection that can’t be treated by antibiotics. E.g. MRSA causes serious wound infection and is resistant to powerful antibiotic meticillin

To slow down the rate of development of resistant strains its important for doctors to avoid over prescribing anti biotics. And important you finish your whole course of antibiotics even when you feel better.

Question 5

Plants produce a variety of chemicals to defend themselves against pests and pathogens. Some of these chemicals can be used as drugs to treat human diseases or relive symptoms . Some of our current medicines discovered by studying plants used in traditional cures. For example:

Answer 5

Aspirin used as painkiller and to lower fever - developed from chemical found in willow.

Digitalis used to treat heart conditions and developed from chemical found in foxgloves

Question 6

Some drugs were extracted from microorganisms
For example:

Answer 6

Fleming was clearing out petri dishes containing bacteria, he notices one of the dishes of bacteria had mould on it and the area around the mould was free of bacteria. He found that the mould ( penicillium notatum ) on the petri dish was producing a substance that killed bacteria - this substance = penicillin

These days drugs are made in large pharmaceutical industry - they’re synthesised by chemists in labs. However this process might still start with a chemical extracted from plant.