B6 Preventing and treating disease

Question 1

Antigen

Answer 1

a protein on the surface of a substance (often a pathogen) that triggers an immune response

Question 2

How does a vaccine work?

Answer 2

Small amounts of a dead or inactive pathogen are put into your body, often by injection. The antigens in the vaccine stimulate the white blood cells into making antibodies. The antibodies destroy the antigens without any risk of you getting the disease. You are immune to future infections by the pathogen because your body can respond rapidly and make the correct antibody as if you had already had the disease.

Question 3

Herd immunity

Answer 3

the protection given to a population against an outbreak of a specific disease when a very high percentage of the population are immune (usually through vaccination)

Question 4

Aspirin originates from…

Answer 4

a compound found in the bark of willow trees

Question 5

Name two drugs extracted from foxglove

Answer 5

digitalis and digoxin (help strengthen the heartbeat)

Question 6

Who discovered penicillin?

Answer 6

Alexander Fleming

Question 7

Why are most new drugs synthesised by chemists?

Answer 7

compounds showing promise can be modified to produce more powerful molecules that can be synthesised easily and cheaply

Question 8

A good medicine should be…

Answer 8

effective, safe, stable, successfully taken into and removed from your body

Question 9

First stage of preclinical drug trials

Answer 9

drugs are tested using computer models and human cells and tissues (grown using human stem cells in the laboratory)

Question 10

Second stage of preclinical drug trials

Answer 10

drugs are tested on live animals to test efficacy, toxicity, and dosage

Question 11

First stage of clinical trials

Answer 11

very low doses are given to healthy people to check for side effects

Question 12

Second stage of clinical trials

Answer 12

the drug is tried on a small number of patients to check if it treats the disease

Question 13

Third stage of clinical trials

Answer 13

bigger clinical trials take place to find the optimum dose

Question 14

What are double blind trials?

Answer 14

when neither the doctor nor the patient knows whether the patient received a placebo

Question 15

B Lymphocytes

Answer 15

white blood cells that make antibodies but cannot divide

Question 16

Hybridoma cell

Answer 16

a hybrid cell formed when a lymphocyte is fused with a type of tumour cell

Question 17

How are monoclonal antibodies produced?

Answer 17

B lymphocytes are fused with tumour cells to create a hybridoma. The hybridoma divide to produce a large number of clone cells which are then harvested for antibodies

Question 18

How do monoclonal antibodies work in pregnancy tests?

Answer 18

Tiny amounts of the hormone HCG (produced in the early stages of pregnancy) are passed out in the urine. Monoclonal antibodies in the test bind to the hormone if it is present, and this is used to produce the colour change

Question 19

What are monoclonal antibodies used for?

Answer 19

diagnosis in pregnancy tests, in labs to measure levels of hormones and other chemicals in the blood to detect pathogens for research, and to identify or locate specific molecules in cells or tissue

Question 20

3 ways in which monoclonal antibodies are used to treat cancer cells

Answer 20

direct use to trigger the immune system to recognise, attack and destroy cancer cells, to block receptors on the surface of cancer cells and stop them growing and dividing, and to carry toxic drugs, radioactive substances or chemicals

Question 21

Advantage of monoclonal antibodies

Answer 21

they can deliver substances to cancer cells without harming other cells in the body

Question 22

Disadvantages of monoclonal antibodies

Answer 22

they have created more side effects than expected and are not yet as widely used as hoped when they were first developed