Chapter 6 - Preventing and Treating Disease

Question 1

What is an antigen?

Answer 1

A protein on the surface of a cell.

Question 2

What is an antibody?

Answer 2

• Cells that deactivate or destroy pathogens inside the body.

Question 3

How does a vaccination work?

Answer 3

• Dead/inactive forms of a pathogen enter the body, stimulating the body to produce white blood cells. The next time the same pathogen enters the body, WBC will produce antibodies quicker.

Question 4

Give an example of 1 viral and 1 bacterial disease you can be vaccined against.

Answer 4

• Tetanus, Diphtheria (Bacterial)
• Measles, Mumps (Viral)

Question 5

What is the purpose of painkillers?

Answer 5

• To supress pain from a disease.

Question 6

Explain the main difference between paracetamol and penicillin.

Answer 6

• Paracetamol only supresses any pain caused by the disease
• Penicillin kills the bacteria causing the disease.

Question 7

What is an antiseptic mainly used for in real life?

Answer 7

• Cleaning cuts and wounds on the skin.

Question 8

What are antibodies used for in real life?

Answer 8

• Killing bacteria causing a disease.

Question 9

All new drugs are tested for efficacy, toxicity and dosage. Define these three terms.

Answer 9

Efficacy - If the drug can treat the disease
Toxicity - Any present side effects.
Dosage - Concentration of the drug

Question 10

What 3 things should a good medicine be?

Answer 10

• Effective: Should prevent or cure a disease
• Safe: Drug must not have too many side effects
• Stable: Ability to use and store the drug comfortably

Question 11

Describe the process of developing drugs (6)

Answer 11

• During pre-clinical trials, drugs are tested on cells and animals to ensure safety and toxicity of the drug. (1)
• Phase 1 clinical trials include young, healthy volunteers that the drug is tested on to check for any side effects. (1)
• Phase 2 includes testing the drug on current patients to check whether the drug can treat the disease.(1)
• Phase 3 includes testing the drug on a large number of people. (1)
• Double Blind Trials are when neither the patient or the doctor knows if they have received a fake or real drug. (1)
• The fake drug is called a placebo (1)
• This prevents any biased results from the phase 3 trails, to make sure the drug is good to go (1)

Question 12

What is a monoclonal antibody?

Answer 12

• A clone of a cell which can bind onto specific proteins, so they can target specific cells in the body.

Question 13

What are monoclonal antibodies produced by?

Answer 13

• Stimulating mouse lymphocytes to make a specific antibody.

Question 14

How do hybridoma cells contribute to the production of monoclonal antibodies?

Answer 14

• They divide to produce a large number of identical cells, all producing the same antibodies.

Question 15

How are monoclonal antibodies used in the treatment of diseases?

Answer 15

• They have been developed against antigens on cancer cells.

Question 16

Why did people think that monoclonal antibodies could be used in treatments of disease such as cancer?

Answer 16

• Monoclonal antibodies would only target a specific type of cell/chemical. (1)

Question 17

In phase 1 testing, only healthy volunteers are used

Suggest one reason for this.

Answer 17

• To ensure that any side effects of the drug will be clearly shown from the healthy patient.

Question 18

State what a placebo drug is.

Answer 18

• A drug that looks identical but doesn’t contain the active ingredient.

Question 19

Explain why are antibiotics not used to treat viruses.

Answer 19

• Viruses reproduce in the cell. This means that the antibiotics cannot destroy the viruses without damaging other cells.

Question 20

Describe how a pregnancy test works in terms of monoclonal antibodies (6)

Answer 20

• Urine contains hCG molecules (1)
• The HCG binds to antibodies with blue dye attached (1)
• The antibodies move down the test strip to the result window (1)
• hCG specific anitbodies bind to the result window, which turns blue (1)
• Remaining antibodies from the result window bind to immobilised antibodies specific to the mobile antibodies in the control zone (1)
• If both the control and result window are coloured, the test is positive. if only one is coloured, the test is negative.