B6: Vaccination/Defence

Question 1

Explain the steps of how vaccines work and are made.

Answer 1

1) pathogen is destroyed/inactive and use the antigens
3) ingredients added to make vaccine
4) vaccine injected in body
5) white blood cells produce antibodies
6) memory cells remain in the body/produce antibodies rapidly on reinfection for this pathogen and can quickly destroy it

Question 2

What is a vaccine?

Answer 2

Weakened form of microbes that are given to bring immunity to a particular disease

Question 3

What are antibiotics?

Answer 3

A drug that kills bacteria inside the body

Question 4

What conditions are bacteria adapted to survive in? (5)

Answer 4

Nutrients (carbs,proteins,fats)
Moisture
Warm temperatures 
Oxygen 
pH (some survive in pH 7 but some survive in acid/alkaline conditions)

Question 5

What is a well-known superbug?

Answer 5

MRSA

Question 6

How do antibiotics kill bacteria?

Answer 6

There are different ways depending on the antibiotic:
1) Some antibiotics disrupt the production of the cell wall of the bacteria and they burst
OR
2) Others prevent the bacteria from respiring and they die

Question 7

The development of new antibiotics is costly and slow. Explain why. (3)

Answer 7

• every new drug needs to be tested
• there are many stages to antibiotic testing involving volunteers/animals to check safety
• some antibiotics don’t work or are not safe
• increasing overall cost of developing drugs

Question 8

Suggest how a vaccination programme would reduce the number of people with TB. Details of how a vaccine works are not required. (2)

Answer 8

• provides immunity

- stops the spread

Question 9

How does vaccination effect the body’s reaction to reinfection of the same pathogen?

Answer 9

• memory cells remain after 1st infection
• on reinfection, antibodies are made QUICKER
• GREATER number made
• antibody levels REMAIN HIGH for LONGER

Question 10

what is herd immunity?

Answer 10

if a large proportion of the population is IMMUNE to a pathogen,
the SPREAD IS REDUCED

Question 11

What is the difference between painkillers and antibiotics?

Answer 11

PAINKILLERS- relieves SYMPTOMS of the disease - can’t kill pathogens

ANTIBIOTICS- kills bacteria (NOPT VIRUSES)
- DON’T HARM HUMAN CELLS

Question 12

Why can’t antibiotics work against viruses?

Answer 12

• viruses live/reproduce inside cells

- difficult to develop drugs that kill viruses WITHOUT DAMAGING HUMAN CELLS

Question 13

Traditionally drugs were extracted from plants. Give 3 examples? (3)

Answer 13

heart drug DIGITALIS comes from FOXGLOVES
painkiller ASPIRIN comes from WILLOW
PENICILLIN comes from PENICILLIUM MOULD by Alexander Fleming

Question 14

What are drugs tested for?

Answer 14

TOXICITY - does it have harmful side effects?
EFFICACY- does it work?
DOSAGE

Question 15

a good medicine is …

Answer 15

effective
safe
stable
sucessful in taking/out of body

Question 16

What is preclinical testing and what does to test for?

Answer 16

• drugs tested on ANIMALS, CELLS,TISSUES in lab

- test for dosage, efficacy and toxicity

Question 17

What is clinical testing and what does to test for?

Answer 17

• drugs is tested on human volunteers with a LOW DOSE that is increased
• TEST FOR TOXICITY
• if safe they move on to testing on PATIENTS
• patients split into 2 group : one given a PLACEBO (double-blind trails)
• TEST FOR TOXICITY AND OPTIMUM DOSAGE

Question 18

Explain what are monoclonal antibodies? (2)

Answer 18

type of antibody which is specific to ONE binding site on ONE ANTIGEN.
target particular cells/chemicals in the body

Question 19

What allows monoclonal antibodies to target specific chemicals and cells in the body?

Answer 19

They are specific to 1 binding site on 1 protein antigen

Question 20

How are monoclonal antibodies produced? (5)

Answer 20

1) expose mice to the pathogen’s antigen
2) this stimulates lymphocytes in the mice to produce particular antibodies
3) the antibody is fused together with TUMOR CELLS, producing HYBRIDOMA cells
4) single hybridoma cells DIVIDE to make larger no. IDENTICAL CELLS, that all produce SAME ANTIBODY
5) these antibodies are collected

Question 21

uses of monoclonal antibodies and how it works? (4)

Answer 21

PREGNANCY/LFTs tests: Monoclonal antibodies are SPECIFIC to a hormone produced in pregnancy
they will BIND TO THE HORMONE if present/ produce COLOUR CHANGE

DIAGNOSIS/RESEARCH : monoclonal antibodies are SPECIFIC TO ANTIGENS found on pathogens. They contain MARKERS for doctors to locate them
FLUORESCENT DYE can be attached to the antibodies and detect specific molecules

Question 22

advantages of monoclonal antibodies ? (4)

Answer 22

• only bind to specific molecules so DON’T AFFECT HEALTHY HUMAN CELLS
• very specific so can be used to TREAT A RANGE OF CONDITIONS
• hoped to be cheaper in future
• tried/tested procedure

Question 23

disadvantages of monoclonal antibodies ? (3)

Answer 23

• caused MORE SIDE EFFECTS than expected at first
• EXPENSIVE
• producing specific antibodies is DIFFICULT

Question 24

what is a placebo drug?

Answer 24

an inactive substance that looks like the drug/treatment being tested.

Question 25

How do monoclonal antibodies cure cancer? TTT

Answer 25

• target specific antigen
• some trigger immune system to recognise specific cancer cell
• some carry toxic drug/radioactive substances to cancer cells without damaging others