B6 - preventing and treating disease

Question 1

Describe how vaccines work?

Answer 1

1)Small amounts of dead or inactive pathogen, or even parts of the pathogen are put into your body- often by injection
2) antigens in the vaccine stimulate your white blood cells into making antibodies. The antibodies destroy the antigens without you getting the disease.
3)if the pathogen enters your body in the future, your white blood cells respond by rapidly producing antibodies. You are now immune to the disease

Question 2

What are antibiotics and who discovered the first one

Answer 2

-Antibiotics are substances which kill or inhibit the growth of bacteria.
-the first antibiotic was discovered by Alexander Fleming -penicillin

Question 3

How did Alexander Fleming discover penicillin?

Answer 3

-In 1928 Dr Alexander Fleming returned from a holiday to find mould growing on a Petri dish of Staphylococcus bacteria.
-He noticed the mould seemed to be preventing the bacteria around it from growing.
-He soon identified that the mould produced a self-defence chemical that could kill bacteria.

Question 4

What are the two types of antibodies?

Answer 4

-Broad spectrum antibiotics
-narrow spectrum antibiotics

Question 5

What are the main limitations of antibiotics?

Answer 5

-they are only effective against bacteria - not viruses
-not all antibiotics are effective against all bacteria.
-bacteria can mutate to develop resistance to antibiotics
-

Question 6

Why do bacteria become resistant to antibiotics?

Answer 6

As some doctors overprescribe them or patients don’t take them correctly.

Question 7

Why do we test drugs before use?

Answer 7

For toxicity, efficacy and doseage.

Question 8

What are the three stages of drug testing?

Answer 8

• preclinical testing (drug is tested on cells in a lab)
  -whole organism testing (drug tested on animals)
  -clinical trials (drug tested on human volunteers first then patients with the conditions)

Question 9

Describe the process of making monoclonal antibodies.

Answer 9

1) mouse is injected with specific antigen
2) specific B lymphocyte produces antibodies
3) we then fuse fast dividing cancer cells with these B lymphocytes to make a hybridoma
4) hybridomas then copy themselves rapidly .
5) the large quantity of hybridomas can then make the identical specific antibodies that we want

Question 10

What are some uses for monoclonal antipbodies

Answer 10

• pregnancy testing
• detecting diseases
• monitoring levels of specific substances
• research
• treating diseases

Question 11

Describe how monoclonal antibodies are used to make pregnancy tests.

Answer 11

When a woman is pregnant a hormone called HCG is produced which we can detect using monoclonal antibodies.
-when urine is added to the test that contains HCG, coloured antibodies bind to the HCG and travel up the test.
-these HCG-antibody complexes travel up the test to a strip covered by fixed monoclonal antibodies.
-these antibodies then bind to the HCG-antibody complexes forming a line of the coloured antibodies that are then visible to the user.