Preventing and Treating Disease, The Digestive System and Enzymes

Question 1

What are antigens?

Answer 1

Unique proteins found on the outside of every cell.

Question 2

What are antibodies?

Answer 2

Structures which join up to antigens and destroy the pathogen which they are attached to.

Question 3

Why are you immune from a disease after encountering it?

Answer 3

Some white blood cells (memory cells) remember the right antibody needed to destroy a specific pathogen.

The next time you encounter it, the white blood cells will rapidly produce antibodies, preventing the pathogen from causing any serious damage.

Question 4

What is a vaccination?

Answer 4

A vaccination is a small amount of dead/inactive pathogen which is introduced into the body.

The white blood cells are stimulated to produce antibodies for this particular pathogen.

If you meet the pathogen again, the antibodies will be produced rapidly because you have encountered it before.

Question 5

What is herd immunity and why is it important.

Answer 5

Herd immunity is when a large proportion of the population has immunity against a disease.

It can cause cases in a disease to drop and even eradicate the pathogen.

Question 6

What are antibiotics?

Answer 6

Drugs used to treat bacterial diseases.

Question 7

Name two problems of antibiotics.

Answer 7

They do not kill viral pathogens, so they have no effect on diseases caused by viruses.

Resistant strains of bacteria are evolving which means that antibiotics used to kill a particular type of bacteria no longer have an effect.

Question 8

Where is digitalis extracted from?

Answer 8

Foxgloves.

Question 9

Where does the painkiller aspirin originate from?

Answer 9

Bark in willow trees.

Question 10

What are the four criteria for a good medicine?

Answer 10

Effective - it must cure a disease or help a patient feel better.

Safe - it cannot be toxic.

Stable - it can be stored and used under normal conditions.

Successfully taken into and removed from your body - it must reach its target and be cleared from the body if it works.

Question 11

What is preclinical testing?

Answer 11

Testing on cells, tissues and live animals in a laboratory.

Question 12

What is clinical trials?

Answer 12

Testing on healthy volunteers and patients.

Question 13

What is double blind trials?

Answer 13

Testing on healthy volunteers, but some are given a placebo to ensure that the results can not be tampered with in any way.

Question 14

What are hybridoma cells?

Answer 14

Hybrid cells producing by the fusion of an antibody producing lymphocyte and a tumour cell.

Question 15

What are monoclonal antibodies?

Answer 15

Proteins made to target a particular cell.

Question 16

Give an example of how monoclonal antibodies are made.

Answer 16

Mice lymphocytes (which have been stimulated with a particular antibody and cannot divide) are combined with tumour cells (which don’t usually make antibodies but divide rapidly). The monoclonal antibodies are separated and purified.

Question 17

How many types of antigens can monoclonal antibodies bond to?

Answer 17

They can only bond to one specific antigen.

Question 18

Name the five uses of monoclonal antibodies.

Answer 18

Pregnancy tests, diagnosis of disease, measuring and monitoring, research and treating disease.

Question 19

Why could monoclonal antibodies be useful in treating disease, most notably cancer?

Answer 19

They target only specific cells. The current cancer treatment is chemotherapy which attacks all fast growing cells in the body, resulting un unwanted side effects. Monoclonal antibodies would target only the cancer making them very effective.

Question 20

What are the three ways that monoclonal antibodies could treat disease?

Answer 20

Direct use to trigger immune response to attack.

Block receptors on cancel cells so they stop growing and dividing.

Carry toxic drugs that stop cells growing and dividing without causing harm to other cells.

Question 21

What are some advantages of monoclonal antibodies?

Answer 21

They only target specific cells in the body.

They can treat many conditions.

Question 22

What are some disadvantages of monoclonal antibodies?

Answer 22

They are very expensive.

More research is needed.

Producing the right monoclonal antibodies is a lot more difficult than expected.

Question 23

What is the digestive system?

Answer 23

A system of organs which breaks down food into smaller, soluble molecules so that they can be used by cells.

Question 24

What do enzymes in the digestive system do?

Answer 24

They break down large, insoluble molecules into small, soluble molecules.

Question 25

What are carbohydrates?

Answer 25

The most important food group which provides us with the energy that we need.

Question 26

What are carbohydrates broken down in to?

Answer 26

They begin as long chains of starch and cellulose (complex carbohydrates). Enzymes break them down in to simple sugars (glucose and sucrose).

Question 27

What are lipids?

Answer 27

The most efficient energy store and an important source of energy.

Question 28

What are lipids broken down in to?

Answer 28

They begin as being made up of carbon, hydrogen and oxygen, similar to carbohydrates, They are broken down in to molecules of fatty acids joined to a molecule of glycerol.

Question 29

What are proteins?

Answer 29

The food group which builds up cells and tissues in the body.

Question 30

What are proteins broken down in to?

Answer 30

They begin as one long chain known as a protein. They are broken down in to amino acids.

Question 31

How can you test for starch?

Answer 31

Iodine test. Yellow/red solution blue/black if starch is present.

Question 32

How can you test for simple sugars?

Answer 32

Benedict’s test for sugars. Blue solution turns brick red on heating if sugar is present.

Question 33

How can you test for protein?

Answer 33

Biuret test. Blue biuret reagent turns purple if protein is present.

Question 34

How can you test for lipids?

Answer 34

Ethanol test. Ethanol added to a solution gives a cloudy white layer if a lipid is present.