T3 - Fighting disease

Question 1

What is an antibody?

Answer 1

A protein produced by white blood cells in response to the presence of an antigen.

Question 2

What is an antigen?

Answer 2

A molecule on the surface of a cell or pathogen. Foreign antigens trigger white blood cells to produce antibodies.

Question 3

How does skin help to defend against disease?

Answer 3

It acts as a barrier to pathogens. It also secretes antimicrobial substances which kill pathogens.

Question 4

What substance does the stomach produce to kill pathogens?

Answer 4

Hydrochloric acid

Question 5

Which type of cells are part of the immune system?

Answer 5

White blood cells

Question 6

How do white blood cells attack pathogens?

Answer 6

Consuming them - White blood cells can engulf foreign cells and digest them. This is called phagocytosis.

Producing antibodies - Lock onto the invading cells so that they can be found and destroyed by other white blood cells.

Producing antitoxins - These counteract toxins produced by the invading bacteria.

Question 7

What is a vaccine made up of?

Answer 7

Vaccines involve injecting small amounts of dead or inactive pathogens.

Question 8

How do vaccines work?

Answer 8

They expose us to the antigens of a pathogen so that we can develop immunity to it.

Question 9

Pros of vaccines

Answer 9

Help control lots of communicable diseases.
Epidemics are prevented if a large percentage of the population are vaccinated.

Question 10

Cons of vaccines

Answer 10

Don’t always give immunity.
Can cause bad reactions (swelling, fever, seizures)

Question 11

What are painkillers?

Example

Answer 11

Drugs that relive pain but don’t tackle the cause of the disease or kill pathogens.
Eg. paracetamol, aspirin

Question 12

What are antibiotics?

Example

Answer 12

They kill (or prevent the growth of) the bacteria causing the problem without killing your won body cells.
Different antibiotics kill different types of bacteria.
Antibiotics don’t destroy viruses.
Eg. penicillin

Question 13

Which measures help to reduce the spread of antibiotic resistance?

Answer 13

Patients taking antibiotics for the full prescribed course
Doctors only prescribing antibiotics for serious bacterial infections

Question 14

What is antibiotic resistance?

Answer 14

Where the bacteria evolves so that antibiotics can no longer kill them.

Question 15

Aspirin

Answer 15

A painkiller to lower fever.
Developed from a chemical found in willow.

Question 16

Digitalis

Answer 16

Used to treat heart conditions.
Developed from a chemical found in foxgloves.

Question 17

Penicillin

Answer 17

Penicillin was discovered by Alexander Fleming when some Penicillium mould contaminated one of his Petri dishes.

Question 18

What does the term ‘efficacy’ mean?

Answer 18

How well a drug produces the desired effect

Question 19

What does the term ‘toxicity’ mean?

Answer 19

How harmful a drug is e.g. how many side effects.

Question 20

What does the term ‘dosage’ mean?

Answer 20

How much of the drug is required to give the desired effect?

Question 21

What are the stages of drug development?

Answer 21

1) drugs are tested on human cells and tissues.
2) The drug is tested on live animals. (2 in uk)
3) The drug is tested on healthy human volunteers, very low dosage is given to make sure there is no harmful side effects.
4) Drugs are tested on people suffering from the illness to find the optimum dose.
5) Patients are put in 2 groups, one is given the drug the other a placebo.
6) Clinical trials are double blind.
7) The results are peer reviewed to prevent false results.

Question 22

What is the optimum dose?

Answer 22

The dose of the drug that is the most effective and has few side effects.

Question 23

What are placebos and why are they used?

Answer 23

A substance that’s like the drug being tested but doesn’t do anything.
This is so the doctor can see the actual difference the drug makes.

Question 24

Why are clinical trials double blind?

Answer 24

Double blind trials are where the patient and the doctor doesn’t know who has received the placebo and who has received the real drug.
This is so the patients and the doctors who are monitoring patients and analysing results aren’t subconsciously influenced by their knowledge.

Question 25

What is the organism that penicillin originates from?

Answer 25

Penicillium Notatum

Question 26

What are the 3 factors that scientists research during drug testing?

Answer 26

Toxicity, efficacy, dosage

Question 27

How do hairs and mucus in your nose fight against disease?

Answer 27

Trap particles that could contain pathogens.

Question 28

How do the trachea and bronchi defend against disease?

Answer 28

Secrete mucus to trap pathogens.
Lined with cilia, wafts the mucus up to the back of the throat.