Topic 5 - Health, Disease and Development of Medicines

Question 1

Define ‘Health’

Answer 1

A state of complete physical, mental and social wellbeing

Question 2

Define ‘Disease’

Answer 2

A condition where part of an organism doesn’t function properly. These can be communicable/non-communicable

Question 3

What is the difference between communicable and non-communicable disease?

Answer 3

Communicable diseases can be spread between individuals

Question 4

What is the role of the immune system? (in protection against disease)

Answer 4

If you are affected by one disease, it could make you more susceptible to others as your immune system is weakened so less able to fight off others

Question 5

Can you name some examples of non-communicable diseases?

Answer 5

Heart disease
Cancer
Liver disease

Question 6

Can you name some examples of communicable diseases?

Answer 6

Cholera
Tuberculosis
Malaria
Stomach ulcers
?
Ash dieback

Question 7

Define the term ‘Malnutrition’

Answer 7

When an organism isn’t getting the right food and nutrients needed to survive

Question 8

What is the purpose of the immune system?

Answer 8

To attack harmful pathogens to destroy them. Most important part is white blood cells which are in your blood looking for pathogens triggers correct immune response.

Question 9

What is the link between alcohol and liver disease?

Answer 9

Alcohol consumption damages the liver which stops it being able to carry out its function

Question 10

How may a poor diet lead to malnutrition?

Answer 10

Too many or too few nutrients leads to malnutrition (eg. scurvy - not having enough vitamin C)

Question 11

What are the effects of liver disease at a local, national and global scale? and other non-communicable diseases

Answer 11

Local - puts pressure on resources of local hospitals
National - NHS have a lot of pressure on resources, reduction of people at work put pressure on economy
Global - problems of diseases at global level, deaths in developing country and hold them back

Question 12

How is BMI calculated?

Answer 12

Weight / height squared

Question 13

Describe how obesity and cardiovascular disease are related? And smoking?

Answer 13

If you eat too many fats and sugars, they build up as excess energy and fatty deposits which block arteries causing blood clots to form damaging arteries and making the heart oxygen deprived.
With smoking, it builds up in lungs also stopping oxygen being transported.

Question 14

How can cardiovascular diseases be treated?

Answer 14

Improving lifestyle by eating healthily, exercise, drugs to reduce risks of CVD and if surgical procedures are necessary to repair damage of bleeding clots and infection.

Question 15

Name some diseases caused by bacteria

Answer 15

Cholera
Tuberculosis
Stomach ulcers

Question 16

Describe a disease caused by a virus

Answer 16

Ebola - via bodily fluids, fever with bleeding - isolate them

Question 17

Describe a disease caused by a protist

Answer 17

Malaria - damages red blood cells - mosquitoes - mosquito nets

Question 18

Describe a disease caused by a fungus

Answer 18

Cholera / Ash dieback - ash trees, leafless, through air, remove infected trees

Question 19

How can pathogens be spread? (with examples and prevention)

Answer 19

Through water - cholera - clean water
Mosquitoes - malaria - nets
Though air and wind - ash die back and tuberculosis - isolate
Bodily fluids - Ebola - isolate infected

Question 20

What is the structure of a virus?

Answer 20

Protein coat around a strand of genetic material. They are NOT cells. Cells have a nucleus, these don’t.

Question 21

What is the lytic pathway of a virus life cycle?

Answer 21

1) Virus attaches to host cell and injects genetic material
2) The proteins and enzymes in the host cell replicate the genetic material to produce new components of virus
3) These components assemble
4) Host cell splits open and releases new viruses killing host cell and starting more infections on cells.

Question 22

What is the lysongenic pathway of a virus life cycle?

Answer 22

1) Injected genetic material is part of cells genome (DNA)
2) Viral genetic material gets replicated along with the .hosts DNA every time the cell divides but virus is still dormant so no new virus are made
3) Eventually a trigger causes the viral genetic material to leave genome and enter lytic pathway

Question 23

Describe some physical barriers of plants and animals to pests and pathogens

Answer 23

Skin - blood clots quickly to seal cuts
Hairs - trap particles containing pathogens
Waxy cuticle - on leaves and stems
Cell walls - control what enters

Question 24

Chemical barriers of plants and animals?

Answer 24

Aspirin - relieves pain, fever found on bark of willow
Quinine - bark of cinchona tree cures malaria
Lysozyme - in tears kills bacteria on eye surface
Hydrochloric acid in stomach kills unwanted pathogens

Question 25

Describe the aseptic technique and what it is used for

Answer 25

1) Sterilise petri dish to kill microorganisms present
2) Sterilise inoculating loop by passing through flame
3) Transfer bacteria with loop to agar jelly in petri dish and quickly put lids on dish and sample you got bacteria from to prevent microbes entering.
4) Tape lid on and store upside down to stop condensation getting onto agar place. 48 hours 25°C
This is used to transfer bacteria in lab and grow it
Investigate effect of substances (antiseptics and antibiotics) and test

Question 26

How are plant diseases detected with visible symptoms?

Answer 26

• Environmental causes like nutrient deficiencies (yellow leaves) so add more nutrients to the soil
• By changing environment it can be possible to find out if plant is diseased or if symptoms are due to something else

Question 27

How does distribution analysis help identify plant disease?

Answer 27

Pathologists analyse distribution of diseased plants to find out what pathogen is involved eg. a patch could just be soil but random could be an airborne pathogen

Question 28

How can plant diseases be detected in a lab?

Answer 28

• Detecting antigens - (molecules on surface of pathogens) particular to each pathogen
• identifying antigen (pathogen) diagnosis
• Detecting DNA - studying DNA in plant tissue. To find pathogen.

Question 29

How can we reduce/prevent spread of STI’s?

Answer 29

Using physical barriers - condoms
Chemical barriers - contraceptive pill, implants
Don’t share needles
Medication

Question 30

How do antigens trigger the release of antibodies and production of memory lymphocytes

Answer 30

• Antibodies are produced when B-lymphocytes detect antigen on a pathogen
• Antibodies attach to invading pathogen so it can be found and killed by white blood cells. Antibodies produced are specific to that pathogen.
• Memory lymphocytes are produced in response to foreign antigen and remember it so on the second infection the person is now immune as there is a faster response.

Question 31

How does immunisation protect against infection by pathogen?

Answer 31

It stops you getting infections by injecting dead/inactive pathogens into the body - so even though they are harmless, your body makes antibodies to destroy them and triggers memory lymphocytes to be made for a faster secondary immune response.

Question 32

What are the pros and cons of herd immunity?

Answer 32

Pros - Prevents outbreaks/epidemics if large amount of population are immunised as those who aren’t are unlikely to get it as people immune can’t pass it on.
- Can wipe out diseases entirely
Cons - Doesn’t always work
- Can have a bad reaction to a vaccine

Question 33

What is an antibiotic? And why is it useful to treat bacterial infections but not other types of pathogens?

Answer 33

• Antibiotics treat bacterial infections by inhibiting cell processes in bacteria but not the host organism to prevent them from dividing.
• Can’t be used on viruses as they produce in body’s cells which is harder to not harm host organism.

Question 34

What are the stages of developing new medicine?

Answer 34

• Preclinical tests - on human cells and tissues in lab, then tested on live animal to find dosage (not toxic)
• Clinical test - if drug passes the test above then human volunteers test drug on healthy volunteers
• then tested on ill volunteer
• the patients randomly split and one given drug and one placebo. Blind as neither doctor or patient know. So results are not influenced by subconscious.

Question 35

What is a monoclonal antibody?

Answer 35

Identical antibody which are produced by B-lymphocytes to target specific protein antigen.

Question 36

What is a hybridoma cell?

Answer 36

Fusion of B-lymphocyte (from mice) with tumour cell (called myeloma) which can be cloned to get lots of identical cells which divide very quickly to produce antibodies (these can be collected)
Only target specific cell or chemical

Question 37

How are monolonal antibodies produced by B-lymphoctyes?

Answer 37

Lots of clones of a single lymphocyte, but it doesn’t divide very easily - takes time

Question 38

How are monoclonal antibodies used in diagnosis of disease? (blood clots) (cancer)

Answer 38

Blood clots - diagnose - antibody labelled with radioactive sample and passed to patient on drip into blood and around body

• when comes into contact with cancer cells it binds to tumour which shows on screen detecting sample to find exact spot and size
• can also be used to find blood clots

Question 39

What are the advantages of monoclonal antibodies compared to drug and radiotherapy to target cells?

Answer 39

• They only bind to specific cells (so cancer cells)
• Kills cancer cells and not host cells whereas radiotherapy does
• Side effects are lower than drugs or radiotherapy
• Radiotherapy and drugs effect normal cells.