Unit 5 - Health, Disease And The Development Of Medicines Flashcards
What is WHO and what do they do?
The World Health Organisation
They are responsible for coordinating ways to improve health across the world.
According to WHO, what does good health mean?
‘Complete physical, social and mental well being’
What does physical well-being mean?
Free from disease, eating and sleeping well, not taking harmful substances and regular activity.
What is social well-being
How well you get on with other people and how they affect you.
What is mental well-being?
How good you feel about yourself.
Why might people with a lower income have a shorter life? (3)
They cannot afford a healthy diet, cannot access medical care, natural disasters mean more diseases and fewer doctors.
What is a disease?
A problem with a structure or process in the body that is not the result of injury.
How might a disease occur?
Microorganisms get into the body and change how it works.
What are pathogens?
Microorganisms that cause a disease
What are communicable disease?
Diseases that can be passed from an infected person to other people.
What is a non-communicable disease?
A disease that are not passed from person to person
What type of disease does a pathogen cause?
A communicable disease
What are non-communicable diseases caused by?
Our lifestyle, the way we live or a fault in our genes
What does correlated disease mean?
When a disease makes you more likely to get another disease
What are possible causes of correlations of a disease? (3)
Damaging immune system (easier for communicable diseases) damaging bodies natural barriers (can get into the body), stopping organs working properly (more likely for other diseases to occur)
What is a genetic disorder?
A genetic disease caused by faulty alleles of genes.
How are genetic disorders passed?
They are only passed to the offspring but not to any other person.
What is malnutrition?
Non-communicable diseases that occur when you get too little or too much of particular nutrients from your food.
What is a deficiency disease?
A disease caused by a lack in nutrients.
What disease can be caused by a lack of protein?
Kwashiorkor - enlarged belly
What disease can be caused by a lack of iron?
Anaemia - smaller red blood cells, tiredness
What disease can be caused by a lack of vitamin c
Scurvy - swelling and bleeding gums
What disease can be caused by a lack of calcium/vitamin d
Osteomalacia - soft and brittle bones
What is a drug?
A substance that changes the way the body works
What happens if an excess amount of ethanol is taken?
Liver diseases can occur including cirrhosis
Where is ethanol found?
In alcoholic drinks
What is the cost of treating people with liver disease?
£500 million each year
What is obesity?
A malnutrition caused by a diet that is high in sugars and fats.
What do we use fat for?
To store some vitamins and a store of energy.
What is cardiovascular disease?
A disease as a result of the circulatory system functioning poorly due to an increase in fat.
What is a sign of cardiovascular disease?
High blood pressure or even a heart attack.
What die BMI stand for?
Body Mass Index
What is the formulae for BMI
BMI = mass (kg)/ height^2 (m)
What BMI value is considered obese?
30 or above
What type of fat is closely linked to cardiovascular disease?
Abdominal fat
What method is better than your BMI at measuring your abdominal fat?
Waist-to-hip ratio
How do you work out your waist:hip
Waist/hip
How can tobacco smoke cause a build-up of fat in an artery? What disease can it cause,
Substances from the tobacco damage the artery lining.
Fat builds up in the artery wall where the lining was damaged.
A blood clot may block the artery or break off and block another part of the artery causing a heart attack or stroke.
This causes cardiovascular disease
How do substances from tobacco get into the blood?
When they are breathed in, they are absorbed by the lungs and transported around the body.
What is the main cause to cardiovascular disease?
A high blood pressure
How can a high blood pressure be treated?
Exercise more, give up smoking or be given medicines
How can narrowed blood vessels be widened?
By inserting a small mesh tube (stent) to hold it open.
New blood vessels can be inserted when arteries in heart are blocked so the heart tissue gets oxygen and nutrients.
Patients with these operations may be given medicines to help prevent heart attacks and strokes.
What does cholera cause
Severe diarrhoea
What is the pathogen that causes cholera
The bacterium Vibrio cholerae
What bacterium causes tuberculosis
Mycobacterium tuberculosis
What happens if you have tuberculosis
Damage the lungs resulting in blood specked mucus after coughing, fever and weight loss
What is a host of a disease
Something that is affected by the disease
What is a disease of Ashtrees caused by a fungus
Chalara dieback
What is a protist
One of the kingdoms
What protist causes malaria
Plasmodium
Why are viruses not true organisms
They don’t have a cellular structure
How do viruses multiply
By infecting a cell in taking over their cells DNA copying processes to make new viruses
What does Ebola virus cause?
The breakdown of blood vessels, liver cells and kidney cells. This leads to haemorrhagic fever
How does HIV attack the body
It attacks and destroys white blood cells in the immune system
Why can people with HIV develop AIDs?
Their immune systems cannot protect them from secondary infections
What are ulcers
Sore areas where bacteria attacks stomach lining
How do most pathogens spread?
From one host to another
How are colds and flus spread?
When people sneeze or cough, tiny droplets containing pathogens spread into the air which can last around a day
How does chalara dieback spread?
Strong winds carry chalara spores (cells that can grow into new organisms) over long distances.
Why are diseases such as typhoid more common in undeveloped areas?
Their water is not treated to kill the pathogens
What is hygiene?
Keeping things clean to remove or kill pathogens
How is helicobacter bacteria spread (2)
When people touch other people’s food after going to the toilet. Or from flies which have touched faeces and people’s food.
Why does Ebola virus require extreme hygiene practices?
The virus can easily enter people’s bodies through broken skin or eyes, nose or mouth.
Why did the Ebola outbreak in West Africa become epidemic?
Many people became infected by burning those who had died with the disease.
What does epidemic mean?
A widespread occurrence of an infectious disease in a community at a particular time.
How does a mosquito spread malaria?
The malaria protists are carried in their blood that they sucked from an infected person. They then inject the protist directly into the blood of the next person they feed on
What are vectors?
Organism that carry pathogens from one person to another
What do all viruses have?
One or more strands of genetic material surrounded by a protein coat, or capsid.
How do viruses make new genetic material and proteins?
They have to enter a living cell and take over the cells processes.
Give 2 viruses that invade the human body
HIV virus
Ebola virus
How does a virus make a new virus
The cell copies the viral genetic material to make new viral genetic material and proteins. These then make a new virus which escapes from the cell
Give 2 ways a virus escapes from the cell
Some completely breakdown the cell (lysis)
Others push through the membrane
Which pathway do viruses that cause lysis go through?
Lytic pathway
What is the lytic cycle?
Virus attaches to a cell and injects genetic material
The viral genetic material forms a circle
New viral genetic material and proteins are produced and assembled
The cell lyses releasing the virus
What is the lysogenic cycle?
After the viral genetic material forms a circle…
Viral genetic material injects itself into the bacterial chromosome
Bacterium reproduces replicating the viral genetic material
Cell and viral genetic material reproduce many times
Occasionally, the viral genetic material separates form the bacterial chromosome causing the lytic cycle
What are bacterial lawn plates?
A plate used to study the effect of viruses on bacteria
How do bacterial lawn plates work?
Bacteria grows on the nutrient agar. A solution containing viruses is added to the plate. After a day, two clear circles can be seen where bacteria have been killed by the viruses.
How is the cross-sectional area of a clear circle calculated?
Cross-sectional area = PiR^2
What is a physical barrier for a plant?
The cuticle, a waxy layer covering the surface of the leaves and stems.
How do some pathogens penetrate through the cell wall of a plant?
They release enzymes that soften cells walls
How do plants defend themselves against herbivores?
Using chemical defences like poison or insect repellents
Give an example of a chemical defence that a plant uses
A type of wild potato releases a substance into the air when attacked by aphids. This is very similar to the alarm substance that aphids release when attacked by a predator so they fly away.
Where was aspirin originally produced?
From salicylic acid made by many plants
Where was the medicine artemisinin which kills protists that cause malaria originally made from?
Wormwood plant
Where are most of today’s medicines made?
In a laboratory using chemical substances
What can be done to prevent the making of medicines be contaminated by the air
Using an autoclave to sterilise equipment and the growth medium
What is an autoclave?
A strong heated container
Give 5 conditions that are bad for plant growth
Too much water, too little water, not enough nutrients in the soil, diseases, pests
Give 4 things farmers look out for when looking for symptoms on plants
Change in growth, change in colour, blotching of leaves, lesions (areas of damage) on stems or leaves
How can plants of a wide area be affected by a disease
It can be spread by the wind
Give 2 tests that can be carried out when diagnosing a plant disease in a lab
Trying to grow a pathogen from damages crop plants
Using technology to identify the presence of genetic material from a pathogen
What might farmers also send when testing a plant for diagnosis
Soil samples to be tested for nutrients and toxins
A report about other observations
What is the most obvious physical barrier on a human?
The skin
Why can pathogens usually only cross the skin through wounds or when an animal pierces the skin?
It is difficult for the pathogen to penetrate the thick skin
What is a lysozyme?
An enzyme that breaks down the cell walls of some bacteria
Why is lysozyme a chemical defence?
It reacts with the substances in the pathogen to kill them or make them inactive
What additional defence does skin have?
It releases substances onto the skins surface to fight infections
Where is lysozyme secreted from
Tears, saliva, mucus
What is mucus?
A sticky secretion produced by cells lining openings like mouth and nose. It traps dust
What are ciliated cells?
Cells that are specialised to move substances such as mucus across their surfaces to carry dust and pathogens away
What substance is secreted from the cells lining the stomach and why
Hydrochloric acid to reduce the pH of stomach contents to about 2 so pathogens are destroyed.
What are STIs?
Infections where the pathogens are usually transmitted through sexual activities
Give 2 examples of STIs
Chlamydia, HIV virus
How can STIs be prevented
Using condoms
How can STIs be spread (3)
Mother to unborn baby
Sharing needles with an infected person
Sexual activity with an infected person
How can people with STIs be aware that they have it
Through screening
What are antigens?
Molecules found on the outer surfaces of all cells and virus particles
What does the immune system use antigens for
Identifying if something inside the bod is a cell of the body or has come from outside
What cells have antibodies on their surfaces
Lymphocytes (white blood cells)
How does the immune system attack pathogens?
A lymphocyte with an antibody that fits with the antigen is activated.
This causes the lymphocyte to rapidly divide to produce identical clones.
Some lymphocyte secrete large amounts of antibodies which stick to the antigens and destroy the pathogen.
Other lymphocytes remain in the blood ready to respond if the same antigen appears
What are memory lymphocytes?
Lymphocytes that remain in the blood.
Why is the secondary response of the immune system faster
There are already memory lymphocytes that can attack the pathogen faster
When are you immune to a pathogen
When your immune system kills the pathogen before you get ill
How do vaccines make you immune to a pathogen?
It contains weakened or inactive pathogens that include the antigens. This is injected into the body which causes a little reaction so that memory lymphocytes are made.
Why might a child not be given a vaccine?
If there is a known risk that a child might react badly
What is herd immunity?
When a large amount of people are immune making the rest also immune as there won’t be many people with the disease.
How did Alexander Fleming discover penicillin?
An agar plate that wasn’t washed was left for weeks. When her returned, some of the bacteria had been killed
What is an antibiotic?
A substance that either kills or inhibits their cell processes
Why are antibiotics useful for attaching bacterial infections that the immune system cannot control?
They do not target human cells
Why do different types of bacteria respond differently to a particular antibiotic!
They have different structures
Why do new medicines need to be developed to control the same bacteria?
The bacteria might have become resistant to it
What are the different stages of developing a new medicine?
Laboratory
Pre-clinical
Phase 1 clinical trial
Phase 2 clinical trial
What happens in the laboratory ?
A possible medicine is tested on cells or tissues in a lab. This is to check if the medicine will harm us and have the right effect
What happens in the preclinical trial?
The new medicine is tested on animals to see if it effects the whole body. To check side effects
What happens in phase 1 clinical trial?
It is tested on a small number of healthy people to check if it is safe and any side effects
What happens in phase 3 clinical trial?
The medicine is tested on people who have the disease to work out the dose and to check for any more side effects
What are bacteria static antibiotics?
Antibiotics that stop the pathogen
What are bactericidal antibiotics?
Antibiotics that kill the pathogen
How to bacteria static antibiotics work
They interfere with the multiplication process (stop translation so DNA is not replicated)
How do bactericidal antibiotics work?
They stop the cell walls from being made
Why are broad spectrum antibiotics not as good for humans?t
They target any bacteria - good or bad
Make you feel ill
Why don’t antibiotics kill viruses
They don’t have cell walls
They are inside a host cell
What are antiseptics?
Substances used to kill microorganisms on the surface of the body or equipment
Explain stage 1 of the core practical - Antibiotics
Use aseptic technique to pour an agar plate.
Open the bottle of bacterial culture and place the neck in a Bunsen flame.
Insert a sterile pipette a draw up a very small amount.
Gently add a couple drops into the Petri dish onto the agar.
Disinfect the pipette
Using a sterile spreader, spread the bacteria culture across the agar.
Explain stage 2 of the core practice - Antibiotics
Label 4 areas of the dish with the antibiotic you will use
Using a sterile forceps, place a sterile filter paper disk in the ‘control’ section.
Re-sterilise the forceps and place a paper disk with the antibiotic in each section.
Tape the lid
Explain stage 3 of the core practice - Antibiotics
Measure the diameter of the clear space around each disk and work out the radium to calculate the cross-sectional area.
Draw a graph showing the different cross sections and the different antibiotics
How do pregnancy tests work?
If a woman is pregnant, they produce a hormone called hGC. The antibodies on the stick have a blue bead attached to them. The antibodies on a pregnancy test stick bind to the hormone when a urine sample is added. The urine continues to move along the strip with the antibodies. At the test strip, there are immobile antibodies which the beaded antibodies bind to causing the blue dye to accumulate.
How is the extreme sensitivity of a pregnancy test made?
By using antibodies that match the hormone
What are monoclonal antibodies?
Identical antibodies that can be made to bind to a specific cell or chemical.
Why can monoclonal antibodies not be made in large amounts?
Once a lymphocyte begins to produce antibodies, it cannot divide anymore
What is a hybridoma cell
A cell made by fusing a normal cell with a cancer cell to create a cell with the desired properties
What are the stages of making monoclonal antibodies?
Take an animal and inject it with an antigen
Extract the lymphocytes that the mouse makes.
Fuse the lymphocytes with a growing tumour cello make a hybridoma cell
These then divide rapidly due to the cancer cell and gives your lots of identical antibodies called monoclonal antibodies.
What are platelets?
Fragments of blood cells that help to form blood clots but they can kill if they are in the wrong place
How can monoclonal antibodies be made for diagnosis?
The antibodies are made slightly radioactive. When they attach to a cancer cell, the radioactivity can be detected and the location of cancer can be found.
Why are monoclonal antibodies better at treating cancer than other drugs
They only attach to specific cells which can be made to be cancer cells so healthy cells are not affected. This reduces the amount of drug needed so reducing the risk.
