SB5 Flashcards
What are pathogens
Microorganisms that cause diseases
What are communicable diseases
Diseases that can be passed from an infected person to other people
What are non-communicable diseases
Diseases that cannot be passed from person to person, they’re caused by our lifestyle or a problem in our body
How can one disease lead to another
One disease could damage the immune system
A disease could cause damage to defences
A disease that stops an organ from working properly
What is health
A state of physical and mental well-being
What is obesity
Condition when person someone has a BMI over 30, caused by a high fat and sugar diet
How can obesity increase the risk of cardiovascular disease
Fat can build up in the artery wall, making the artery narrower
How can smoking increase the risk of cardiovascular disease
Substances from tobacco smoke damage the artery lining
How can a blood clot increase the risk of a heart attack
A blood clot can block an artery, preventing blood flow
How can you reduce high blood pressure
Exercising more
Giving up smoking
Medicine
How can narrowed blood arteries be widened
A small mesh tube (stent) is inserted in the narrowest part
How can blocked arteries be fixed
Inserting other blood vessels so that the heart is supplied with oxygen and nutrients
What is cardiovascular disease
A disease that causes the heart and circulatory system the not function properly
List 3 ways pathogens can spread
Through water, eg cholera
Through the air, eg sneezes, water droplets
Through direct contact, eg HIV
How can you reduce the spread of pathogens
Washing your hands before eating Providing people with clean water Reduce direct contact with individuals Vaccination Isolation if the disease is highly infectious
What is chalara dieback
A communicable disease of ash trees caused by a fungus. A symptom is leaves dying earlier than usual
What is cholera
A communicable disease caused by bacterium. It spreads through water and causes diarrhoea
What is tuberculosis
A communicable disease caused by bacteria that infects the lungs
What is a vector
Organisms that carry pathogens from person to person
What is a capsid
A protein coat that surrounds a virus’ genetic material
What is lysis
When a cell membrane breaks open and releases everything within it
Explain what happens in the lytic cycle
1) Virus attaches to cell and injects its viral genetic material
2) Viral genetic material forms a circle
3) New viral genetic mater and proteins are assembled
4) The cell lyses, releasing viruses
Explain what happens in the lysogenic cycle
1) After the genetic material forms a circle, the viral genetic material inserts itself into the bacterial chromosomes
2) Bacterium reproduces with the viral genetic material
3) Viral genetic material separates from bacterial chromosome and this then goes into the lytic cycle
How can you study the effect of viruses on bacteria
Using bacterial lawn plates
What is nutrient agar
A thin layer where bacteria grows
What is the cuticle
The waxy layer on the outer surface of leaves
What is a chemical barrier
Use of chemical compounds to defend against attacks by pathogens, such as lysozyme and hydrochloric acid in humans, and poisons and insect repellents in plants
What is a physical barrier
A barrier that makes it difficult for pathogens to get into the body, such as skin, mucus and cilia in animals, and cuticles and cell walls in plants
What are examples of a physical barriers
Skin
Mucus
Hair
What are examples of chemical barriers
Toxins
Sweat
Urine
How are plants used medically
Used to kill pathogens
Used to produce medicines
What are aseptic techniques
Techniques used to keep away all microorganisms
What is distribution analysis
Looking at the pattern of where damaged plants occur to see what caused the damage
What can you use to identify stress in plants
Drones
What is lysozyme
An enzyme that breaks down cells walls of some bacteria
What is mucus
A sticky secretion in the lining of many openings that acts as a physical barrier
What are ciliated cells
Cells that carry dust and pathogens (substances) away
What can help identify an infection
Screening
What are antigens
Proteins on the outer surface of a cell
What are lymphocytes and what do they do
They’re a type of white blood cells with antibodies on their surface.
1) Antibodies that match the shape of the antigens on a pathogen attach to the pathogens which stops the pathogen from working
2) Lymphocytes divide over and over to produce identical clones
3) Some lymphocytes secrete antibodies that stick to the antigens and prevent pathogens from working
4) Other lymphocytes remain in the blood as memory lymphocytes
What do memory lymphocytes do
They remain in the blood and provide a faster second response if the same pathogen tries to infect again, making you immune to that pathogen
What do vaccines do
They contain weakened/inactive pathogens that include the antigens to trigger a response from white blood cells
What is herd immunity
When the majority of people are immunised so those that are not have a low chance of infection
Who discovered that mould made penicillin
Alexander Fleming
What is penicillin
The first type of antibiotic, made from mould
What do antibiotics do
Substances that kill bacteria
What is a problem with antibiotics
Bacteria are evolving to have resistance against certain antibiotics
List the stages of medicine development
Tested on tissues or cells in a lab
Tested on animals
Tested on humans (healthy small amount)
People with the disease will be given the medicine to work out the correct dose
How do pregnancy sticks work
They detect a hormone that is produced during pregnancy and are extra sensitive as the hormone is produced in small amounts. This is achieved by using antibodies to match the hormone (monoclonal antibodies)
Why can’t we use lymphocytes in pregnancy tests
After they release antibodies, they cannot divide anymore
What are hybridoma cells
The fusion of lymphocytes and cancer cells
How are hybridoma cells created
1) An antigen is injected into a mouse, the mouse produces lymphocytes
2) Cancer cells are grown in a culture medium
3) Cancer cell and lymphocytes fuse to form hybridoma cells, these can divide and make antibodies
Why are monoclonal antibodies so useful
- Can stick to any protein
- Can be made to match antigens on a pathogen (and thus identify it)
- Can be made to stick to specific cells
- Cancer drugs can be attached to them so they can be delivered to cells that need treatment (reducing the amount of drugs needed to kill the cells and risk of damaging healthy cells)
