Topic 5 - Health, Disease and Development of Medicines Flashcards
disease
a problem with a structure or process in the body
pathogens
microorganisms that cause diseases
communicable disease
a disease that can be passed from an infected person to other people
non-communicable disease
can’t be passed from person to person
how are non-communicable diseases caused
caused by a problem in the body such as a fault in the genes or as a result of the way we live
how can a genetic disease be spread (non-communicable disease)
passed to offspring
cardiovascular disease
a disease caused by the circulatory system functioning poorly
how is cardiovascular disease caused
too much abdominal fat (malnutrition)
BMI equation
mass/ height^2
body mass index
way of measuring the amount of fat on someone
waist to hip ratio
dividing waist measurement by hip measurement (more effective than BMI)
how can a blood vessel be widened
using a stent
explain how virus’ spread
they multiply by infecting a cell and taking over the cell’s DNA-copying processes to make new viruses
how is tuberculosis spread (what type of disease is it)
through the air (airborne) - coughing and sneezing releases pathogens into & the air that infects other people
how airborne diseases be prevented from spreading
sneeze into tissue, wash hands, social distance, wear mask
how is chalara ash die back spread
can spread through the air (airborne) as tiny thigh spores (cells that grow into new organisms)
chalara ash die back
disease of ash trees caused by fungus
ways that pathogens can be spread
- air
- water
how is cholera spread (what type of disease is cholera)
waterborne
what causes cholera
poor hygiene - dirty water used for drinking, cooking and washing
vectors of a disease
organisms that carry pathogens from one person to the next
how is malaria spread
the mosquito injects the protist directly into the blood of the next person it feeds on
lysis
the disintegration of a cell by rupture of the cell wall or membrane
lytic pathway
the pathway that viruses that cause lysis go through
lysogenic pathway
reproductive cycle where viruses DNA integrates into the DNA of its host cell
area of inhibition
is a circular area around the spot of the antibiotic in which the bacteria colonies do not grow
lymphocyte
white blood cell
plant adaptation to protect them against a bacteria, fungi and viruses
they are covered by a waxy layer called the cuticle; this layer acts as a physical barrier which makes it difficult for pathogens to get to the cell beneath
how do pathogens enter if the cell wall is tough
they release enzymes that soften the cell wall
yeild
the amount of useful product
biological vector
objects that may carry pathogens that can multiply within their bodies and be delivered to new hosts
why was it difficult to prevent the spread of chalara ash die back
Because strong winds can carry chalara spores over long distances
How is Helicobacter spread?
- when people touch other peoples food after touching their mouth or after going to the toilet
- When the feet of flies that are fed and infected fetus then land on food
Name a bacteria that causes stomach ulcers as it’s the pathogen of the digestive system that spreads in food as well as water as it enters the body through the mouth (oral route)
helicobactor
what is the structure of a virus
contains one or more strands of genetic material surrounded by a protein coat (capsid)
virus
an infectious agent that can only replicate within a host organism (living cell)
what is an advantage of a plant only producing substance to protect itself when it’s attacked?
Producing the substances take energy so an advantage of only producing substances when attacked is energy conservation allowing for better growth and reproduction
two ways that substances from plants are used medically
- aspirin was originally produced from Celtic acid which the plant used to protect itself
- The medicine artemisinin which kills the plasmodium protist that causes malaria
Name aseptic techniques
- sterilising using an autoclave
- Using a Bunsen burner to sterilise the air
aseptic technique
strict procedures that healthcare providers use to prevent the spread of infection
why do cultures of bacteria in petri dishes and vials need to be kept covered?
to prevent contamination from environmental microorganisms and to minimise the risk of bacteria escaping into the environment
how can you tell if a plant is under stress?
Changes in growth, changes in colour or blotching of leaves or lesions on stems or lesves
lesion
area of damage
distribution analysis
Looks at where the damage plants occur
explain how to define identification of crop disease
send samples to a lab for testing and these tests can include trying to grow a pathogen from damage crop plants while using technology to identify the presence of genetic material from a pathogen
Diagnostic testing
A medical test or procedure that helps identify a persons disease or condition
how can soil samples and a field observation help the lab to make an accurate diagnosis?
They look for nutrients and toxins that can help the lab be more certain of the cause of a problem
three ways in which plant disease may be identified
- Disruption analysis
- Visual inspection
- Laboratory testing (pathogen diagnosis and soil samples)
lysozyme
an enzyme that breaks down the cell walls of some types of bacteria
where is lysozyme found
its secreted in tears, saliva and mucus where it helps to protect the thinner surfaces of the body
What are some physical and chemical barriers for pathogens?
- physical: the skin
- chemical: lysozymes
what is a cell that has an adaptation to help get rid of pathogens?
Ciliated cells specialised to move substances such as mucus across the surface this helps carry dust and pathogens away
why is lysozyme a chemical defence
because it reacts with substances in the pathogen and this kills the pathogen or makes them inactive
name defences against pathogens entering the body
- The stomach
- Ciliated cells
how is the stomach a good defence against pathogens entering the body?
some of the cells learning the stomach secrete hydrochloric acid reducing the pH of the stomach contents to about two - at this acidity, many pathogens are destroyed
antigen
any substance that causes your immune system to produce antibodies against it
where are antigens found?
They are attached to the outer surfaces of all pathogens
how does the immune system attack a pathogen
- pathogens have antigens on their surface that are unique to them
- A lymphocyte with an antibody attached to it will perfectly fit an antigen on a pathogen - this lymphocyte is then activated
- this lymphocyte divides over and over again to produce clones of identical lymphocytes
- Some of the lymphocytes secrete large amount of antibodies; the antibodies stick to the antigens and destroy the pathogens; other lymphocytes remain in the blood as memory lymphocytes ready to respond immediately if the same antigen ever turns up again
memory lymphocytes
Lymphocytes that stay in the blood so that if the same kind of pathogen tries to infect you again, they will cause a much faster secondary response - this means you are immune to that pathogen
what is a vaccine
A substance that simulates the bodies immune system to recognise and fight disease causing germs
What do vaccines contain and why?
A contain a weakened or inactive pathogen of a disease-causing germ in order to teach the body’s immune system how to fight of the disease
herd immunity
an indirect protection from an infectious disease that happens when the rest of the population is immune either through vaccination or immunity developed through previous infection
Explain how a vaccination can make you immune to the disease
Vaccination introduces a weakened form of the virus, prompting the immune system to produce antibodies and memory cells which provide immunity upon future exposure
Antibiotic
substances that could kill bacteria inhibit their cell processes which stops them growing or reproducing
What are the steps in developing in new medicine?
1) antibiotics go through a development phase
2) it’s tested on cells or tissues in the lab (pre-clinical stage)
3) if the first stage of successful the new medicine may be tested on animals
4) if that stage is successful the medicine is tested on a small clinical trial (a small number of healthy people) to check it safe and that the side effects is small
5) that stage of successful the medicine is then used in a large clinical trial, on many people who have the disease
6) placebo effect (double-blind trails)
Explain the pre-clinical stage of developing a new medicine?
The medicine is tested on cell or tissues - this is done because it shows if the medicine can get into the cells and have the required effect - it also make sure that harmful side effects are limited
Benefits of testing on animals
No risk to humans
Explain a small clinical trial and why do you have to do a small clinical trial before doing a large clinical trial?
Test the medicine on a small number of healthy people to check it safe and the side effects are small
What is a large clinical trial and benefits of doing a large clinical trial
Medicine is tested on people who have the disease and this helps to work out the correct amount to give and to check for different side effects on different people
Monoclonal antibodies
Identical antibodies (antibodies coming from a single origin)
How are monoclonal antibodies made?
1) a particular antigen (for example, a human hormone) is injected into a mouse the mouse produces lymphocytes that make antibodies against the human hormone
2) lymphocytes from the mouse fused with a cancer cell
3) the hybridoma cell can then both divide and make antibodies against the human hormone. These are monoclonal antibodies.
Hybridoma cells
Cells that are made by using a lymphocyte that produces the right kind of antibodies with a cancer cell
How come monoclonal antibodies used to identify where blood clot has formed in a patient’s brain?
- make down the body slightly radioactive
- When these antibodies attached to cancer cells, the radioactivity can be detected
How can monoclonal antibodies help for the treatment of cancer?
The cancer drugs can be attached to monoclonal antibodies so that they are delivered just to the cells that need treating - this reduces the amount of drugs needed to kill the cancer cells and reduces the risk of damaging healthy cells
why chlamydia be treated with antibiotics?
Because chlamydia is a communicable disease caused by bacteria that can be killed using antibiotics
how can HIV lead to the onset of AIDS
HIV destroys white blood cells which compromises the immune system making the person more susceptible to other diseases
What does HIV do
Destroys white blood cells
How does bacteria develop resistance to antibiotics?
- due to genetic mutation some bacteria are resistant
- The less resistant bacteria gets killed and some of the more resistant bacteria survives
- these more resistant bacteria starts to spread making more bacteria resistant
- offspring inherit this resistance
how does the use of antibiotics contribute bacteria developing resistance to antibiotics?
by people not completing their course of antibiotics
in the method of producing a bacterial culture on a petri dish, why do you have to allow the inoculating loop to cool?
so the bacteria are not killed
how do you investigate how good three different antiseptics were at killing bacteria
- soak a filter disc in each antiseptic and one with distilled water
- Place one disc in each quarter of the petri dish and label them
- Incubate the petri dish and leave it for awhile
- Calculate the zone of inhibition around each disc by measuring the radius and using the equation pi x r squared
- the antiseptic which killed the most bacteria will have the largest zone
how is the lytic pathway involved in the reproduction of viruses
- The virus inserts it’s genetic material into the host cell and takes over the host cell
- New viruses are made of virus components are assembled inside the cell
- The lyses to release the virus (host cell burst)
What are two ways the immune system will respond to an infection by a pathogen?
- Produce antibodies against antigens on a pathogen
- Produces memory lymphocytes
Describe how a doctor might determine if the child is growing as expected
- Measure the height/mass
- use a percentile growth chart to find the percentile for the child’s age -> this tells the doctor when most children their age are in terms of height
- Measurement should increase along a percentile
Explain how scientist could use an agar plate spread with the bacteria that causes a disease and disc containing different antibiotics to determine which antibiotic can kill the bacteria
- Place the antibiotic disc on the agar plate using aseptic techniques
- incubate the plate for 24 hours
- Measure the zone of inhibition
