Vaccination, Antibiotics and Painkillers Flashcards
What is vaccination
Vaccination involves introducing small quantities of dead or inactive
forms of a pathogen into the body to stimulate the white blood cells
to produce antibodies
Why can’t vaccination lead to a disease in a patient
Because the pathogen is dead or inactive, it cannot lead to the disease in the patient.
Describe how vaccination can prevent illness in an individual
Small quantities of dead or inactive forms of a pathogen are introduced into the body.
The white blood cells are now stimulated to produce antibodies against the dead or inactive pathogens
At the same time, the white blood cell divides by mitosis, to produce lots of copies of itself.
These copies of the white blood cell can develop into memory cells
If the same pathogen now enters the body, in the future, the white blood cells can produce the correct antibodies quickly. This prevents infection.
Describe how vaccination can prevent the spread of pathogens in a population
HERD IMMUNITY
If enough people are vaccinated, then there are fewer people to pass the disease on. This protects the unvaccinated people.
However, if a significant number of people are not vaccinated, then the spread of disease can spread through them. This risks epidemics
HERD IMMUNITY
If a large proportion of the population is ______ to a pathogen, the spread of the pathogen is much reduced
If a large proportion of the population is immune to a pathogen, the spread of the pathogen is much reduced
Define the term antibody
An antibody is a protein produced by white blood cells in response to the presence of an antigen
Define the term antigen
An antigen is a molecule on the surface of a cell or a pathogen
Foreign antigens trigger white blood cells to produce antibodies
Define the term antitoxin
An antitoxin is a protein produced by white blood cells that counteracts toxins made by invading bacteria
Define the term antibiotic
An antibiotic is a drug used to kill or prevent the growth of bacteria
Define antibiotic resistance
Antibiotic resistance is when bacteria are not killed by an antibiotic
Describe how certain diseases can be treated using antibiotics
Antibiotics kill infective bacteria inside the human body without harming body cells.
State some characteristics about antibiotics
It is important that specific bacteria should be
treated by specific antibiotics.
Antibiotics cannot kill viruses
What can doctors prescribe instead of antibiotics
Doctors can prescribe painkillers
What do painkillers do
Painkillers treat the symptoms of a disease by relieving pain, but do not kill the pathogens that cause it
Painkillers do not kill ______
They do not treat the disease itself
Painkillers do not kill pathogen
They do not treat the disease itself
Explain why antibiotics cannot kill viruses
Viruses live and reproduce inside human cells.
Because of this, it is difficult to develop drugs that kill viruses without also damaging the body’s tissues and cells.
Give an example of painkillers
Painkiller examples:
Paracetamol and Asparin
State an example of antibiotic
Example of antibiotic
Penicillin
Which drugs were extracted from plants
The plant foxglove was used to extract the heart drug digitalis
The painkiller aspirin was extracted from willow trees
Which drugs were extracted from microorganisms
Penicillin was discovered by Alexander Fleming from the Penicillium mould.
State the processes of drug development
Discovery
Pre-clinical testing (1st stage of testing)
Clinical trials
Describe the process of drug discovery
Drugs can be discovered from plants, microorganisms and Screening and Design
Describe the process of Pre-clinical testing
Firstly, we need to check the toxicity of the drug (in other words whether it is safe for humans). We then need to check that the drug is effective (it treats the disease that we are looking at). We need to work out the best dose of the drug
Preclinical testing is not carried out on humans. This is because the drug could be extremely toxic.
Instead preclinical testing is carried out on cells, tissues and on live animals .
Describe the process of clinical testing
Clinical testing is carried out on humans.
In the first stage of clinical testing, very low doses of the drug are given to healthy volunteers.
That is to check that the drug is safe in humans
If the drug is found to be safe, then clinical testing continues to find the optimal dose.
This is the best dose to treat the disease with the fewest side-effects.
In human trials, scientists use a double blind trial to see how effective the new drug is.
In a double-blind trial, the test group receive the active drug.
The placebo (control) group receive a dummy drug which looks exactly like the test drug but has no active ingredient.
In a double-blind trial neither the patients nor the doctors know which people are receiving the active drug and which are receiving the placebo.
This is to stop bias in case the doctors pay closer attention to people receiving the active drug.
The patient’s health is monitored carefully.
Define placebo
A placebo is a tablet or injection with no active drug in it.
Explain why some patients are going to get better when given a placebo
Some patients will get better if you give them a placebo. That is because they think they are being treated so they believe they are going to get better.
