B6: Preventing and Treating Disease Flashcards
How are antibodies produced?
White blood cells make specific antibodies which bind to the antigens of the pathogen. If you come into contact with the same pathogen, memory cells make the same antibody more quickly.
How do vaccines work?
Vaccines involve injecting the body with a dead/weakened/inactivated form of a pathogen and the antigens stimulate your body’s immune system to produce antibodies against the pathogen.
This means if the same pathogen enters the body, white blood cells can produce the antibodies needed much more quickly, meaning you are now immune to the disease.
What is herd immunity?
It is when a large proportion of the population is immune to a disease, meaning the spread of the disease is reduced.
What are painkillers?
Painkillers such as aspiring are used to relieve you from the symptoms of the disease but do not kill the pathogens.
What are antibiotics?
They are medicines that work inside your body to kill bacterial pathogens. They damage bacterial cells without harming your own cells.
What are the disadvantages of antibiotics?
- They cannot kill viral pathogens as it would damage body cells as viruses live and reproduce in our cells.
- Bacteria are becoming more resistant to antibiotics and can still live and reproduce meaning new ones need to be discovered. To prevent this don’t overuse antibiotics.
What are have different drugs come from?
Digitalis is extracted from foxgloves.
Aspirin comes from willow trees.
Penicillin is an antibiotic discovered by Alexander Fleming whilst he was growing bacteria and noticed something prevented it from growing.
What is a good medicine?
One that is:
- Safe: must not be too toxic or have any negative side effects.
- Effective: must prevent/cure a disease or at least make you feel better.
- Stable: must be able to use medicine under normal conditions.
- Successfully taken into and removed from your body: must reach target and be cleared, important to know dosage as well.
How is a medicine/drug prescribed?
Preclinical Testing - takes place in a laboratory using cells, tissues and animals.
Clinical Testing - using healthy volunteers and patients who are given a low dose at first to check for side effects.
If the medicine passes the tests and trials, other scientists will peer review it and check for repeatability before it is then prescribed.
What is used during clinical testing?
Placebo is used as a control and doesn’t contain the drug to make sure that the drug is actually having an effect.
Single or double blind trials can be used when one or both of the patient and doctor don’t know whether it is the drug or not in order to remove bias when recording results.
What are monoclonal antibodies?
They are proteins that bind to antigens and are produced to target particular cells/chemicals in the body.
How are monoclonal antibodies produced?
- Scientists use mice lymphocytes that produce antibodies but don’t divide, which have been stimulated to produce a specific antibody.
- They are combined with tumour cells, which divide rapidly, to form a hybridoma cell which produces antibodies and divides rapidly.
- They hybridoma can then divide to produce clones of itself which all produce the same antibody and all bind to a specific antigen.
- The antibodies are then collected and purified.
How are monoclonal antibodies used in pregnancy tests?
Monoclonal antibodies will bind to the HCG hormone in urine made during a pregnancy and if present it will produce a colour change to signal a positive result.
How are monoclonal antibodies used for diagnosis of diseases?
They bind to the specific antigen of a pathogen and can carry fluorescent dye/markers to it to show where the pathogens are.
How can monoclonal antibodies be used for measuring/monitoring and research?
Measuring/monitoring - they can be used to measure or monitor the levels of hormones/chemicals in the blood.
Research - can be used to locate or identify specific molecules in cell/tissue.
How can monoclonal antibodies be used for treating disease?
They can trigger the immune system to attack cancer cells. Can block receptors on cancer cells to stop them dividing. Can carry toxic drugs/radioactive waste to stop tumours from dividing.
What are the advantages and disadvantages of monoclonal antibodies?
Advantages: healthy cells not affected and can treat many conditions.
Disadvantages: difficult to attach to drugs, expensive, could trigger an immune response.
