B6-Preventing and treating disease Flashcards
(31 cards)
What do lymphocytes do, and what shape are they?
Lymphocytes produce antibodies
Their shape is always complementary to their antigen
What is an antibody?
A chemical produced by a lymphocyte in response to an antigen
What is an antigen?
A marker on the surface of a microorganism that causes the body to produce antibodies, as it is seen as foreign
How do antibodies work?
They immobilise microorganisms by clumping them together which reduces symptoms and the spread of infection
The clump is destroyed by phagocytosis
What are memory cells and what is their role?
They are specialised white blood cells that have copies of the correct antibody for a particular antigen
They remain in the bloodstream after the first pathogenic infection which means that the pathogen can be destroyed quickly on the second infection before symptoms appear
After a vaccine/initial exposure to a pathogen, why is there a time lag before antibodies are produced?
It takes time to find the lymphocyte that produces the complementary antibody to the antigen
What is a vaccine?
A substance containing disabled antigens of a particular disease, usually administered via injection. Vaccines stimulate the body to produce antibodies to provide immunity against that disease.
After a vaccine, if a person contracts the pathogen, what happens and how does it differ in comparison to the initial exposuer?
The complementary antibodies are produced at a faster rate due to the presence of memory cells
The antibodies remain for longer
The antibodies are high affinity
More antibodies are produced
What do antibiotics do?
A substance that controls the spread of bacteria in the body by killing them or stopping them reproducing.
How do antibiotics work?
They inhibit the cellular processes of bacteria whilst no harming the host cells or healthy cells
Why do antibiotics not work on viruses?
Because viruses reproduce inside the host cells
Why is developing antiviral drugs difficult?
Because they may damage the host cell while killing the virus
What do antiviral drugs do?
They slow down viral development
What does a bacteriostatic antibacterial do?
Slows/stops growth and reproduction of bacterial cells
What does a bactericidal antibacterial do?
Kills bacteria
What is the drug derived from foxglove called and what does it do?
Digitalis and digoxin
They strengthen the heart beat
Where does aspirin come from and what does it do?
Willow tree bark
It acts as a pain-killer and an anti-inflammatory
What did Alexander Flemming do?
Discovered penicillin from mould on a petri dish
What are the 3 main components that must be considered when developing a new drug and what do they mean?
Efficacy-They must make you feel better
Toxicity-They must not be toxic or have many side-effects
Stability-They must be able to be used under normal conditions and stored for a long time
What must a new drug be able to do once inside the body?
It must be able to reach the site of action and then be cleared from the system once it has finished its job
What are double blind trials?
When neither the patients nor the doctor know who has been given the drug, and who has been given the placebo
Why is a double blind trial useful?
Reduces bias when interpreting results
Removes false symptoms/improvements in condition due to placebo effect
What is a placebo?
A fake of the real drug
How are monoclonal antibodies made?
An antigen is injected into a mouse’s spleen
B cells producing the desired antibody are isolated and extracted from the spleen
B cells are fused with cancerous myeloma cells which creates a hybridoma cell
This hybridoma cell can produce many antibodies and divide continuously to form clones
The desired hybridoma cell is isolated and allowed to divide to form a large number of cells
