Chapter 6 Flashcards
What is an antigen?
a molecule that generates an immune response
What is the process of phagocytosis?
- phagocytes circulate body
- comes into contact with foreign antigen starts pahgocytosis
- attaches to foreign cell and cytoplasm engulfs it in phagocytic vacuole
- lysosome attaches and releases lysozymes which digest foreign cell
- phagocyte then presents antigen of foreign cell to stimulate immune response
What immune response is
- humoral
- cell mediated?
- humoral = b cells
- cell mediated = t cells
What is the role of t-helper cells?
- stimulate phagocytes to carry out phagocytosis
- stimulate the production of t-killer cells
- stimulate b cells to divide
What is the role of t-killer cells?
produce a protein that punctures an infected cell then secretes toxins and enzymes that kill the cell
What is the function of b cells?
- covered in antibodies - each b cell = different antibodies
- produce memory cells
- produces plasma cells
What is the role of memory cells?
to remember the shape of the antigen needed to join onto a specific antibody - stay in circulation
What is the role of plasma cells?
b cell that rapidly produces lots of antibodies need for a particular antigen - monoclonal antibodies
What is an antibody?
protein produced as an immune response that binds to antigens to form an antibody-antigen complex
What is the structure of an antibody?
- y shape
- antigen binding site t the top
- receptor binding site at the bottom
What is a primary immune response?
- antigen enters body for the first time - not recognise so slow
- production of t/b cells
- plasma and memory cells produced
What is a secondary immune response?
- antigen re-enters body - recognised
- quick immune response
- plasma cells produce lots of antibodies
What is active natural immunity?
becoming immune by catching disease and fighting it off naturally
What is active artificial immunity?
becoming immune through vaccination of dead or inactive antigens
What is passive natural immunity?
immunity gained as a baby due to antibodies received from mother through breast milk and placenta
What is passive artificial immunity?
immunity gained through introduction of someone else’s antibodies
What is herd immunity?
when enough people are vaccinated the spread of disease is reduced so those not vaccinated are still less likely to catch it
What are some ethical issues surrounding vaccinations?
- religious arguments
- cost
- testing
- side effects
- not working
What is the structure of HIV?
- surrounded by envelope
- attachment proteins sticking out
- capsid surrounds genetic material
- reverse transcriptase attached to genetic material
How does HIV cause symptoms of AIDS?
- people with HIV are considered to have AIDS when symptoms of their failing immune systems show
- destroys all t cells so body not protected against anything
Why are antibiotics ineffective against HIV?
invades host cell meaning it has no enzymes or ribosomes to interfere with
What does HIV use to stay in the body?
- invades t-helper cells
- t-helper = produce t-killer, phagocyes and b cells
- without t-helper no immune response
How does the ELISA test work?
- HIV antigen bound to well late
- blood plasma added - if HIV antibodies present they will bind to HIV antigen
- well washed to remove unbound antibodies
- second antibody added with enzyme attached - binds to HIV
- well washed then solution added with substrate that binds to enzyme on antibody
- colour = HIV
How do monoclonal antibodies help medication target specific cell types and give an example.
- it is possible to bind specific drugs to monoclonal antibodies which enable them to target specific cells
- anti-cancer drug attached to the monoclonal antibodies that bind to tumor markers on cancer cells
