immunology Flashcards
What is the role of a disulphide bridge in forming the quaternary structure of an antibody?
joins 2 different polypeptides
Describe how phagocytosis of a virus leads to presentation of its antigens
- phagosome fuses with lysosome
- virus destroyed by lysozymes
- antigen displayed on cell membrane
ADC is a drug that binds to antigens on tumour cells. Some of the antigens found on tumour cells are also found on healthy cells. use this info to suggest how ADC causes side effects.
- ADC binds to heathy cells
- causing damage to healthy cells
NMO is a disease that leads to damage of nerve cells in spinal cord. person with NMO produces anti-AQP4 antibody that only attacks these nerve cells. explain why anti-AQP4 antibody only damages these cells.
- anti-AQP4 has specific tertiary structure
- complementary to one antigen
- antigen only found on these nerve cells
- so antibody only binds to antigens on these nerve cells
Treatment for NMO involves monoclonal antibodies. structure of variable region is identical to anti-AQP4 variable region. use this info and your knowledge to suggest how monoclonal antibody prevents anti-AQP4 damaging cells.
- monoclonal antibody binds to antigen on nerve cells
- no damage caused when antibody binds
Explain how HIV affects production of antibodies when AIDS develops in a person
- HIV damages Th cells
- less B cells stimulated
- so less antibody produced
Describe how HIV is replicated once in Th cells
- RNA converted into DNA using reverse transcriptase
- DNA inserted into Th cell
- DNA transcribed into HIV mRNA
- HIV mRNA translated into new viral proteins
Describe the role of antibodies in producing a positive result in the ELISA test
- first antibody binds to antigen
- second antibody with enzyme attached is added
- second antibody binds to antigen
- substrate added and colour changes
