Exam Questions Flashcards
(17 cards)
Describe how HIV is replicated.
1)Attachment proteins attach to receptors on helper T cell.
2)RNA enters the cell
3)Reverse transcriptase converts RNA to DNA.
4)Viral protein is produced.
5)Virus is assembled and released from the cell.
Describe how the human immunodeficiency virus (HIV) is replicated once inside helper T cells.
1)Reverse transcriptase converts RNA to DNA.
2)DNA is inserted into Helper T cell DNA.
3)DNA is transcribed into HIV RNA.
4)HIV mRNA is translated into new HIV proteins.
Describe how a phagocyte destroys a pathogen present in the blood.
1)Phagocyte engulfs pathogen.
2)Forms a phagosome
3)Fuses with lysosome
4)Enzymes hydrolyse the pathogen.
What is the role of the disulfide bridge in forming the quaternary structure of an antibody?
Joins two different polypeptides
Explain how HIV affects the production of antibodies when AIDS develops in a person.
1)Less antibody produced.
2)Because HIV destroys helper T cells
3)So few B cells activated.
Determining the genome of the viruses could allow scientists to develop a vaccine.
Explain how.
Mutation in the viral DNA.
Alters tertiary structure of viral attachment protein.
What is a monoclonal antibody?
Antibodies with the same tertiary structure. Produced from identical B cells.
Give one example of using monoclonal antibodies in a medical treatment.
Carries drugs to specific cells.
Describe the role of antibodies in producing a positive result in an ELISA test.
1)First antibody attaches to antigen.
2)Second antibody with enzyme attached is added.
3)Second antibody attaches to antigen.
4)Colour changes.
Describe and explain the role of antibodies in stimulating phagocytosis.
Do not include details about the process of phagocytosis.
Bind to antigen.
Attract phagocytes.
Describe how phagocytosis of a virus leads to presentation of its antigens.
Phagosome fuses with lysosome.
Virus destroyed by lysozymes
Antigens from the virus are displayed on the cell membrane
Describe how presentation of a virus antigen leads to the secretion of an antibody against this virus antigen.
Helper T cell binds to antigen.
Helper T cell stimulates a specific B cell.
B cell clones.
Forms plasma cells that release antibodies.
What is an antigen?
Foreign protein that stimulates an immune response.
What is an antibody?
A protein produced by B cells.
Describe how vaccination can lead to protection against bacterial meningitis.
1)Antigen attaches to a surface receptor on a B cell.
2)B cell divides by mitosis
3)Stimulated by cytokines
4)B cells release antibodies.
5)Some B cells become memory cells.
6)Memory cells produce antibodies faster.
When a vaccine is given to a person, it leads to the production of antibodies against a disease-causing organism. Describe how.
1)Vaccine contains antigen from pathogen.
2)Macrophage presents antigen on its surface.
3)T cell with complementary receptor protein binds to antigen.
4)T cells stimulates B cell.
5)With complementary antibody on its surface.
6)B cell secretes large amount of antibody.
Describe the difference between active and passive immunity.
1)Active involves memory cells, passive doesn’t.
2)Active takes time to work. passive is fast acting.
3)Passive is short term, active is long term.
4)Active involves production of antibody by plasma cells.
5)Passive involves antibody introduced into body from outside
