specific immune system Flashcards
1
Q
what are antibodies
A
- glycoproteins called immunoglobulins
- bind to specific antigen on pathogen that has triggered the immune response
2
Q
what are antibodies made up of
A
- 2 identical long polypeptide chains (heavy chains)
- 2 identical short chains (light chains)
- chains held together by disulfide bridges
- polypeptide chains also held together by disulfide bridges
3
Q
what is the binding site of an antibody
A
- area of 110 amino acids
- variable region- has a different shape on each antibody which gives it specificity
4
Q
constant region of an antibody
A
the rest of the antibody molecule which is always the same (excluding the binding site which is the variable region)
5
Q
how do antibodies defend the body
A
- antigen-antibody complex acts as an opsonin so the complex is engulfed by phagocytes
- pathogens cannot invade cells whilst in an antigen-antibody complex
- antibodies act as agglutinins causing pathogens carrying antigen-antibody complexes to clump together which prevents them spreading and makes it easier for phagocytes to engulf them
- antibodies act as anti-toxins and bind to toxins to make them harmless
6
Q
where do T lymphocytes and B lymphocytes mature
A
T lymphocytes- thymus gland
B lymphocytes- bone marrow
7
Q
T helper cells
A
- have CD4 receptors which bind to antigens on APCs
- produce interleukins (cytokine) which stimulate activity of B cells
- this increases antibody production
- this stimulated production of other T cell types
- this attracts/stimulated macrophages to ingest pathogens with antigen-antibody complexes
8
Q
T killer cells
A
- destroy pathogen carrying the antigen
- produce hydrogen peroxide and perforin which kills pathogen by making holes in cell membrane
9
Q
T memory cells
A
- live for a long time
- part of immunological memory
- when they meet antigen the 2nd time, they divide rapidly to form clones of T killer cells
10
Q
T regulator cells
A
- suppress, control, regulate immune system
- stop immune response once pathogen dies
- make sure body recognises self antigens and does not set up autoimmune response
- interleukins also help control this
11
Q
Plasma cells (type of B lymphocyte)
A
- produce antibodies to particular antigen
- only lives for a few days
12
Q
B effector cells
A
divide to form plasma cell clones
13
Q
B memory cells
A
- live for a long time
- part of immunological memory
- remember specific antigen and enable body to respond rapidly when antigen is encountered again
14
Q
clonal selection
A
the selection of a specific lymphocyte after exposure to specific antigen
15
Q
clonal expansion
A
proliferation (rapid increase in numbers) of specific cells with the appropriate antibody for the antigen
