Fichas
Complement System - 3
Fichas del conjunto (56)
- 1What is complement?A series of plasma proteins which when activated, interact sequentially forming a self-assembling enzymatic cascade generating biologically active molecules mediating a range of end processes.
- 2How many proteins are there in complement?About 30
- 3In general terms what allows the control of complement?Regulatory factors
- 4What are the 4 complement pathways?1. Classical
2. Lectin
3. Alternative
4. Terminal - 5What are the 4 end effects of the terminal pathway?1. Cell lysis
2. Inflammation
3. Opsonization
4. Interact with other pathways - 6What is the key end product of the classical, lectin and alternative pathways?C3b
- 7What triggers the classical complement pathway?The binding of antibodies to the surface of an antigen
- 8What is the first component of the classical complement pathway?C1
(C1r, C1s, C1q) - 9Where does C1 interact with?The CH2 domain of the antibody
- 10What does activated C1s act on and what is created in the classical pathway?C4
C4a and C4b - 11What happens to C4a and C4b?a) Floats away
b) sits on the surface of the antigen - 12When will C1s act on C2?Once C2 has interacted with C4b on the surface of the antigen
- 13What is created by C2 caused by C1s?C2a and C2b
- 14What is C3 convertase in the classical complement pathway?C4b and C2b
- 15What does C3 convertase act on and what is made?C3
C3a and C3b - 16What does C3b attach to and what does this create?C3 convertase
Creates C5 convertase (C2b, C4b,C3b) - 17What is the end product of the classical complement pathway?C5 convertase
- 18What starts the lectin complement pathway?Mannan binding lectin
- 19What is created by the lectin pathway?Same as classical
- 20When is the lectin pathway likely to happen?When chemotactic or in anaphylactic
- 21Why is it necessary to control the classical and lectin pathways?Can be toxic if not required
- 22Give 6 ways in which the classical and lectin pathways are controlled?1. Short life of complement
2. C1 inhibitor dissociates r/s
3. C4 binding protein displaces C2b
4. Factor I causes inactive C4c/C4d to be made from C4b
5.Factor I causes inactive C3c/C3d to be made from C3b
6. Membrane DAF, Cr1 and MCP disrupt C3 convertase - 23How many phases does the alternative pathway occur in?2
(Tick-over and activation) - 24Where do the 2 phases occur in a cell?Tick over is fluid phase
Activation is on cell surface - 25What is required to allow the full activated phase to occur?Trigger factor
- 26What allows the formation of C3i from C3?Spontaneous proteolysis
- 27What combines with C3i?B
- 28What interacts with B to for Bb and Ba?D
- 29What is C3 convertase in the alternative complement pathway?C3i and Bb
- 30What does C3 convertase act on in the alternative pathway and what is created?C3
forming C3a and C3b - 31In a healthy cell what acts on C3b in the alternative pathway to create inactive forms C3c/C3d?Factors H and I
- 32What happens when the activated phase of the alternative pathway is activated?C3b is allowed to sit on the trigger surface of the cell
- 33What interacts with C3b on the trigger surface in the activated phase?B
- 34What breaks down B into Bb and Ba on the trigger surface of the cell?D
- 35What is added to C3b and Bb to create C3 convertase in the activated phase?P (properdin)
- 36What does stable C3 convertase act on in the activated alternative pathway? What is the name of this?More C3 to create C3b
Amplification loop - 37What is C5 convertase in the activated phase?P, C3b, Bb, C3b
End of activation phase - 38What is the starting molecule in the terminal complement pathway?C5 convertase
(doesn't matter which structural one) - 39What is added to C5b to create membrane attack complex?C5b, C6, C7, C8 and multiple C9
- 40What can inhibit the membrane attack complex?Mac inhibitor/ C59
- 41What is cytolysis?The breaking up of a cell
- 42What causes cytolysis?MAC (membrane attack complex)
- 43How does MAC cause cytolysis?1. Inserts itself multiple times in the phospholipid bilayer
2. Causes holes to appear
3. Leaky cell leading to osmotic imbalance
4. Ions dragged into cytoplasm from ECF
5. Water taken into the cell
6. Osmotic lysis - 44Does lysis occur more in bacteria or virus?Bacteria
- 45What happens to erythrocytes when they are cytolysised?Haemoglobin released to create a red coloured solution
- 46How can complement cause the generation of bioactive substances?C3a and C5a are involved in biological pathways
- 47Give 7 ways C3a and C5a can cause bioactive substances.1. Smooth muscle contraction
2. Mast cell degranulation
3. Local odema
4. Vasodilation
5. Local influx antibody and complement
6. Cell extravastion
7. Neutrophil activation
8. Attracted up chemotactic gradient - 48What are the 2 ways in which a marcophage can find what it should eb clearing out easier?1. Random encounter of larger molecules (caused by IgM)
2. Opsonisation - 49What is the cell that will phagocyse particulate antigens and immune complexes?Marcophage
- 50How does IgM create a larger molecule for removal?Valency of 10 and therefore can bind with more antigens
- 51In what 2 ways can opsonisation occur?IgG and C3b
IgG alone - 52How does opsonisation work?Macrophage has receptors C3bR and FcR which allows the molecules to be more easily recognised and therefore phagocysed.
- 53How do marcophages keep the blood clean?Immune adherence
- 54What do erythrocytes have that allows them to pick up 'garbage' and take them to macrophages?C3b receptors
- 55Which 2 organs are there lots of marcophages due to being vascular organs?Spleen
Liver - 56Is complement the only system that helps deal with inflammation?No
Información
- Descripción
- (Immunology MD) 2. Disease mechanisms and host responses AD1 Fichas sobre Complement System - 3, creado por Rachael Jones el 05/10/2016.
- Creado por
- Rachael Jones
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