Complement Flashcards
Alternate pathway
Activated by invading microorganisms
Immediate response to infection
How is Enzymatic cascade started
Conversion of an initial protein to an enzyme
What happens after complement activation
Direct killing of bacteria
Phagocytosis of bacteria
Inflammation
What Ig’s are used in the classical complement pathway
IgM
IgG
What is C1
Binding site that turns from inactive to active protein when binded to
What does activated C1 do
Cleaves C4 into C4a and C4b
What does C1 do to C2
Cleaves it into C2a and C2b
What does C4b do
binds to cell surface
What does C2b do
binds to C4b and makes C3 convertase
What does C3 convertase do
Cleaves C3 into C3a and C3b
What does C3b do
Binds to bacterial cell surface
What does C3b do
binds C5b
What does C5b do
binds C6 and C7
What does the C5,6,7 complement do
Brings in C8
What does the C5,6,7,8 complement do
brings in C9 which creates a huge hole in the bacterial surface causing lysis
What is the C9 core formation called
MAC
What is sialic acid
Molecule on mammalian cell membranes that differentiates mammalian from bacterial cells
What happens when C3b sticks to a mammalian cell
H and I factors recognize Sialic acid and inactivate C3b
What happens in the alternate complemement path on a bacterial cell membrane
C3b brings in Bb
What is functionally similar to C4b2b in the alternate path
C3bBb
what is important about C3
C3 biggest and largest amount
What would happen if an animal didn’t have C3
Get sick from bacteria easier
Classical pathway
Activated by antigen-antibody complexes formed during adaptive immune responses
5-7 days