Complement System- Classical Flashcards
During the activation of the CLASSICAL pathway, what is the first component that is activated?
C1
What are the 3 subunits of C1?
q,r,s
What are the 3 subunits of C1 bound together by?
Calcium
_ molecules each of C1r and C1s form a complex located between the C1q strands
2
When viewed by electron microscopy, what does C1q look like?
6-stranded whip
What is C1 activated by?
Ab-Ag complexes
C1q is activated when its strands bind to activating sites on _________ antibody molecules
Clustered
What is C1s converted into?
Active protease
What antigen-bound single molecule can activate C1?
IgM
How can IgM molecule activate C1?
It’s pentameric
What antigen-bound molecule is the following:
Monomer
Paired, antigen molecules are necessary
IgG
What antigen-bound molecule is the following:
Polymer
IgM
What is less efficient than IgM at activating the classical pathway?
IgG
What cannot act on soluble C2, and the C2 must first be bound to C4b before it can be cleaved?
C1s
