Immunity: Chapter 03, Innate Immunity

Cleavage of complement components by proteases associated with C1q, MBL or ficolins play an important part in the initiation of the complement cascade. Which of the following complement components are cleaved by these proteases?

	a)	C2
	b)	C3
	c)	C4
	d)	factor B
	e)	factor H
CorrectWrong: a and c are correct.Your answer has been saved.

Which of the following statements are true?

	a)	The first step in the alternative pathway of complement activation is cleavage of C3 by factor D.
	b)	The large cleavage fragment of C4, C4b, contains a reactive thioester bond that can react with hydroxyl groups on carbohydrates.
	c)	C3b is both a component of a C3 convertase and a cleavage product of C3 convertase.
	d)	Amplification of the complement cascade occurs through activation of the early events in all three pathways of complement activation.
	e)	The complement cascade is confined to cell surfaces because reactive thioesters in the cleavage products C4b and C3b form covalent bonds with cell surfaces.
	f)	The complement cascade is confined to cell surfaces because active products of C3 cannot be generated in solution.
	g)	The complement cascade is confined to cell surfaces because C3 convertases are formed only when the two components that compose them are bound to membranes.
	h)	The complement cascade is confined to cell surfaces because active products of C3 are rapidly bound by factor H in solution and subsequently degraded.
CorrectWrong: b, c, e and h are true.Your answer has been saved.