IMMUNOLOGY KUBY CHAPTER 6 THE
COMPLEMENT SYSTEM EXAM REVIEW
QUESTIONS WITH COMPLETE
SOLUTIONS
1. Which of the following refers to the complex that provides the enzymatic activity in the
alternative pathway C3 convertase? - ANSWER -C3̅b̅ B̅b̅
2. Which of the following is TRUE about the C5 convertase? - ANSWER -All of the
above (C5 convertase can consist of the membrane-bound components C3b2Bb; C5
convertase cleaves C5 into C5a and C5b, with the b chain attached to the pathogen
surface and the a chain dissociating away to serve as a potent proinflammatory
chemotactic factor; C5 convertase is an important player in the production of the MAC.)
3. Which of the following BEST explains the timing of the classical pathway of
complement fixation, relative to the other pathways of complement fixation, against a
pathogen in an individual who has never been exposed to said pathogen? - ANSWER -
No target for C1qrs exists on the surface of the pathogen in the earliest stages of the
response to it.
4. Which of the following complement fixation pathways can be initiated by a soluble C3
convertase? - ANSWER -Alternative
5. Which of the following provides serine protease activity in the classical complement
activation pathway? - ANSWER -Both B and C (C1r & C1s)
6. Which of the following is the MOST potent anaphylatoxin produced during the
complement cascade? - ANSWER -C5a
7. To which of the following is MBL most structurally similar? - ANSWER -C1q
8. Which of the following binds to surface-bound C3b during formation of the alternative
C3 convertase? - ANSWER -Factor B
9. Which of the following can be directly activated as a soluble protein in the
microenvironment surrounding a pathogenic cell? - ANSWER -C3
10. Which of the following acts as a protease that is required to generate the alternative
pathway C3 convertase? - ANSWER -Factor D
COMPLEMENT SYSTEM EXAM REVIEW
QUESTIONS WITH COMPLETE
SOLUTIONS
1. Which of the following refers to the complex that provides the enzymatic activity in the
alternative pathway C3 convertase? - ANSWER -C3̅b̅ B̅b̅
2. Which of the following is TRUE about the C5 convertase? - ANSWER -All of the
above (C5 convertase can consist of the membrane-bound components C3b2Bb; C5
convertase cleaves C5 into C5a and C5b, with the b chain attached to the pathogen
surface and the a chain dissociating away to serve as a potent proinflammatory
chemotactic factor; C5 convertase is an important player in the production of the MAC.)
3. Which of the following BEST explains the timing of the classical pathway of
complement fixation, relative to the other pathways of complement fixation, against a
pathogen in an individual who has never been exposed to said pathogen? - ANSWER -
No target for C1qrs exists on the surface of the pathogen in the earliest stages of the
response to it.
4. Which of the following complement fixation pathways can be initiated by a soluble C3
convertase? - ANSWER -Alternative
5. Which of the following provides serine protease activity in the classical complement
activation pathway? - ANSWER -Both B and C (C1r & C1s)
6. Which of the following is the MOST potent anaphylatoxin produced during the
complement cascade? - ANSWER -C5a
7. To which of the following is MBL most structurally similar? - ANSWER -C1q
8. Which of the following binds to surface-bound C3b during formation of the alternative
C3 convertase? - ANSWER -Factor B
9. Which of the following can be directly activated as a soluble protein in the
microenvironment surrounding a pathogenic cell? - ANSWER -C3
10. Which of the following acts as a protease that is required to generate the alternative
pathway C3 convertase? - ANSWER -Factor D
