Extension of Ppt 6 Complement

Question 1

What is C3b used for?

Answer 1

opsonization of microbes

Question 2

who recognizes C3b in phagocytes?

Answer 2

C1 receptor

Question 3

What other complement molecule is recognized with C1 receptor in phagocytes?

Answer 3

C4b

Question 4

what other complement molecule works as an opsonin?

Answer 4

C4b

Question 5

what does the MAC (membrane attack complex) do to microbes?

Answer 5

it creates pores in their membranes

Question 6

what are C3a, C4a and C5a?

Answer 6

anaphylatoxins

Question 7

what do anaphylatoxins do?

Answer 7

they cause smooth muscle contraction and histamine release from mast cells

Question 8

what complement pathway is activated by C3b?

Answer 8

the alternate pathway

Question 9

how do you start the classical pathway of complement? (binding what?)

Answer 9

you bind C1 to microbe

Question 10

what happens with complement if you bind a lectin to a microbe?

Answer 10

you start the Mannose binding lectin pathway

Question 11

what do all pathways have in common?

Answer 11

they all create the MAC complex and all lead to C3b

Question 12

what happens to C3 in plasma during the alternative pathway?

Answer 12

C3 gets hydrolized and forms C3b that binds to antigen

Question 13

In alternative pathway, fluid C3b will do what? by binding to whom?

Answer 13

bind to antigen, especially to Factor Bb

Question 14

When C3b binds to Factor Bb in the alternative pathway, what will be created?

Answer 14

C3 convertase

Question 15

what does the C3 convertase in alternative pathway do?

Answer 15

cleave more C3 to C3b

Question 16

In the alternative pathway, more C3b created will do what?

Answer 16

bind more and more to the microbe surface

Question 17

in the alternative pathway, when many C3b are bound to the Factor Bb, what is formed?

Answer 17

C5 convertase

Question 18

in the alternative pathway, what will C5 convertase do?

Answer 18

it will cleave C5 into C5b

Question 19

what does C5b initiate in the alternative pathway of complement?

Answer 19

it begins the late phase of complement

Question 20

how is the classical pathway of complement initiated?

Answer 20

by binding of C1 to the antibodies bound on microbe

Question 21

in the classical pathway of complement, what binds to the C1 protein? what happens after it binds?

Answer 21

C4 binds to C1 and C1 cleaves it to C4b

Question 22

In the classical pathway of complement, what will C4b do after it is cleaved by C1?

Answer 22

C4b will bind to microbe surface

Question 23

In the classical pathway of complement, what will happens after C4b binds to microbe and to the antibodies bound to microbe?

Answer 23

C2 binds to C4b and gets cleaved forming the complex C4b + C2a

Question 24

In the classical pathway of complement, what is another name for the complex C4b + C2a?

Answer 24

C3 convertase

Question 25

In the classical pathway of complement, what will the C4b + C2a complex do in the microbial surface?

Answer 25

it will cleave C3 into C3b

Question 26

In the classical pathway of complement, what will happen to the C3b produced by the C3 convertase (C4b+C2a complex)?

Answer 26

C3b binds to microbe surface and to the C3 convertase

Question 27

In the classical pathway of complement, when the C3b binds to C3 convertase, what gets formed?

Answer 27

the C5 convertase

Question 28

when does the late phase of compliment start?

Answer 28

when C5 convertase is formed

Question 29

what does the late phase involve?

Answer 29

cell lysis (MAC) and inflammation (C5a)

Question 30

what does DAF do to the alternate pathway of complement?

Answer 30

it removes the Factor Bb off the C3 convertase

Question 31

what does DAF do to the classical pathway of complement?

Answer 31

it will remove C4b off the C3 convertase

Question 32

what does the C1 inhibitor do?

Answer 32

blocks attachment of C1, so classical pathway of complement cant proceed

Question 33

What does C1R do in the alternate pathway of complement?

Answer 33

it removes Factor Bb preventing the formation of C3 convertase

Question 34

What does C1R do in the classical pathway of complement?

Answer 34

it removes C4b preventing formation of C3 convertase

Question 35

deficiency of C9 leads to profound infection by who?

Answer 35

Nisseria

Question 36

C2 and C4 deficiency leads to infections resembling what disease?

Answer 36

SLE

Question 37

what type of disease do C3 deficient ppl develop?

Answer 37

autoimmune