Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biochem exam 3 > Complement System > Flashcards

Complement System Flashcards

(58 cards)

Start Studying
1
Q

What is innate immunity?

A

non-specific immune response
-genetically determined
-include mucous secretion, complement proteins, and certain white blood cells (neutrophils & macrophages)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is adaptive immunity?

A

specific to antigen/pathogen
-contain lymphocytes and small number of genetically encoded proteins that are able recognize and deactivate specific antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the two main functions of the complement system?

A

membrane perturbation and inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is oponsization?

A

it is a part of membrane perturbation
-coats the membrane of pathogens to promote the removal of pathogens
-also leads to the assembly of the membrane attack complex on pathogen membrane that will lead to lysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does the complement system enhance inflammatory response?

A

release anaphylatoxins that promote cell activation or migration to an inflammatory site (chemotaxis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

When is the complement system activated?

A

in innate immunity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the three ways the complement system can be activated?

A

C3 turnover, natural Abs, and lectins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does C3 turnover do?

A

engage the alternative pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What do Natural Abs do?

A

engage the classical pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What do lectins do?

A

bind to carbohydrates on target and engages the lectin pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What replaces natural Abs in adaptive immunity?

A

specific Abs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What three immune functions are triggered by the complement system?

A

-phagocytosis
-inflammation
-membrane attack

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What has the most important opsonizing activity in phagocytosis?

A

C3b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the chemotactically attracting neutrophils and macrophages in inflammation?

A

anaphylatoxins C3a and C5a

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is inflammation?

A

local response to cellular injury that is marked by capillary dilation, leukocytic infiltration, redness, heat, and pain
-serves to eliminate damaged tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the wheal and flare response?

A

reaction that occurs during type 1 allergic reactions
-swelling produced by release of serum into the tissues (wheal) and redness of skin, resulting from dilation of blood vessels (flare)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What triggers the classical pathway?

A

activation of C1-complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the mannose-binding lectin pathway?

A

homologous to the classical pathway
-uses the opposins: mannose binding lectin and ficolin (NOT C1q)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does the alternative pathway differ from other pathways?

A

does not rely on pathogen-binding antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

is the alternative pathway always activated?

A

yes- at a low level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the central component of the complement system?

A

complement fixation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is complement fixation?

A

C3 cleaved into C3a and C3b
C3b tags bacteria for destruction
C3a recruits phagocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the three major components of the classical pathway?
(this is hard to word)

A

C1, C2, and C4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What ion is the classical pathway dependent on?

25
What is the C1 complex?
complex of C1q, C1r, and C1s -heads can bind to constant regions of immunoglobulin molecules or directly to the pathogen surface -cause conformational change in C1r which cleaves and activates C1s
26
Steps of the classical pathway:
-activated C1 cleaves C4 to C4a and C4b, which binds to microbial surface -C4b binds C2, which is cleaved by C1 to C2a and C2b, forming C4b2a -C4b2a is a C3 convertase that cleaves C3 to C3a and C3b, which binds to microbial surface or the convertase surface
27
How many C3 molecules can one C4b2a cleave?
up to 1000 *amplification effect
28
What are all three pathways (classical, mannose binding, and alternative) dependent on?
C3 convertase
29
What are the two serine proteases associated with mannan-binding lectin complex?
MASP-1 and 2
30
Who is the hottest in the friend group?
Haley
31
Who is the silliest little goose in the friend group?
Trick question... Alli and Molly
32
Who always skips class?
Dom and Adam
33
Who are the two best roomies ever?
Grace and Gracie
34
When the mannan-binding lectin binds to bacterial surfaces, what happens?
the serine proteases become activated and then activate the complement system -cleaves C4 and C2
35
What is C4b2a?
C3 convertase
36
What four proteins are involved in the alternative pathway of the complement system?
C3, factor B, factor D, and properdin
37
What are the steps of the alternative pathway?
-C3b deposited by classical or lectin pathway C3 convertase -C3b binds to factor B -bound factor B is cleaved by plasma protease factor D into Ba and Bb -C3bBb complex is C3 convertase, cleaving many C3 molecules to C3a and C3b
38
What triggers the alternative pathway?
covalent binding of C3b to pathogen or cell surface
39
What is Factor B cleaved into?
Ba and active protease Bb
40
what are the terminal complement components that form the membrane attack complex?
C5b, C6, C7, C8, C9
41
What is the C3 convertase of the alternative pathway?
C3bBb
42
What are the steps of the membrane attack complex?
-C5b binds to C6 and C7 -C5b67 complex binds to membrane via C7 -C8 binds to the complex and inserts into the cell membrane -C9 molecules bind to the complex and polymerize -10-16 molecules of C9 bind to and form a pore in the membrane *need to know: there are pre-made proteins (C9) that allow you to make a pore in cells*
43
What does activation of complement cause on the surface of the microorganism?
deposition of C3b
44
What binds to C3b to start the process of phagocytosis?
CR1 receptor on phagocytes
45
if just C3b is bound to CR1 receptor, does phagocytosis occur?
no *C3b is regulated on whether it will cause phagocytosis or not
46
What causes the activation of the phagocytes?
binding to C5a
47
What helps to regulate complement activation?
series of proteins that help to protect the host cell from accidental damage
48
what does CD59 do?
prevents formation of membrane-attack complex on autologous or allogenic cells
49
What helps to block the creation of excess C3 convertase and C3b?
DAF -blocks the association of Factor B with C3b as well as accelerating dissociation of Bb from C3b
50
what does DAF do?
stops formation of new C3b
51
Is disrupting the complement system okay?
no, it can cause many different disease
52
What is paroxysmal nocturnal hemoglobinurina?
acquired disorder that results in premature death and impair production of blood cells -RBC, leukocytes, and platelets -affects both sexes equally -deficiency in DAF protein
53
What is a treatment for paroxysmal nocturnal hemoglobinurina?
therapeutic inhibition of C5 Eculizumab -humanized recombinant murine monoclonal antibody -antibody binds to C5 near the cleavage site and prevents its cleavage into C5b and C5a
54
What is atypical hemolytic uremic syndrome?
-chronic uncontrolled activation of complement system -multiple blood clots form throughout the body -mutation in Factor H, Factor I, or membrane cofactor protein
55
What is hereditary angioedema?
-recurrent attacks of severe swelling -3 types
56
What causes type I hereditary angioedema?
mutation in gene that makes C1 inhibitor protein -deficiency in C1
57
What causes type II hereditary angioedema?
mutation in gene that makes C1 inhibitor protein -atypical C1 protein that is less capable to suppressing activation of complement system
58
What causes type III hereditary angioedema?
often due to mutation in Factor XII gene

Biochem exam 3 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions