The Complement System

Question 1

What is the primary function of the complement system?

Answer 1

To enhance the ability of antibodies and phagocytic cells to clear pathogens.

Question 2

True or False: The complement system is part of the adaptive immune response.

Answer 2

False

Question 3

What are the two main pathways that activate the complement system?

Answer 3

Classical pathway and alternative pathway.

Question 4

Fill in the blank: The complement component C3 is crucial for the ________ of the complement system.

Answer 4

activation

Question 5

What triggers the classical pathway of complement activation?

Answer 5

The binding of antibodies to antigens.

Question 6

Which complement component is cleaved into C3a and C3b during activation?

Answer 6

C3

Question 7

Multiple choice: Which of the following is NOT a function of C3b?

Answer 7

Inhibiting phagocytosis

Question 8

What is the role of C3a in the complement system?

Answer 8

To act as an anaphylatoxin, promoting inflammation.

Question 9

True or False: The alternative pathway is antibody-dependent.

Answer 9

False

Question 10

What is the initial step in the alternative pathway of complement activation?

Answer 10

Spontaneous hydrolysis of C3.

Question 11

Fill in the blank: The alternative pathway is continuously ________ at low levels.

Answer 11

activated

Question 12

Which component stabilizes the C3 convertase in the alternative pathway?

Answer 12

Properdin

Question 13

What is the end result of both the classical and alternative pathways?

Answer 13

Formation of the C3 convertase.

Question 14

Multiple choice: Which of the following complement proteins is involved in opsonization?

Answer 14

C3b

Question 15

True or False: The complement system can lyse pathogens directly.

Answer 15

True

Question 16

What is the common pathway that follows both the classical and alternative pathways?

Answer 16

The terminal pathway leading to the formation of the membrane attack complex (MAC).

Question 17

Which complement proteins form the membrane attack complex (MAC)?

Answer 17

C5b, C6, C7, C8, and C9.

Question 18

Fill in the blank: The complement system helps in the clearance of ________ from the body.

Answer 18

immune complexes

Question 19

What is the function of complement regulatory proteins?

Answer 19

To prevent damage to host cells by regulating complement activation.

Question 20

Multiple choice: Which complement component is primarily involved in inflammation?

Answer 20

C3a

Question 21

True or False: The classical pathway can only be activated by IgM antibodies.

Answer 21

False

Question 22

What is the role of C5 convertase in the complement system?

Answer 22

To cleave C5 into C5a and C5b.

Question 23

Fill in the blank: The complement system is a part of the ________ immune system.

Answer 23

innate

Question 24

Which complement pathway is activated by pathogens without the need for antibodies?

Answer 24

Alternative pathway.

Question 25

What is the significance of the complement system in the immune response?

Answer 25

It enhances opsonization, inflammation, and pathogen lysis.

Question 26

What is opsonization?

Answer 26

Opsonization is the process by which pathogens are marked for ingestion and destruction by phagocytes.

Question 27

True or False: Opsonization enhances the ability of the immune system to identify and eliminate pathogens.

Answer 27

True

Question 28

Fill in the blank: Opsonization involves the binding of ________ proteins to the surface of pathogens.

Answer 28

opsonin

Question 29

Which of the following is an example of an opsonin? A) Antibodies B) Hormones C) Enzymes

Answer 29

A) Antibodies

Question 30

What role do phagocytes play in opsonization?

Answer 30

Phagocytes recognize and engulf opsonized pathogens, leading to their destruction.