COMPLEMENT | GUARANTEED SUCCESS STARTS
HERE! LEARN, PRACTICE & EXCEL!
What is a complement (system)? Answer: complement (system):
A part of the immune system that enhances the ability of antibodies and phagocytic cells
to clear microbes or damaged cells from the host.
what does the complement system include and do? Answer: The complement system
includes soluble and membrane-bound proteins that work together sequential manner
(cascade) to help destroy the pathogen.
Lysis, initiation of phagocytosis & directing to site of infection
What are the three types of complement activation pathways? Answer: three types of
complement activation pathways:
Three types:
1. Classic pathway
2. Alternative pathway
3. Lectin pathway
what are the three mechanisms of complement (activation pathways)? Answer: three
mechanisms of complement (activation pathways):
1. Inflammation
-Immune cell recruitment
2. Cytolysis
3. Opsonization and damage to nerve connections
- clearance
what are the similarities of all three types of complement activation pathways? Answer: -
All lead to pathogen destruction
- Although different, all connect at C3
What are the functions of the complement proteins?
APPHIA – Crafted with Care and Precision for Academic Excellence.
1
, a fragments? b fragments?
aka classical complement cascade Answer: functions of the complement proteins:
- to kill pathogens and infected cells (b fragments); always stays in pathway
- "a component" to cause different biological actions (a fragments) ; has biological
activities in solution ; always leaves the pathway
Types of complement activation pathways:
1. Classic Pathway
antibody?
components/factors?
stages? Answer: Types of complement activation pathways:
1. Classic Pathway
-antibody dependent
Components:
C1q, C1r, C1s, C4, C2
C3, C5 ,C6 ,C7 ,C8 ,C9
Stages:
recognition, activation, and formation of MAC and lysis
remember MAC --> Classic pathway
Recognition, Activation & Formation of Membrane attack complex: Answer: Recognition:
Fc portion of Ig interacts with C1
Activation:
Cleave C4, C2, C3 into a and b fragments
Formation of membrane attack complex:
C5,C6, C7, C8, C9 form the MAC
what is the method of activation of C1q? Answer: method of activation of C1q:
C1q starts the classical pathway. Binds to IgM or IgG.
What is C1q called? Answer: C1q is called the recognition unit for the classical pathway
What does the classical pathway begin with and how?
APPHIA – Crafted with Care and Precision for Academic Excellence.
2
HERE! LEARN, PRACTICE & EXCEL!
What is a complement (system)? Answer: complement (system):
A part of the immune system that enhances the ability of antibodies and phagocytic cells
to clear microbes or damaged cells from the host.
what does the complement system include and do? Answer: The complement system
includes soluble and membrane-bound proteins that work together sequential manner
(cascade) to help destroy the pathogen.
Lysis, initiation of phagocytosis & directing to site of infection
What are the three types of complement activation pathways? Answer: three types of
complement activation pathways:
Three types:
1. Classic pathway
2. Alternative pathway
3. Lectin pathway
what are the three mechanisms of complement (activation pathways)? Answer: three
mechanisms of complement (activation pathways):
1. Inflammation
-Immune cell recruitment
2. Cytolysis
3. Opsonization and damage to nerve connections
- clearance
what are the similarities of all three types of complement activation pathways? Answer: -
All lead to pathogen destruction
- Although different, all connect at C3
What are the functions of the complement proteins?
APPHIA – Crafted with Care and Precision for Academic Excellence.
1
, a fragments? b fragments?
aka classical complement cascade Answer: functions of the complement proteins:
- to kill pathogens and infected cells (b fragments); always stays in pathway
- "a component" to cause different biological actions (a fragments) ; has biological
activities in solution ; always leaves the pathway
Types of complement activation pathways:
1. Classic Pathway
antibody?
components/factors?
stages? Answer: Types of complement activation pathways:
1. Classic Pathway
-antibody dependent
Components:
C1q, C1r, C1s, C4, C2
C3, C5 ,C6 ,C7 ,C8 ,C9
Stages:
recognition, activation, and formation of MAC and lysis
remember MAC --> Classic pathway
Recognition, Activation & Formation of Membrane attack complex: Answer: Recognition:
Fc portion of Ig interacts with C1
Activation:
Cleave C4, C2, C3 into a and b fragments
Formation of membrane attack complex:
C5,C6, C7, C8, C9 form the MAC
what is the method of activation of C1q? Answer: method of activation of C1q:
C1q starts the classical pathway. Binds to IgM or IgG.
What is C1q called? Answer: C1q is called the recognition unit for the classical pathway
What does the classical pathway begin with and how?
APPHIA – Crafted with Care and Precision for Academic Excellence.
2
