Immunology 3 Exam; Questions & Answers
100% Correct
which complement activation pathway uses antibodies? Answer-classical
which complement activation pathway begins with a naive/immature C3? Answer-
alternative
which complement activation pathway involves innate immunity? Answer-alternative
what are the 2 substrates of the lectin complement pathway? Answer-MBL (mannose-
binding lectin) & CHO (usually mannose)
which complement pathway components play an important role in anaphylaxes & allergies?
Answer-C3a & C5a
(a ~ anaphylaxes/ allergies)
what is the end product of the complement pathway & what does it do? Answer-MAC; it
coats the pathogen for opsonization & introduces transmembrane channels --> lysis
what are the substrates of the classical complement pathway? Answer-Ab + Ag --> C1
complex (w/ serine protease)
what are the substrates of the alternative complement pathway? Answer-pathogen +
immature C3 (w/ thioester hydrolysis)
, Immunology 3 Exam; Questions & Answers
100% Correct
what is the MAC made up of? Answer-C5 through C9
what can inhibit C3 convertase? Answer-DAF
what is the complement system? Answer-a part of the immune system that enhances
(complements) the ability of antibodies & phagocytic cells to clear pathogens from an organism;
part of the innate immune system, but can also be recruited by the adaptive immune system
when stimulated, _______ in the complement system cleave specific proteins to release
_______ & initiate an amplifying cascade of further cleavages. The end result of this
complement activation/ complement fixation cascade is massive _______ of the response and
activation of the cell-killing _______ Answer-proteases; cytokines; amplification;
membrane attack complex
which antibodies start the classical complement pathway? Answer-IgM & IgG
at what step do the 3 different complement activation pathways converge? Answer-C3
convertase - where C3 & C5 proteins are being cleaved (activated)
the complement system is a series of ~20 heat labile ______ synthesized in the ______
Answer-plasma proteins; liver
, Immunology 3 Exam; Questions & Answers
100% Correct
complement functions in a cascade to attack extracellular pathogens; they do this via:
Answer-- lysing bacteria
- opsonizing bacteria
- promoting inflammation
TRUE/ FALSE: the complement cascade is highly regulated Answer-TRUE
TRUE/ FALSE: the complement cascade is highly specific Answer-FALSE - (highly
regulated; not specific)
TRUE/ FALSE: complement proteins are present in inactive forms in the serum Answer-
TRUE - (they're then triggered by 1 of the 3 mechanisms)
how are complement proteins triggered to enter the classical pathway? Answer-activated
by IgM or IgG binding to their surface
how are complement proteins triggered to enter the alternative pathway? Answer-
spontaneous activation in the blood or bacterial surfaces
how are complement proteins triggered to enter the lectin pathway? Answer-activated
by opsonins binding to bacterial cell surface
, Immunology 3 Exam; Questions & Answers
100% Correct
TRUE/ FALSE: when complement proteins are cleaved during activation, the larger fragment is
designated "a" & the smaller fragment is "b" Answer-FALSE - "a" is smaller, "b" is larger
in the classical pathway, which complement proteins are involved in the initial cascade?
Answer-C1 --> C4 --> C2 --> C3
in the classical pathway, which complement proteins are involved in the opsonin?
Answer-C3 --> C5 --> C6
in the classical pathway, which complement proteins are involved in the membrane attack
complex? Answer-C6 --> C7 --> C8 --> lots of C9
all pathways form a _______, which cleaves & activates ______ & ______; after this, the
pathways overlap & use the same proteins Answer-C3/C5 convertase; C3; C5
what is the end result of the classical pathway? Answer-peptide mediators of
inflammation, phagocyte recruitment
what is the end result of the alternative pathway? Answer-MAC, lysis of certain
pathogens & cells
100% Correct
which complement activation pathway uses antibodies? Answer-classical
which complement activation pathway begins with a naive/immature C3? Answer-
alternative
which complement activation pathway involves innate immunity? Answer-alternative
what are the 2 substrates of the lectin complement pathway? Answer-MBL (mannose-
binding lectin) & CHO (usually mannose)
which complement pathway components play an important role in anaphylaxes & allergies?
Answer-C3a & C5a
(a ~ anaphylaxes/ allergies)
what is the end product of the complement pathway & what does it do? Answer-MAC; it
coats the pathogen for opsonization & introduces transmembrane channels --> lysis
what are the substrates of the classical complement pathway? Answer-Ab + Ag --> C1
complex (w/ serine protease)
what are the substrates of the alternative complement pathway? Answer-pathogen +
immature C3 (w/ thioester hydrolysis)
, Immunology 3 Exam; Questions & Answers
100% Correct
what is the MAC made up of? Answer-C5 through C9
what can inhibit C3 convertase? Answer-DAF
what is the complement system? Answer-a part of the immune system that enhances
(complements) the ability of antibodies & phagocytic cells to clear pathogens from an organism;
part of the innate immune system, but can also be recruited by the adaptive immune system
when stimulated, _______ in the complement system cleave specific proteins to release
_______ & initiate an amplifying cascade of further cleavages. The end result of this
complement activation/ complement fixation cascade is massive _______ of the response and
activation of the cell-killing _______ Answer-proteases; cytokines; amplification;
membrane attack complex
which antibodies start the classical complement pathway? Answer-IgM & IgG
at what step do the 3 different complement activation pathways converge? Answer-C3
convertase - where C3 & C5 proteins are being cleaved (activated)
the complement system is a series of ~20 heat labile ______ synthesized in the ______
Answer-plasma proteins; liver
, Immunology 3 Exam; Questions & Answers
100% Correct
complement functions in a cascade to attack extracellular pathogens; they do this via:
Answer-- lysing bacteria
- opsonizing bacteria
- promoting inflammation
TRUE/ FALSE: the complement cascade is highly regulated Answer-TRUE
TRUE/ FALSE: the complement cascade is highly specific Answer-FALSE - (highly
regulated; not specific)
TRUE/ FALSE: complement proteins are present in inactive forms in the serum Answer-
TRUE - (they're then triggered by 1 of the 3 mechanisms)
how are complement proteins triggered to enter the classical pathway? Answer-activated
by IgM or IgG binding to their surface
how are complement proteins triggered to enter the alternative pathway? Answer-
spontaneous activation in the blood or bacterial surfaces
how are complement proteins triggered to enter the lectin pathway? Answer-activated
by opsonins binding to bacterial cell surface
, Immunology 3 Exam; Questions & Answers
100% Correct
TRUE/ FALSE: when complement proteins are cleaved during activation, the larger fragment is
designated "a" & the smaller fragment is "b" Answer-FALSE - "a" is smaller, "b" is larger
in the classical pathway, which complement proteins are involved in the initial cascade?
Answer-C1 --> C4 --> C2 --> C3
in the classical pathway, which complement proteins are involved in the opsonin?
Answer-C3 --> C5 --> C6
in the classical pathway, which complement proteins are involved in the membrane attack
complex? Answer-C6 --> C7 --> C8 --> lots of C9
all pathways form a _______, which cleaves & activates ______ & ______; after this, the
pathways overlap & use the same proteins Answer-C3/C5 convertase; C3; C5
what is the end result of the classical pathway? Answer-peptide mediators of
inflammation, phagocyte recruitment
what is the end result of the alternative pathway? Answer-MAC, lysis of certain
pathogens & cells
