Complement

What molecules gain protease activity once cut?

Zymogens

What are nucleophilically attacked to bind a molecule to the surface of a pathogen?

Thioester Bond

Which pathway is the first to be activated and is always happening?

Alternative

Which complement pathway will be activated last?

Classical

How can complement poke holes in the outer membrane?

Membrane Attack Complex (MAC)

Which complement molecule does all three pathways go through?

C3

What cleaves factor B?

Factor D

Where would you expect to find CR1?

On our cells

What binds to CR1?

C3b

What binds to CR2?

C3d

What is the C3 convertase of the alternative pathway?

C3bBb

What is a protein bound to the surface of a pathogen that facilitates its phagocytosis?

Opsonin

What is the C5 convertase of the alternative pathway?

C3b2Bb

What is the C5 convertase of the classical pathway?

C4b2a3b

Which stable anaphylatoxin recruits neutrophils to the site of infection?

C5a

Which complement component polymerizes to form the transmembrane pore in the MAC?

C9

What is the term for the molecules that contribute to acute inflammation by binding to receptors on mast cells, phagocytes, and endothelial cells?

Anaphylatoxins

What is the "gas pedal" protein that binds to the C3 convertase to protect it from inhibition by factor H?

Factor P

What is the "brake pedal" molecule that cleaves C3b to iC3b on a pathogen surface?

Factor I

What is the only molecule that when cleaved names the bigger fragment the "a" fragment and the smaller one the "b" fragment?

C2

What are the molecules that help negatively regulate complement on human cell serfaces?

DAF and MCP

Streptococcus pyogenes and Staphylococcus aureus recruit what molecule to help mimic human cells?

Factor H

What is the protease inhibitor that trap proteases with "bait"?

alpha2-macroglobulins

What molecule that can initiate the classical pathway is made of a pentamer of identical subunits?

C-reactive protein (CRP)

Besides CRP, what else can activate the classical pathway?

Antibodies

In the lectin pathway, what is the protease that cleaves C4 and C2?

MASP-2

In the classical pathway, what is the protease that cleaves C4 and C2?

C1s

What is the C3 convertase for the classical pathway?

C4b2a

In the classical pathway, what complement molecule would bind to the antibodies/CRP?

C1

Which molecule initiates the formation of the MAC?

C5b