Blood Clotting Flashcards
Factor I
Fibrinogen
Soluble plasma glycoprotein synthesized by liver
2 sets of alpha, beta, and gamma chains linked by disulfide bonds
Thrombin cleaves alpha and beta chains, releasing FpA & FpB, creating Fibrin
Factor II
Prothrombin
Zymogen precursor of thrombin symthesized in liver
Contains Gla residues that bind Ca
Inhibited by antithrombin (strongly potentiated by binding to Heparin)
Factor III
Membrane-bound glycoprotein found in sub-endothelial tissue, activated platelets, WBCs
Factor IV
Calcium ions
Factor V
Proaccelerin
Activated by IIa
Degraded by active proteinC/proteinS
Factor VII
Proconvertin
Contains Gla residues that bind calcium and membranes
Partially activated by binding to Factor III near negatively-charged membrane
Also activated by IIa
Inactivated by TPFI when Xa is present
Factor VIII
Anti-hemophilic Factor
Binds to and is stabilized by vWF
Complexes with IXa
Factor IX
Christmas Factor Serine protease zymogen synthesized in liver Contains Gla residues Activated by XIa and VIIa/III Inhibited by antithrombin
Factor X
Prothrombinase
Serine protease zymogen synthesized in liver
Contains Gla residues
Converted into active Xa by IXa/VIIIa and VIIa/III
Factor XI
Plasma thromboplastin Antecedent
Serine protease zymogen produced in liver
Converted to XIa by XIIa, IIa, and autocatalysis
Binds to HMWK
Factor XII
Hageman Factor
Partially activated by negatively-charged surfaces
Fully activated by kallikrein, autocatalysis
Factor XIII
Protransglutamidase
Composed of 2 a & 2 b chains
Activated by thrombin–>B chains dissociate
