L27 - Biochemistry of blood coagulation system Flashcards
Describe the molecular mechanism for activation of coagulation factors Recognize the importance of interaction between humoral and cellular factors in blood coagulation Contrast between intrinsic and extrinsic pathway Discover why blood coagulation is a rapid site specific and self limiting process
Name a factor which stimulates fibrin cross linking
Factor 13
Describe the structure of tissue factor
It is a transmembrane doman, with the part above the cytoplasm interacting with factor VII
Describe the role of extrinsic pathway in the coagulation
When there is endothelial damage, tissue factor is activated, factor VIIa binds to tissue factor to form Tissue Factor/ VIIa complexes -> activate factor X and IX -> Activate prothrombin -> cleavage of fibrinogen -> Fibrin
How can the binding between thrombin and antithrombin be increased
By the action of heparin
What is the cell that secret heparin
Endothelial cell
Describe the degradation of factor Va and VIIIa
Protein Kinase C is activated by thrombin attached to endothelial cells
Active protein kinase C inactivate factor Va and VIIIa
How is coagulation factor activated
Cleavage of peptide bond
Disulphide bond pulling the two cleaved molecules
