Chapter 10 Regulatory Strategies 7 13 What is the final step in the clotting pathway? Ans:In the final step,fibrinogen,which contains six chains of three subunit types,is altered. Thrombin cleaves four of the chains,resulting in the formation of fibrin monomers. These monomers spontaneously assemble into the fibrin array.The clot is stabilized by cross-links between the amino acids catalyzed by transglutaminase. Section:10.4 14 What is the dual action of thrombin? Ans:Thrombin catalyzes the hydrolysis of fibrinogen to form active fibrin.But it also has a role in shutting down the cascade by regulating protein C,a protease that digests other clotting enzymes Va and VIlIa. Section:10.4 15 Individuals in a royal family suffered from hemophilia and often died early from bleeding.What is the cause of this disease?How is it treated? Ans:The disease in the royal family was caused by faulty factor VIII of the intrinsic pathway. It is treated by the addition of supplemental protein,originally isolated from serum,but now a recombinant product. Section:10.4 and Figure 10.26Chapter 10 Regulatory Strategies 7 13 What is the final step in the clotting pathway? Ans: In the final step, fibrinogen, which contains six chains of three subunit types, is altered. Thrombin cleaves four of the chains, resulting in the formation of fibrin monomers. These monomers spontaneously assemble into the fibrin array. The clot is stabilized by cross-links between the amino acids catalyzed by transglutaminase. Section: 10.4 14 What is the dual action of thrombin? Ans: Thrombin catalyzes the hydrolysis of fibrinogen to form active fibrin. But it also has a role in shutting down the cascade by regulating protein C, a protease that digests other clotting enzymes Va and VIIIa. Section: 10.4 15 Individuals in a royal family suffered from hemophilia and often died early from bleeding. What is the cause of this disease? How is it treated? Ans: The disease in the royal family was caused by faulty factor VIII of the intrinsic pathway. It is treated by the addition of supplemental protein, originally isolated from serum, but now a recombinant product. Section: 10.4 and Figure 10.26