Final answer:
The enzyme responsible for the conversion of fibrinogen to fibrin during blood clotting is thrombin, which is central to the activation of the common pathway in the coagulation process.
Step-by-step explanation:
The enzyme that converts fibrinogen to fibrin is thrombin. The conversion of fibrinogen to fibrin is an essential part of blood clot formation, particularly during the activation of the common pathway in hemostasis. When factor Xa is activated by either the intrinsic or extrinsic pathways, it, in conjunction with factor V, Ca2+, and phospholipids, forms the prothrombinase complex, which then converts prothrombin (factor II) into active thrombin.