So this molecule is in its inactive form. This is the zymogen form of this molecule. Now what exactly does Thrombin actually do? So the entire goal of the extrinsic pathway and the intrinsic pathway is to basically amplify and activate this protein X, protein Ten. And the enzyme Ten basically combines with five to go on and form Thrombin from the Xymogen form prothrombin. Now Thrombin is actually a serine protease and it will activate this fibrinogen molecule pro Eelytically.