During fibrinolysis, which inactive protein is converted into the enzyme that breaks down fibrin?

1. Once a vessel heals, the clot must be removed to restore normal flow. 2. Fibrinolysis is that gradual degradation of the clot. 3. The inactive protein plasminogen is converted into active plasmin, which breaks down the fibrin. 4. Prothrombin and proaccelerin are clotting factors that build the clot rather than dismantle it. 5. Fibrinogen is the raw material of the clot mesh, so converting it would add to the clot rather than remove it. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 18 "The Cardiovascular System: Blood", section 18.5 Hemostasis_