Which two clotting proteins are found in the plasma?

The presence of fibrinogen and prothrombin in plasma is crucial to the blood clotting process. Fibrinogen is a soluble plasma protein that is converted into fibrin during the clotting process, which forms a mesh that contributes to the structure of a blood clot. Prothrombin is a precursor to thrombin, an enzyme that plays a key role in converting fibrinogen to fibrin and is essential for the coagulation cascade. Both proteins are critical for hemostasis, the process that prevents and stops bleeding.

In contrast, albumin and globulin serve important functions in the body, such as maintaining osmotic pressure and transporting substances, but they are not primarily involved in the clotting process. Hemoglobin is primarily responsible for oxygen transport in red blood cells, while thrombin, although involved in coagulation, is not found in its inactive form (like prothrombin) in plasma. Antithrombin is a protein that helps regulate blood clotting by inhibiting thrombin and other clotting factors, but it is not a direct participant in the formation of the clotting matrix like fibrinogen and prothrombin. Fibrillin is related to connective tissue structures and does not play a role