Thrombin then turns factor I or fibrinogen, which is soluble, into factor Ia or fibrin, which is insoluble and precipitates out of the blood at the site of injury.
Others run defense for you, like the gamma globulin antibodies that are released by plasma cells during an immune response, or fibrinogen proteins, which are vital to forming blood clots and stopping bleeding.
Plasma is the liquid part of the blood and consists of water, dissolved proteins, sugar, salts, hormones, and other substances. The four major plasma proteins are albumin, globulin, fibrinogen, and prothrombin.