Now as we see we have many examples of zymogen. So we have this is a zymogen, this is a zymogen, these are zymogens and so forth. Now the Zymogen that we actually studied very well is this zymogen here. So this is the xiaomogen that we're going to study. We're going to see how Thrombin a seren protease basically activates fibrinogen proteolytically into fiber and fibrin basically looks something like this. So let's discuss the process by which Thrombin actually activates fibrinogen.