1. Fibrinogen is NOT an enzyme, it's a soluble glycoprotein. 2. The Factor VIIa/Tissue factor complex also activates factor IX which aids in amplification. 3. It's worth noting that factor Xa has some proteolytic ability similar to thrombin in activating small amounts of factor V - which will aid in forming the inital prothrombinase complexes. 4. It's also worth mentioning that factor VIII circulates in the blood as a complex with von Willebrand Factor. 5. The only zymogen thrombin (FII) activates is factor IX. The other two components activated by thrombin are factors V and VIII. Fibrin polymers and thrombin can activate and amplify the activity of FXIII once the monomers begin to spontaneously self assemble, which is achieved by crosslinking fibrin thus stabilising the plug. 6. You didnt explain the point of exposing the cleaved fibrinopeptide B site, only the attachment of cleaved FP-A to the gamma globular domain. 7. A hugely important part which you missed out is the activation of plasma protransglutaminase (FXIII) and the critical stabilising covalent crosslinking of the D-domains (the globular beta and gamma regions) of fibrin. There is some disagreement on how the covalent crosslinking actually occurs - whether longitudinally or transversely between the D-domains, but experimentation suggests the crosslinking is most likely transverse - a bonding that would confer greater elasticity on the fibrin.
I'm confused between this one and the video from 2014 called "Blood Clotting Cascade" since they seem to have minor differences...are they discussing the same thing? (P.S. Your videos are my saviour.... I started watching them in second year University when I was having trouble understanding my cell bio prof's explanations and they saved me in that class among many others since then...I'm now almost done my degree and hoping to go to vet school, so I'm thinking I will be watching these videos for a while still! No one else explains them as thoroughly and clearly as you and you are exactly how my brain needs it explained, so thank you!)
