Blood clotting encompasses sequence
of chemical whose respective
products enzymes that catalyze
following reactions (that why the
clotting are called cascade
). In the plasma
transforms into
thromboplastin, reaction triggered by
and platelet factors after
injury of blood vessel.

Thromboplastin catalyzes along
with ions the transformation
prothrombin into thrombin.
then catalyzesa reaction produces
fibrin from . Fibrin, as an
substance, precipitates to
a network that red blood cells
platelets forming the clot and
containing hemorrhage.