Answer. Calcium ion (C++) Calcium ions are essential in all three stages of coagulation-- Stage 1, Stage 2 and Stage 3.
Work Step by Step
Calcium is necessary in the Stage One (Stage I) processes that end with the formation of prothrombin activator. In Stage Two the end process is the conversion of prothrombin to thrombin through the action of prothrombin activator. Calcium ions are involved in one of the steps in these reactions. In stage Three, thrombin and Ca++ ions act on fibrin stabilization factor (FSF, factor XII) to covert fibrin polymers into a fibrin mesh. The formation of this fibrin network is a vital process in the formation of clots. Coagulation is an essential life saving process that occurs in approximately four minutes after injury. Calcium ions are essential for this process to happen fast enough to stanch a potential life-threatening loss of blood after an injury.