prothrombin
pro throm bin |prōˈTHrämbən proʊˈθrɑmbən | ▶noun Biochemistry a protein present in blood plasma that is converted into active thrombin during coagulation.
prothrombin |prəʊˈθrɒmbɪn | ▶noun [ mass noun ] Biochemistry a protein present in blood plasma which is converted into active thrombin during coagulation.