Prothrombinase is a key enzyme involved in the blood clotting process. The enzyme is secreted by cells in the liver and is responsible for converting prothrombin into thrombin, a key component in blood clotting. Although prothrombinase is a specific term for this enzyme, there are several other synonyms that can be used to describe it. Some of these include thrombokinase, factor Xa, and blood coagulation factor. These terms are often used interchangeably with prothrombinase in research studies and medical literature. Regardless of the synonym used, prothrombinase is critical for maintaining healthy blood clotting, and abnormalities in its function can lead to serious health complications.