Part A - Clotting Factors Clotting is necessary to mend breaks in circulatory vessels and to prevent extreme losses of blood, but it can also have detrimental effects if unregulated. Various factors may either enhance or inhibit this process. Sort the factors according to their effect on blood clotting.

- calcium ions
- heparin
- fibrinogen
- serum
- thrombin
- coumadin
- vitamin K
- PF3
- tissue factor
- aspirin

Clotting factors  

Explanation:

Clot enhancers: calcium ions, fibrinogen, thrombin, vitamin K, PF3, tissue factor

Calcium ions are required for the fibrin clot formation,also helps in the activation of thrombin from prothrombinFibrinogen is the substrate of thrombin and helps in the formation of a normal blood clot at the site of vascular disruptionThrombin converts fibrinogen into fibrin which leads to the formation of a fibrin clot;also causes platelet aggregation Vitamin K is the fat soluble vitamin which act as coenzyme,the aromatic ring of Vitamin K undergoes in sequential oxidation and reduction during the formation of active prothrombinPF3 comes into action whenever there is platelet activation,it is released and participates in thrombin formationTissue factor helps in the initiation of blood coagulation

Clot inhibitors: heparin, coumadin, aspirin

Heparin is an anticoagulant which prevents the formation of blood clot,used before surgeries to minimize the risk of blood clotsCoumadin is also known as Warfarin which is a synthetic compound that inhibits the formation of active prothrombin and cause death of organisms due to constitutive bleedingAspirin is a blood clot inhibitor and helps in preventing cardiovascular events in high risk patients

Serum is called blood plasma without fibrinogens and does not play any role in blood clotting(neither as an enhancer nor as an inhibitor)

This is the most closely resembles the model.