Which enzyme converts soluble fibrinogen to insoluble fibrin?

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Multiple Choice

Which enzyme converts soluble fibrinogen to insoluble fibrin?

The enzyme doing this conversion is thrombin. It acts as a protease that cleaves fibrinopeptides A and B from soluble fibrinogen, turning it into fibrin monomers that then polymerize to form insoluble fibrin strands that mesh together to make a clot. Thrombin also activates Factor XIII to form XIIIa, which cross-links the fibrin network and stabilizes the clot. Plasmin digests fibrin during clot breakdown, not formation. Factor XIIIa stabilizes and cross-links fibrin but doesn’t convert fibrinogen to fibrin. Thromboplastin (tissue factor) starts the coagulation cascade that leads to thrombin production, but it isn’t the enzyme that directly converts fibrinogen to fibrin.

The enzyme doing this conversion is thrombin. It acts as a protease that cleaves fibrinopeptides A and B from soluble fibrinogen, turning it into fibrin monomers that then polymerize to form insoluble fibrin strands that mesh together to make a clot. Thrombin also activates Factor XIII to form XIIIa, which cross-links the fibrin network and stabilizes the clot.

Plasmin digests fibrin during clot breakdown, not formation. Factor XIIIa stabilizes and cross-links fibrin but doesn’t convert fibrinogen to fibrin. Thromboplastin (tissue factor) starts the coagulation cascade that leads to thrombin production, but it isn’t the enzyme that directly converts fibrinogen to fibrin.

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