Name the enzyme that catalyzes the reaction that converts fibrinogen to fibrin.Multiple ChoiceProthrombin activatorThrombinTissue thromboplastinPlasmin

Break Down the Problem

1. Identify the reaction being asked about: the conversion of fibrinogen to fibrin.
2. Determine which enzyme catalyzes this specific reaction.

Relevant Concepts

• Fibrinogen is a soluble plasma protein that is converted into fibrin, an insoluble protein, which is essential for blood clotting.
• The enzyme responsible for this conversion is key in the coagulation cascade.

Analysis and Detail

• The options provided are various substances involved in the blood coagulation process:
  1. Prothrombin activator: A complex involved in activating prothrombin to thrombin but does not act directly on fibrinogen.
  2. Thrombin: An enzyme that specifically converts fibrinogen into fibrin.
  3. Tissue thromboplastin: A term that usually refers to a mixture of lipoprotein factors involved in initiating blood clotting, but not the enzyme acting on fibrinogen.
  4. Plasmin: An enzyme that breaks down fibrin, involved in fibrinolysis, and not in the conversion from fibrinogen to fibrin.

Verify and Summarize

Among the provided options, thrombin is recognized as the specific enzyme that catalyzes the conversion of fibrinogen into fibrin, confirming its critical role in hemostasis.

Final Answer

Thrombin