Question 55:
Warfarin has which of the following functions?
The correct answer is (A) Blood anticoagulant.
Warfarin functions as a blood anticoagulant by inhibiting vitamin K epoxide reductase (VKORC1), which blocks the recycling of vitamin K needed for carboxylation of clotting factors II, VII, IX, and X, thereby reducing blood clotting.
Option Breakdown
(A) Blood anticoagulant
Warfarin prevents thrombus formation in conditions like atrial fibrillation, DVT, and post-MI by depleting active vitamin K, creating an antithrombotic state monitored via INR (target 2-3).
(B) Mitochondrial electron carrier
This describes components of the electron transport chain like ubiquinone (coenzyme Q) or cytochromes, unrelated to Warfarin’s vitamin K antagonism.
(C) Antioxidant
Antioxidants like tocopherol (Vitamin E) or ascorbic acid neutralize free radicals; Warfarin lacks this activity and may increase bleeding risk.
(D) A sugar carrier
Sugar carriers refer to transporters like GLUT proteins for glucose uptake, not Warfarin’s coagulation effects.
Introduction to Warfarin Blood Anticoagulant
Warfarin blood anticoagulant action prevents clots via vitamin K-dependent factor inhibition, essential knowledge for GATE Life Sciences pharmacology and biochemistry sections.
Mechanism of Warfarin Anticoagulation
Warfarin competitively inhibits VKORC1, halting vitamin K regeneration for factors II/VII/IX/X gamma-carboxylation, with initial hypercoagulability from rapid protein C/S depletion overcome by sustained effects.
Therapeutic INR monitoring (2.0-3.0) balances efficacy against hemorrhage risk.
Functions Comparison Table
| Option | Primary Role | Warfarin Match? | Mechanism Example |
|---|---|---|---|
| Blood Anticoagulant | Inhibits clotting factors | Yes | VKORC1 inhibition |
| Mitochondrial Electron Carrier | ETC redox | No | Ubiquinone |
| Antioxidant | Free radical scavenging | No | Vitamin E |
| Sugar Carrier | Glucose transport | No | GLUT transporters |
Confirms warfarin blood anticoagulant precisely.
Relevance for Life Sciences Students
Links to prior liver questions (albumin synthesis site, acute failure risks) and vitamin D3 activation; Warfarin dosing adjusts for hepatic function in exams.
