Which one of the following proteins is not the part of clotting mechanism of blood?

Options

A. Fibrinogen
B. thrombin
C. thromboplastin
D. globulin

Answer

To determine which protein is not part of the clotting mechanism of blood, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Clotting Mechanism**: The clotting mechanism involves a series of proteins that work together to stop bleeding when a blood vessel is injured. Key proteins involved include fibrinogen, thrombin, and thromboplastin.

2. **Identify Key Proteins**:
- **Fibrinogen**: This is a soluble plasma protein that is converted into fibrin during the clotting process.
- **Thrombin**: This is an active enzyme that converts fibrinogen into fibrin.
- **Thromboplastin**: This is a substance released from damaged tissues and platelets that initiates the clotting cascade.

3. **Consider the Options**: The question provides multiple options for proteins. We need to identify which one does not play a role in the clotting process.

4. **Analyze Each Option**:
- **Fibrinogen**: Part of the clotting mechanism.
- **Thrombin**: Part of the clotting mechanism.
- **Thromboplastin**: Part of the clotting mechanism.
- **Globulin**: Generally associated with immune functions, specifically as immunoglobulins, and is not directly involved in the clotting process.

5. **Conclusion**: Since fibrinogen, thrombin, and thromboplastin are all involved in the clotting mechanism, the protein that is not part of this mechanism is **globulin**.

### Final Answer:
**Globulin is not a part of the clotting mechanism of blood.**

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