Which one of the following proteins involved in the coagulation of blood?

Options

A. AN albumin
B. Serum amylase
C. A globulin
D. Fibrinogen

Answer

To determine which protein is involved in the coagulation of blood, we can analyze the options given: globulin, albumin, and fibrinogen.

### Step-by-Step Solution:

1. **Understanding Blood Proteins**:
- Blood contains several types of proteins, including albumin, globulin, and fibrinogen. Each of these proteins has specific functions.

2. **Role of Albumin**:
- Albumin is a protein that helps maintain the osmotic pressure of the blood. It prevents blood from leaking out of blood vessels but is not directly involved in blood coagulation.

3. **Role of Globulin**:
- Globulins are a group of proteins that include alpha, beta, and gamma globulins. They play roles in immune response and transport but do not directly participate in the coagulation process.

4. **Role of Fibrinogen**:
- Fibrinogen is a glycoprotein produced by the liver that is crucial for blood coagulation. When there is a blood vessel injury, fibrinogen is converted into fibrin, which forms a mesh that helps in the formation of blood clots.

5. **Conclusion**:
- Among the proteins listed, fibrinogen is the one specifically involved in the coagulation of blood. Therefore, the correct answer is fibrinogen.

### Final Answer:
- The protein involved in the coagulation of blood is **fibrinogen**.