The cation (mineral) necessary for coagulation of blood is

Options

A. Na
B. Ca
C. K
D. Cl

Answer

To answer the question about the cation (mineral) necessary for coagulation of blood, let's break down the process step by step:

### Step-by-Step Solution:

1. **Understanding Blood Coagulation**: Blood coagulation, also known as blood clotting, is a complex process that prevents excessive blood loss when an injury occurs. It involves the transformation of liquid blood into a gel-like substance, forming a clot.

2. **Role of Fibrin**: The primary component that forms the structure of a blood clot is fibrin. Fibrin is produced from fibrinogen, which is a soluble plasma protein.

3. **Activation of Fibrinogen**: The conversion of fibrinogen to fibrin is facilitated by an enzyme called thrombin. Thrombin is crucial for the clotting process.

4. **Formation of Thrombin**: Thrombin itself is generated from prothrombin, another plasma protein. The conversion of prothrombin to thrombin is triggered by an enzyme called thrombokinase.

5. **Role of Calcium Ions**: Calcium ions (Ca²⁺) play a vital role in the coagulation cascade. They are necessary for the activation of several clotting factors, including the conversion of prothrombin to thrombin.

6. **Conclusion**: Given the importance of calcium ions in the coagulation process, the cation (mineral) necessary for coagulation of blood is calcium.

### Final Answer:
The cation (mineral) necessary for coagulation of blood is **calcium**.

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