The correct structure and regulatory proteins of muscles are

Options

A. `{:("Structural" ,"Regulatory"),("Troponin","Tropomysin"):}`
B. `{:("Structural" ,"Regulatory"),("Troponin","Actin"):}`
C. `{:("Structural" ,"Regulatory"),("Tropomyosin","Actin"):}`
D. `{:("Structural" ,"Regulatory"),("Actin","Troponin"):}`

Answer

To answer the question about the correct structure and regulatory proteins of muscles, we can break it down into two main categories: structural proteins and regulatory proteins.

### Step-by-Step Solution:

1. **Identify Structural Proteins**:
- The primary structural proteins in muscle tissue are **actin** and **myosin**.
- Actin is a thin filament, while myosin is a thick filament. Together, they are responsible for muscle contraction and movement.

2. **Identify Regulatory Proteins**:
- The regulatory proteins that control the interaction between actin and myosin are **troponin** and **tropomyosin**.
- Troponin binds to calcium ions and causes a conformational change that moves tropomyosin away from the actin binding sites, allowing myosin to bind to actin and initiate contraction.

3. **Function of Structural Proteins**:
- Actin and myosin work together to facilitate muscle contraction and relaxation. The sliding filament theory explains how these proteins interact during muscle contraction.

4. **Function of Regulatory Proteins**:
- Troponin and tropomyosin regulate the contraction process. When calcium ions are released into the muscle cell, they bind to troponin, which then causes tropomyosin to shift, exposing the binding sites on actin for myosin.

5. **Conclusion**:
- The correct structure and regulatory proteins of muscles are:
- **Structural Proteins**: Actin and Myosin
- **Regulatory Proteins**: Troponin and Tropomyosin

### Final Answer:
- **Structural Proteins**: Actin and Myosin
- **Regulatory Proteins**: Troponin and Tropomyosin

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