Heavy and light meromyosin are components of

Options

A. Actin filament
B. Myosin filament
C. Troponin protein
D. Tropomyosin protein

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the components of heavy and light meromyosin. To answer this, we need to identify where these components are found.

2. **Identifying the Context**: Heavy and light meromyosin are associated with muscle proteins. Specifically, they are parts of the myosin protein, which is crucial for muscle contraction.

3. **Structure of Myosin**: Myosin is a thick filament protein in muscle fibers. It is composed of two main parts: heavy meromyosin (HMM) and light meromyosin (LMM).

4. **Defining Heavy and Light Meromyosin**:
- **Heavy Meromyosin (HMM)**: This part contains the globular head of the myosin molecule and a short arm. The globular head has an active site for ATP binding and interacts with actin during muscle contraction.
- **Light Meromyosin (LMM)**: This part extends from the heavy meromyosin and forms the tail of the myosin molecule.

5. **Function in Muscle Contraction**: The interaction between actin (thin filament) and myosin (thick filament) is essential for muscle contraction. The heavy meromyosin acts as an ATPase enzyme, facilitating the energy transfer necessary for muscle movement.

6. **Conclusion**: Based on the structure and function of myosin, we conclude that heavy and light meromyosin are components of the myosin protein found in muscle fibers.

7. **Final Answer**: The correct answer is that heavy and light meromyosin are components of **myosin protein in muscle fibers**.

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