Globular head of myosin contains

Options

A. Ca ions in large quantities
B. Troponin
C. ATPase enzyme
D. ATP.

Answer

**Step-by-Step Solution:**

1. **Understanding Myosin**: Myosin is a contractile protein primarily found in muscle tissue. It plays a crucial role in muscle contraction.

2. **Structure of Myosin**: Myosin has a long tail and a globular head. The globular head is essential for its function in muscle contraction.

3. **Function of the Globular Head**: The globular head of myosin interacts with actin filaments during muscle contraction. It is responsible for the hydrolysis of ATP, which provides the energy needed for muscle contraction.

4. **Components of the Globular Head**: The globular head contains an active site for ATPase, which is an enzyme that catalyzes the breakdown of ATP (adenosine triphosphate).

5. **Role of Calcium and Magnesium Ions**: In addition to the ATPase enzyme, the globular head also interacts with calcium ions and magnesium ions. These ions are important for the proper functioning of the ATPase enzyme and for muscle contraction.

6. **ATP Hydrolysis**: During muscle contraction, the ATPase enzyme in the globular head catalyzes the breakdown of ATP into ADP (adenosine diphosphate) and inorganic phosphate. This reaction releases energy that is used for muscle contraction.

7. **Conclusion**: Therefore, the globular head of myosin contains the ATPase enzyme, which is essential for muscle contraction.

**Final Answer**: The globular head of myosin contains ATPase enzyme.

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