ATP-ase activity found in `:-`

Options

A. Myosin filament
B. Actin filament
C. Both
D. None

Answer

To answer the question about where ATPase activity is found, let's analyze the options provided step by step:

### Step 1: Understand ATPase Activity
ATPase is an enzyme that catalyzes the hydrolysis of ATP (adenosine triphosphate), releasing energy that is used for various cellular processes, including muscle contraction.

### Step 2: Identify the Options
The options given are:
1. Myosin filament
2. Actin filament
3. Both
4. None

### Step 3: Analyze Myosin Filament
- Myosin filaments are known to have ATPase activity. The myosin head contains an ATP-binding site and has ATPase activity that is crucial for muscle contraction.
- The ATPase activity is located approximately 5 nanometers away from the tip of the myosin head, and it is also 4 nanometers away from the actin binding site of myosin.

### Step 4: Analyze Actin Filament
- Actin filaments do not possess ATPase activity. Instead, they interact with myosin during muscle contraction, but they do not catalyze the hydrolysis of ATP.

### Step 5: Conclusion
Based on the analysis:
- Myosin filament has ATPase activity.
- Actin filament does not have ATPase activity.

Thus, the correct answer is **Myosin filament**.

### Final Answer
ATP-ase activity is found in **Myosin filament**.

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