ATP-ase activity found in :-a)Myosin filamentb)Actin filamentc)Bothd)NoneCorrect answer is option 'A'. Can you explain this answer?

Question

Answer

In all myosins, the head domain is a specialized ATPase that is able to couple the hydrolysis of ATP with motion. A critical feature of the myosin ATPase activity is that it is actin-activated. In the absence of actin, solutions of myosin slowly convertATP into ADP and phosphate.

Answer

Right option is A because P-ATP ase ,P-ATPases ( sometimes known as E1-E2ATPAses) are found in bacteria and also in eukaryotic plasma membranes and organelles ,its name is due to shot time attachment of inorganic phosphate at the aspartate residues at the time of activation

Answer

ATP-ase activity found in myosin filament:
Myosin filament is a protein found in muscle cells that is responsible for muscle contraction. It is a motor protein that converts chemical energy in the form of ATP (adenosine triphosphate) into mechanical work. The ATP-ase activity refers to the ability of an enzyme to hydrolyze ATP, releasing energy in the process.

Explanation:
The ATP-ase activity found in myosin filaments is crucial for muscle contraction. Here's how it works:

1. Binding of ATP: Myosin binds to ATP, causing it to undergo a conformational change. This conformational change allows myosin to detach from actin, which is a thin filament.

2. Hydrolysis of ATP: Myosin hydrolyzes ATP into ADP (adenosine diphosphate) and inorganic phosphate (Pi). This hydrolysis releases energy, which is stored in the myosin head.

3. Cross-bridge formation: The energy released from ATP hydrolysis causes the myosin head to rotate and attach to actin, forming a cross-bridge.

4. Power stroke: When the myosin head attaches to actin, it undergoes a power stroke, during which it changes its conformation and pulls the actin filament towards the center of the sarcomere (the basic unit of muscle contraction).

5. Release of inorganic phosphate: After the power stroke, the myosin head releases the inorganic phosphate (Pi) that was produced during ATP hydrolysis.

6. Release of ADP: Finally, the myosin head releases ADP, allowing it to bind to another ATP molecule, leading to the detachment of myosin from actin and the initiation of another cycle of contraction.

Conclusion:
In summary, the ATP-ase activity found in myosin filaments is essential for muscle contraction. It allows myosin to bind and hydrolyze ATP, releasing energy that is used to generate force and cause muscle contraction. Without this ATP-ase activity, the myosin filaments would not be able to perform their role in muscle contraction.

Answer

Myosin has active ATP binding sites where a molecule of ATP is hydrolysed for every cross bridge formation between an actin and myosin filament.

Answer

In all myosins, the head domain is a specialized ATP-ase that is able to couple the hydrolysis of ATP with motion. A critical feature of the myosin ATP-ase activity is that it is actin-activated. In the absence of actin, solutions of myosin slowly convert ATP into ADP and phosphate.

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