During contraction of muscles :-a)Actin Filament slide over actinb)Myosin filament slide over actinc)Actin filament slide over myosind)noneCorrect answer is option 'C'. Can you explain this answer?

Question

Answer

Mechanism of muscle contraction is best explained by the sliding filament theory, which states that contraction of a muscle fibre takes place by the sliding of the thin filaments over the thick filaments. The actin filament slide over myosin filament thus reduces the length of the sarcomere and contracts the muscle fibre.

So, the correct answer is option C.

Answer

Because according to sliding filament theory 'contraction of a muscle fibre takes place by the sliding of the thin filaments over the thick filaments'.Thus,actin filament slide over myosin filament thus reducing the length of the sarcomere and contracts the muscle fibre.

Answer

Sliding Filament Theory of Contraction
During muscle contraction the thin actin filaments slide over the thick myosin filament.
When Calcium is present the blocked active site of the actin clears.

Answer

Sliding Filament Theory:
Muscle contraction is driven by the sliding filament theory, where actin and myosin filaments slide past each other to shorten the muscle fiber.

Interaction of Actin and Myosin:
- During muscle contraction, the actin filaments slide over the myosin filaments.
- Myosin molecules have cross-bridges that attach to binding sites on actin filaments.
- The cross-bridges then pivot, pulling the actin filaments towards the center of the sarcomere, which shortens the muscle fiber.

Cross-Bridge Cycling:
- The process of actin filaments sliding over myosin filaments involves a series of steps known as cross-bridge cycling.
- This cycle includes attachment of myosin to actin, power stroke (movement of actin by myosin), and detachment of myosin from actin.

Role of Calcium:
- Calcium ions play a crucial role in muscle contraction by triggering the exposure of binding sites on actin filaments.
- When calcium levels increase in the muscle cell, it leads to the interaction between actin and myosin filaments.

Energy Requirement:
- Muscle contraction requires energy in the form of ATP (adenosine triphosphate).
- ATP is needed for the detachment of myosin from actin and resetting the myosin head for the next contraction cycle.

Conclusion:
In summary, during muscle contraction, the actin filaments slide over the myosin filaments due to the interaction between actin and myosin molecules. This process is driven by the cross-bridge cycling mechanism and requires the presence of calcium ions and ATP for the successful contraction of muscles.

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