Question

Explain the steps of crossbridge cycling that lead to force production? Include the ferms: motor unit, calcium, actin, myosin, and force production

Answer 1

Crossbridge cycling involves several steps, including calcium release, cross-bridge formation, power stroke, and ATP hydrolysis. These steps lead to muscle contraction and force production.

Step-by-step explanation:

In crossbridge cycling, the motor unit, calcium, actin, myosin, and force production work together to produce muscle contraction. Here are the steps involved:

1. When a motor neuron stimulates a muscle fiber, calcium is released from the sarcoplasmic reticulum into the cytoplasm.
2. Calcium binds to the troponin on the actin filament, causing tropomyosin to move away from the myosin binding sites on actin.
3. Once the myosin binding sites are exposed, the myosin heads bind to the actin filament, forming cross-bridges.
4. The myosin heads undergo a power stroke, moving the actin filament towards the center of the sarcomere. This results in muscle contraction and force production.
5. ATP binds to the myosin head, causing it to detach from actin.
6. The ATP is hydrolyzed into ADP and inorganic phosphate, providing the energy for the myosin head to return to its cocked position.