Q:

What is the role of calcium in muscle contractions?

A:

Calcium is a crucial part of muscle contraction. The ionic element is released from muscles during contraction and relaxation. The release of calcium helps propagate the muscle contraction and relaxation stages.

Action potentials are electrical signals that tell muscle tissue to contract. As an action potential reaches a muscle cell, it triggers calcium to release from the sarcoplasmic reticulum of the cells. The calcium ions then flow into the cytoplasm and bind to the troponin and tropomyosin molecules in the actin filaments of the muscle cells. The binding of calcium allows the troponin to change shape and expose the actin-myosin binding site. Myosin then connects to actin, and the formed complex forms a cross bridge that opens and closes and allows the muscle cells to contract. After the contraction and action potential is over, the calcium channels close, and calcium is removed from the muscle cells.


Is this answer helpful?

Similar Questions

  • Q:

    Where are calcium ions stored in the muscle fiber?

    A:

    Calcium is stored in the terminal cisternae in the sarcoplasmic reticulum of the muscle cell. Calcium ions are stored there until muscle contraction occurs. During muscle contraction, calcium ions are released in order to initiate the contraction.

    Full Answer >
    Filed Under:
  • Q:

    What role does ATP play in muscle contraction?

    A:

    According to the Fayette County Public Schools, the breakdown of adenosine triphosphate (ATP) in a chemical reaction with water provides energy for skeletal muscles to contract. Since the amount of ATP stored in muscles is small, metabolic pathways that generate new ATP must be activated for continued muscle contraction. These pathways are either anaerobic (in the absence of oxygen) or aerobic (in the presence of oxygen).

    Full Answer >
    Filed Under:
  • Q:

    What are dynamic and static contractions?

    A:

    A static (or isometric) contraction occurs when a muscle generates force while the joint angle remains the same. An example would be what happens when a person pushes against a wall. The muscles contract but the joint remains unmoved. A dynamic (or isotonic) contraction occurs when the force generated by the muscle causes movement in the joint. Dynamic contractions occur during most physical activities.

    Full Answer >
    Filed Under:
  • Q:

    What does calcium smell like?

    A:

    Calcium is odorless. It can have a solid, gray-white complexion or a softer, silver-white color.

    Full Answer >
    Filed Under:

Explore