Discuss how calcium is a signaling molecule that causes the contraction of the sarcomere.  This discussion should include the molecular mechanisms of tricep contraction.

31) Provide one difference and one similarity in the process of contraction of smooth, skeletal, and cardiac muscle. These could include channels, mechanisms, anatomic features etc (SHORT ANSWER PLEASE)

With regard to muscle contraction, which of the following is an INCORRECT statement with regard to the interactions of filaments that occur in the sarcomere? A. When muscles are relaxed tropomyosin blocks binding sites on actin subunits, which keeps cross-bridges from forming. B. The myosin heads conduct a power stroke motion to slide when bound to actin, to move the "thin" filaments towards the center of the sarcomere. C. During contraction, actin subunits are removed from the ends of the "thin" filaments to shorten actin polymers, thus reducing the length of the sarcomere. D. "Thick" filaments are anchored at the M-line, while "thin" filaments are anchored at the Z-line. E. Numerous myosin heads engage with the actin filaments simultaneously, such that there is no back-slipping during the contraction process.

3.4. About human skeletal muscle contraction, what are the correct statements? PHYSIOLOGY_basic (OJO) A muscle fiber is made by the parallel apposition of sarcomers. Generation of force relies on the formation of cross-bridges between actin and myosin filaments. In the process of contraction, adenosine triphosphate (ATP) is required both to drive the actin-myosin association-dissociation cycle and to recycle calcium back to the endoplasmic reticulum. Each muscle fiber is innervated by one neuron only. T tubules are plasma membrane invaginations of the sarcolemma that allow excitation-contraction coupling.