Question

What role does calcium play in this regulation, and where is it stored in a muscle fiber?

Answer 1

1) calcium triggers contraction by reaction with regulatory proteins. two different regulatory system are found in different muscles. in actin- linked regulation troponin and tropomyosin regulate actin by blocking sites on actin required for complex formation with myosin.calcium binding and regulation of molluscan myosin depend on the presence of regulatory light chains it is proposed that the light chain function by sterically blocking myosin sites in the absence of calcium and that the off state of myosin requires cooperation between the 2 myosin head and both myosin control and actin control are widely distributed in different organisms.

2) muscle cells contract with assistance of calcium . sarcoplasmic reticulum of muscle cells stores calcium and releases it when stimulated by the nervous system which leads muscle contracttion ,calcium is essential in muscular contraction because it helps facilitate the binding of actin and myosin , the 2 myofilaments responsible for contracting the muscle .inside each muscle fiber these 2 myofilaments are next to one another. calcium ions play an important role in signal transduction pathways.