Final answer:
Calcium, released by the sarcoplasmic reticulum, binds to troponin to move the tropomyosin, which allows actin to form of a complex with myosin. This binding of calcium ions to troponin causes a conformational change in the sarcomere, facilitating muscle contraction.
Step-by-step explanation:
Calcium ions released by the sarcoplasmic reticulum bind to troponin to move the tropomyosin, which allows actin to form a complex with myosin. Calcium, as the most abundant mineral in the body, has its majority stored in the bones, acting as a reservoir for maintaining calcium levels in the blood and tissues.
Any disruptions in the calcium levels can lead to hypo- or hypercalcemia. Furthermore, calcium ions are involved in the transmission of nerve impulses, muscle contractions, including that of the heart, and are integral in the stabilization of cell membranes for the release of neurotransmitters and hormones.