What is the function of calcium ions during muscle contraction

The calcium ions play a major role in providing muscle contraction. The calcium ions are released by sarcoplasmic reticulum in the phenomenon of muscle contraction. For allowing a muscle to contract, the calcium ions binds to the troponin, which is a complex of protein. As a result of this binding, the active binding sites of the actin microfilaments gets exposed. Gaps are formed, which are readily filled by the myosin. As a result, cross- bridges is formed which allows the muscle to contract.

where in your body is there an enzyme that does function at a high or low ph? what is the name of that enzyme and its function?