Question

What role does calcium play in muscle contraction?

Answer 1

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.   this is from this site:https://www.reference.com/science/role-calcium-muscle-contractions-e42334f57f1a7187 
Plagiarism is wrong lol so there is is ^^^^