Conservation of Energy in the Heart physics questions? Will give 10 pts!?

1) the source of energy comes from gate in cells opening when they are stimulated with a hormone. when the cell is stimulate, Na+ ion channels open, allowing for ions to go in the cell changing the electric potential and depolarizing the cell. then the Na+ gate closes and the K+ channels open allowing K+ to rush outside the cell, which re-polarizes the cell, this happens until it gets back to resting state. the ions moving across the cell is the source of electricity.