Enzymes are proteins that speed up reactions by   1. providing an additional energy source  2. supplying additional molecules for the reaction     3. removing inhibitors that slow down reactions 4.   lowering the amount of energy required

What happens as electrons move along the chain of molecules known as the electron transport chain? they gain energy, which causes atp molecules to lose phosphate groups. they gain energy, which causes h *ions to join with oxygen to produce water. they lose energy, which is then used by the cell to make atp. they lose energy, which is then used to break down atp.