Remember in chemistry where some reactions are endothermic and others are exothermic? One requires energy to make the reaction happen and the other gives off energy when a reaction happens? (Fire is exothermic, a bunch of heat comes out when you burn wood. A tree growing is endothermic. It takes energy from the sun to slowly assemble wood fibers and build up the wood.)
ATP is a molecule capable of reversible reactions. When you eat, your body uses the food energy to assemble the ATP molecule into a high energy state. When your cell gets that ATP molecule, it can reverse that reaction extracting the energy.
Latest Answers