ABSTRACT
All living things, plants and animals, require a continual supply of energy in order to function. The energy is used for all the processes which keep the organism alive. Adenosine triphosphate (ATP) works by losing the endmost phosphate group when instructed to do so by an enzyme. This reaction releases a lot of energy, which the organism can then use to build proteins, contract muscles, generate heat. When the organism is resting and energy is not immediately needed, the reverse reaction takes place and the phosphate groups are reattached to the molecule, one at a time, using energy obtained from food or sunlight. Thus, the ATP molecule acts as a sort of rechargeable ‘chemical battery’, storing energy when it is not needed, but able to release it instantly when the organism requires it. In plants, the ATP is recycled in the cell membranes of chloroplasts.
