Description | Animals obtain their energy by oxidation of foods, plants do so by trapping the sunlight using chlorophyll. However, before the energy can be used, it is first transformed into a form which the organism can handle easily. This special carrier of energy is the molecule adenosine triphosphate, or ATP. The ATP molecule is composed of three components. At the centre is a sugar molecule, [[ribose] (the same sugar that forms the basis of DNA). Attached to one side of this is a base (a group consisting of linked rings of carbon and nitrogen atoms); in this case the base is adenine. The other side of the sugar is attached to a string of phosphate groups. These phosphates are the key to the activity of ATP. ATP consists of a base, in this case adenine (red), a ribose (magenta) and a phosphate chain (blue). 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, contact muscles, etc. |