The molecule synthesized by cells to provide energy is adenosine triphosphate (ATP). ATP is a small molecule that is often referred to as the "energy currency" of the cell, as it is used to power a wide variety of cellular processes. ATP is composed of a nitrogenous base (adenine), a sugar (ribose), and three phosphate groups. When the phosphate groups are broken down, energy is released that can be used by the cell to perform various functions. ATP is produced in cells through a number of metabolic processes, including glycolysis, the citric acid cycle, and oxidative phosphorylation.