ATP:

Before cells can use the energy of sunlight or that stored in carbohydrates, they must transfer the energy to molecules of ATP (adenosine triphosphate). ATP is composed of adenine, ribose, and three phosphate groups. ATP transfers energy to many different chemical reactions. Almost all metabolic pathways directly or indirectly run on energy supplied by ATP. Energy input links phosphate to ADP to produce ATP. ATP can donate a phosphate group (phosphorylation) to another molecule, which then becomes primed and energized for specific reactions. ADP can be recycled to ATP very rapidly.