Final answer:
Adenosine is a nucleoside formed by adenine and ribose, bonded to three phosphate groups to make ATP, which is the primary energy currency of the cell. The high-energy phosphoanhydride bonds between these phosphate groups release energy when broken, powering cellular processes.
Step-by-step explanation:
Adenosine Triphosphate (ATP)
Adenosine is a nucleoside composed of two key components: a nitrogenous base known as adenine and a five-carbon sugar, which in the case of ATP is ribose. Together, they form the adenosine molecule, which is then bonded to three phosphate groups. These phosphate groups are labeled as alpha, beta, and gamma, with the alpha phosphate being closest to the ribose sugar and gamma being the furthest. ATP is crucial in cellular functions as it serves as the main energy currency of the cell.
In the structure of ATP, the bonds that link the phosphate groups are known as phosphoanhydride bonds and are considered high-energy due to the potential energy they store. The energy released from breaking these bonds fuels important cellular processes, including muscle contraction, substance transport, and anabolic reactions.
The three phosphate groups are essential for ATP's function as the energy currency and agent for the transfer of phosphate groups. The hydrolysis of ATP (ATP + H₂O → ADP + P + free energy) is a reaction that releases energy usable by the cell for various metabolic activities.