How Is Energy Released From ATP?

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Energy is released from ATP by the breaking of the phosphate bond, states the University of Illinois at Chicago. Adenosine triphosphate, or ATP, consists of a sugar called ribose, the molecule adenine and three phosphate groups. During the hydrolysis of ATP, the last phosphate group is transferred to another molecule, thus breaking the phosphate bond. This reaction causes energy to be released to power other activities within the cell.

ATP is made by breaking down glucose, as stated by Dr. Dawn Tamarkin at Springfield Technical Community College. By breaking down the bonds in glucose in the presence of oxygen, energy is produced in order to add a phosphate group to ADP to form ATP. In this way, 38 ATPs are formed. This process is called cellular respiration.

The energy of the ATP molecule lies in the bonds between the phosphate groups, or pyrophosphate bonds, states Dr. Mike Farabee of Estrella Mountain Community College. The bond between the second phosphate and last phosphate groups yields the most energy, about seven kilocalories per mole. When this bond is broken, adenosine diphosphate, or ADP, is formed.

Because ATP is constantly being used, it needs to be replenished. A single muscle cell, probably one of the greatest users of ATP, uses and replenishes 10,000,000 ATP molecules per second, according to the University of Illinois at Chicago.