AP BIOLOGY

Detailed explanation-1: -If a cell needs to spend energy to accomplish a task, the ATP molecule splits off one of its three phosphates, becoming ADP (Adenosine di-phosphate) + phosphate. The energy holding that phosphate molecule is now released and available to do work for the cell.

Detailed explanation-2: -These three phosphate groups are linked to one another by two high-energy bonds called phosphoanhydride bonds. When one phosphate group is removed by breaking a phosphoanhydride bond in a process called hydrolysis, energy is released, and ATP is converted to adenosine diphosphate (ADP).

Detailed explanation-3: -Energy is released because the products (ADP and phosphate ion) have less energy than the reactants [ATP and water (H2O)]. If the hydrolysis of ATP releases energy, its synthesis (from ADP) requires energy.

Detailed explanation-4: -When ATP, the cell’s energy currency, is hydrolyzed to generate ADP and inorganic phosphate, energy is released.

Detailed explanation-5: -Although cells continuously break down ATP to obtain energy, ATP also is constantly being synthesized from ADP and phosphate through the processes of cellular respiration. Most of the ATP in cells is produced by the enzyme ATP synthase, which converts ADP and phosphate to ATP.