AP BIOLOGY

Detailed explanation-1: -Exactly how much free energy (∆G) is released with the hydrolysis of ATP, and how is that free energy used to do cellular work? The calculated ∆G for the hydrolysis of one mole of ATP into ADP and Pi is −7.3 kcal/mole (−30.5 kJ/mol).

Detailed explanation-2: -ADP is continually converted to ATP by the addition of a phosphate during the process of cellular respiration. ATP carries much more energy than ADP. As the cell requires more energy, it uses energy from the breakdown of food molecules to attach a free phosphate group to an ADP molecule in order to make ATP.

Detailed explanation-3: -ATP is like a charged battery, while ADP is like a dead battery. ATP can be hydrolyzed to ADP and Pi by the addition of water, releasing energy. ADP can be “recharged” to form ATP by the addition of energy, combining with Pi in a process that releases a molecule of water.