Hydrolysis of the phosphate groups in ATP is especially exergonic, because the resulting inorganic phosphate molecular ion is greatly stabilized by multiple resonance structures, making the products (ADP and Pi) lower in energy than the reactant (ATP).

ADP is combined with a phosphate to form ATP in the reaction ADP+Pi+free energy→ATP+H2O. The energy released from the hydrolysis of ATP into ADP is used to perform cellular work, usually by coupling the exergonic reaction of ATP hydrolysis with endergonic reactions.

chemical energy
adenosine triphosphate (ATP), energy-carrying molecule found in the cells of all living things. ATP captures chemical energy obtained from the breakdown of food molecules and releases it to fuel other cellular processes.

ATPases
ATPases are a group of enzymes that catalyze the hydrolysis of a phosphate bond in adenosine triphosphate (ATP) to form adenosine diphosphate (ADP). They harness the energy released from the breakdown of the phosphate bond and utilize it to perform other cellular reactions.

one ribose molecule
An ATP (adenosine triphosphate) molecule is made up of one ribose molecule, one adenine molecule, and three phosphate groups joined.

enzyme ATP synthase
Most of the ATP in cells is produced by the enzyme ATP synthase, which converts ADP and phosphate to ATP. ATP synthase is located in the membrane of cellular structures called mitochondria; in plant cells, the enzyme also is found in chloroplasts.

Thus, ATP is the higher energy form (the recharged battery) while ADP is the lower energy form (the used battery). When the terminal (third) phosphate is cut loose, ATP becomes ADP (Adenosine diphosphate; di= two), and the stored energy is released for some biological process to utilize.

Ribose is a simple sugar made in the body from glucose. Ribose plays an important role in the synthesis of RNA, DNA and the energy containing substance adenosine triphosphate (ATP). FUNCTIONS. Adenosine triphosphate (ATP), is a high energy molecule in cells that is generated within the mitochondria.

ADP
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).

By the same token, the free energy required to synthesize ATP from ADP and P i under the conditions prevailing in the erythrocyte would be 51.8 kJ/mol. Because the concentrations of ATP, ADP, and P i may differ from one cell type to another (Table 13-5), ΔG p for ATP hydrolysis likewise differs.

This problem has been solved! Adenosine triphosphate (ATP) is considered the energy currency for the cell. This molecule is energy-rich in part due to its two phosphoanhydride bonds. Resonance structures for ATP are given below, where X represents adenosine monophosphate (AMP).

ATP also fuels mechanical work in other types of cells. An important example in humans is muscle contraction, which is caused by the sliding of actin and myosin filaments past each other in muscle cells. In this case, ATP hydrolysis allows the cyclical interaction between actin and myosin to continue during a contraction.

ATP is composed of the nitrogenous base adenine, a ribose sugar, and a chain of three phosphate groups. The unstable phosphoanhydride bonds permit transfer of phosphate groups to other molecules. Energy is a fundamental necessity for all of life’s processes.