What about the structure of ATP makes it useful as an energy currency of cells?

Answer 1

The ATP structure is has a carbon backbone but the 3 phosphate or triphosphate is the useful part. They connect to oxygen molecule on all 4 sides and with oxygen being negatively charged they have lots of potential energy. By removing 1 phosphate group will change ATP to ADP and that allows organisms to use this energy as currency.

Answer 2

Adenine triphosphate is unstable, because the part of the molecule containing the three phosphates is off balance from the rest. All it takes is removing one of the phosphates to make it stable, and doing so releases energy.

Answer 3

Adenosine triphosphate is made up of adenosine (adenine +ribose) and three phosphate groups. The energy store in the molecule is caused by the electron configuration. The three phosphate groups have a total of 4 negative charges confined in a small area. These charges repel each other, so this makes the potential energy of the molecule very high. When ATP undergoes hydrolysis: ATP + H2O --> ADP + P the ADP and P are stablalized be cause the electrons are distributed between the ADP and the phosphate. The hydrogens from the water also surround the phosphate to reduce the charge. The hydrolysis of ATP is exergonic (spontaneous) in other words this reaction can do work on its surroundings. The organisms harnesses this work by using this free energy to phosphorylate ( to add phosphates to) molecules.

Phosphorylating molecules allows many reactions to occur that are not spontaneous. For example, phosphorylation polymerizes monomers (lower energy) into polymers (higher energy). In these reactions ATP directly phosphorlyates a substrate monomer. The substrate is becomes high in potential energy because the phosphate has two negative charges. The high energy substrate now has the ability to react to form a product polymer, because the product molcule is lower in energy than the phosphorylated substrate. The energy ATP has, is also used in phosphorlation of proteins. When a protein is phosphorylated, the phosphate causes a conformational change that alters the proteins shape and function. Phosphorylation can essentially move part protein, an actuality this process is responsible for the movement of our bodies, ion pumps, movement of molecules, and other tasks a cells do.