I am currently taking a biology class. I do not understand this concept. I understand that the electrostatic repulsion of the negative charges, resonance stabilization and hydration stabilization all contribute. However, I do not understand why an increase in entropy would help. Wouldn't it be more favorable to have less entropy in a system?
The phosphoryl transfer potential is one way to think about the free energy available to do useful work when ATP is hydrolysed.
As you can see from the free energy equation below, a positive change in entropy will help to decrease (i.e. make more negative) the free energy change.
This is why an endothermic reaction can still occur spontaneously if the entropy change is big enough to create an entropy term that outweighs the enthalpy term in the Gibbs free energy equation.