Does ADP turn back to ATP after releasing energy?

Question

ATP has 3 phosphates (correct me if i'm wrong), for an endergonic reaction to occur (usually related to proteins, yeah?) the ATP loses a phosphate and becomes ADP. The phosphate bonds with the protein and gives it energy for it to "work". After the protein did what it had to do, the phosphate breaks away from the protein. Where does this phosphate go? Does it go back to an ADP and bond with it again? Wouldn't that require a lot of energy as well (cause I thought the energy is already used up by the protein)? My textbook says it's a cycle where ATP --> ADP and ADP --> ATP, but how does that even work?

oh and, correct me if i said anything wrong or confusing, thanks

Answer 1

Yeah, the ADP is recycled back into ATP by binding with a phosphate, the energy being provided by the breakdown of glucose. Glycolysis, Krebs cycle, and the electron transport chain all synthesize ATP from ADP (which is the main purpose of these reactions in the first place).

ADP is also returned to ATP in other ways. For example in the muscles, phosphocreatine donates its phosphate to ADP.

Answer 2

while ATP breaks it creates a ADP and a phosphate, The ability from the ATP breaking is the place the ability is produced. and interior the process the krebs cycle and glycolosis is the place phosphate and ADP combine to make ATP returned. So ATP is the "good stuff"