in this video we're gonna talk about the ATP cycle so let's begin with a molecule called ADP ATP is adenosine diphosphate and it has two phosphate groups now we're gonna convert this to ATP adenosine triphosphate which has three phosphate groups so to show that visually here's what we can do I'm gonna put a four adenosine and the two phosphate groups there an ATP has three phosphate groups now in order to make ATP from adp we need an inorganic phosphate now ATP has more energy than ADP so in order to go from adp to ATP we need to put energy in to this process so because we've put in energy in this is going to be an endergonic reaction or an endergonic process anytime energy is absorbed in reaction you have an endergonic reaction now let's talk about the other part of the cycle convert an ATP to adp in this case we need to lose a phosphate group so a phosphate group is going to come out of the cycle now on the first half or on the left side we put in energy to make ATP so in this case energy is going to come out the right side is basically the reverse of the left side so we're going from a molecule that has more energy to a molecule that has less energy so this energy will be released now because we're released in energy and that process is known as an exergonic process anytime energy is released in a reaction it's an exergonic reaction now there's one more thing that we need and that is water to convert ATP to ADP we need water and so this is a hydrolysis reaction we need to use water to break one of the phosphate bonds now if the right side is a hydrolysis reaction the left side must be a dehydration synthesis reaction so water is release on the left side so that is the ATP cycle that's how adp converts into ATP and vice-versa now let's summarize the reaction another way so when we combine ATP with water we're going to make adp adenosine diphosphate and we're going to release a phosphate group and we're going to get energy in the process so that is an example of the hydrolysis reaction and as you said before this is an exergonic reaction since energy is released now on the other side we have adp reacting with inorganic phosphate and we need to put in energy to make this work and we're going to produce ATP and we're going to release water as a by-product so this process is a dehydration synthesis reaction because we're forming a bond and we're releasing water we're forming a bond between the two phosphate groups so because we're putting in energy or because energies on the left side of the chemical equation and this is an endergonic reaction we need energy to drive this reaction for it and so that's the ATP cycle in order to make ATP you need to put energy into it so ATP is a form of short-term energy storage but once we convert ATP back into ATP then that energy that was stored can be released to do useful work such as power and active transport or synthesizing molecules or even Drive in other endergonic reactions so ATP is the energy currency of the cell it's very useful for getting things done and accomplished in many cellular processes so that's it for this video thanks for watching and don't forget to subscribe