ATP: Adenosine triphosphate

ATP or adenosine triphosphate is often referred to as the currency of energy or the energy score adenosine the energy store in biological systems and what I want to do in this video is get a better appreciation of why that is so identity seen tri phosphate so at first this seems like a fancy a fairly complicated term adenosine triphosphate and even when we look at its molecular structure it seems quite involved but if we break it down into its constituent parts it becomes a little bit more understandable and we'll begin to appreciate why it's how it is a store of energy in biological systems so the first part is to break down this molecule between the part that is adenosine and the part that is the tri phosphates or the 3 phosphoryl groups so the adenosine is this part of the molecule let me do it in that same color so this part right over here is adenosine and it's an adenine with with connected to a ribose right over there so that's the adenosine part and then you have 3 phosphoryl groups and when they break off they can turn into a phosphate and so the the triphosphate part you have so triphosphate you have one phosphoryl groups two phosphoryl groups two phosphoryl groups and three phosphoryl groups so one way that you can conceptualize this molecule which will make it a little bit easier to understand how it's a store of energy in biological systems is to represent the D this whole adenosine group let's just represent that as an A actually let's make it that an ad and then let's just sew it bonded to the 3 phosphorylate the P and a circle around it so you could do it like that or sometimes you'll see it actually depicted instead of just drawing these straight horizontal lines you'll see it depicted with essentially higher energy bonds so you'll see something like C something like that to show that these bonds have a lot of energy but I'll just I'll just do it I'll just do it this way for the sake of this video but these are high energy bonds now what does that mean what does that mean that these are high energy bonds it means that the electrons in this bond are in a high energy state and if somehow this bond could be broken these electrons are going to go into a more comfortable state into a low or energy state and as they go from a higher energy state into a lower more comfortable energy state they are going to release energy one way to think about it is if I'm about to jump on my climate in a plane and I'm about to jump out I'm at a high energy state I have a high potential energy I just do a little thing and I'm gonna fall through I'm gonna fall down and as I fall down I can release energy I can there will be friction with the air eventually when I I guess hit the ground that you know that that will release energy I could compress a spring or I can move a turbine or who knows what I could do but then when I'm sitting on my couch then I'm at a low energy state I'm comfortable it's not obvious of you know how I could go to a lower energy State I guess I could fall asleep or something like that and these metaphors break down at some point but well that's one way to think about what's going on here the electrons in this bond if you can if you can give them just the right circumstances they can come out of that bond and go into a lower energy state and release energy so one way to think about it you start with a you start with ATP adenosine triphosphate and one possibility you put it in the presence of water and then hydrolysis will take place and what you're going to end up with is one of these things are going to be essentially one of these phosphorylate into a phosphate molecule and so you're going to have then adenosine since you don't have three phosphoryl groups anymore you're only going to have two phosphoryl groups you're going to have a dentist scene dye phosphate often known as adp so let me write this down this is a TP this is a TP right over here and this right over here is a DP die for two two phosphoryl groups adenosine diphosphate and then this one got plucked off this one gets plucked off or it pops off and it's now bonded to the oxygen and one of the hydrogen's from the water molecule and then you could have another hydrogen proton but the really important part of this I have not drawn yet the really important part of it as the electrons in is the electrons in this bond right over here go into a lower energy state they are going to release energy so plus plus energy so here this this side of the reaction energy released energy released and this side of the air action you see energy energy stored and so as you study biochemistry you will see time and time again energy being used in order to go from ADP and a phosphate to ADP so that stores the energy you'll see that in things like photosynthesis where you use light energy to essentially eventually get to a point where this P is put back on using energy putting this P back on to the ADP to get ATP and then you'll see when when biological systems need to use energy that they'll use the ATP and they'll essentially hydrolysis will take place and they'll release that energy sometimes that energy could be used just to generate heat and sometimes it can be used to actually forward some other reaction or you know change the conformation of a protein some out whatever whatever might be the case