[Music] hello everybody this is andy from med school eu and we're finally moving on to a new topic in the biology section from the imats specifications and that's going to be bioenergetics and the first part that we will talk about is called the energy currency of cells and more specifically we will discuss the molecule of atp so atp stands for adenosine triphosphate so it's got the adenosine group and three phosphates attached to it so we're going to take a look at exactly the structure of it but before we do that we must we must recognize that atp is an energy carrier because of the rich energy bonds that it has so let's let's look at the chemistry of atp and figure out exactly why atp is able to carry so much energy within it so what we have here this is the atp molecule all together now here starting from the right side of the blue this is a nitrogenous base which is adenine so let's label that as uh adenine adenine so adenine actually comes from the name here adenosine which is a nucleoside and just to know exactly what a nucleoside is it's basically this adenine molecule so the nitrogenous base plus the five carbon sugar and if you could recall nucleotides that we have talked about previously what they have is is basically a nitrogenous base adenine guanine cytosine thymine uracil it would be a nitrogenous base this one it has two rings so it's a purine and it's attached to a five carbon sugar and it would be attached to one phosphate one single phosphate and this would make up a nucleotide however the difference between the nucleotide and atp is that it has three phosphates here instead of just the one and we will discuss the significance of that because that is where all the energy of the atp actually comes from so let's continue to describe the the molecule here again this is adenine this is the five carbon sugar so that would be five carbon sugar and of course it's linked to phosphate i'm not going to um it would be triphosphate here so i'm not going to label everything here however we are going to go over the bonds that exist between there so if this is a carbon molecule this is ch2 right here we don't label it however it's it's a ch2 carbon to oxygen to phosphate this makes up an ester bond so here we will write it as ester that's an ester bond and ester bond actually releases 14.2 kilojoules per mole of energy and you don't need to remember the numbers for the exam of course however i i'm just gonna provide the numbers so you understand how much energy would release if the atp molecule was hydrolyzed at the ester bond so if it was hydrolyzed right here and all the phosphates would be gone so the triphosphate would remain intact and it would just be dissociated from the atp now the atp just becomes a nucleoside where it's uh it's just adenosine adenine and five carbon sugar that's called a nucleoside and more specifically because it's adenine nitrogenous base it would be called adenosine instead of just a nucleoside so next moving on these two bonds so between phosphate oxygen and phosphate so right here this bond and this bond these two bonds are called anhydride bonds so let's label them as and high dried anhydride bonds and more specifically it would be called phospho-anhydride bonds because they're within phosphate groups now the significance about these phos phosphon hydride bonds is that they release a whole lot of energy if they're hydrolyzed so what we have for this one it would be 30.5 kilojoules per mole and this one would be 32.8 kilojoules per mole so as you can see this this is over double the amount of energy that is released from just hydrolyzing the ester bond so what we have is most predominantly we just get released this furthest phosphate now how how we label them is that this phosphate is called the alpha phosphate like this this phosphate is called the beta phosphate and this one is called the gamma phosphate all right so now that we understand that the anhydride bonds actually provide a lot more energy if they're hydrolyzed now let's take a look at the structures that resolve from hydrolysis of these anhydride bonds first of all if we were to cut and separate the molecule like this we would end up with this adp and this is what we see most predominantly we have a dp which stands for adenosine diphosphate because it's adenosine with two phosphates attached to it plus it would result in inorganic phosphate we call this pi inorganic phosphate because it's just phosphate that would be floating around on its own and the hydrolysis of this and we see this in a lot of different reactions especially in glycolysis is that atp in the first part of glycolysis atp is used to generate energy in order to create the the products and and actually go through the for the reaction now it obviously releases 30.5 kilojoules per mole energy and this energy would be used for the reactants in order for them to get through the activation energy and become the products and what we end up with is the adp molecule plus the inorganic phosphate and the other very common scenario if we snap the if we hydrolyze the atp molecule at the beta phosphate so that would be right here so it's hydrolyzed like this what we end up with is that we have an amp molecule and this occurs as well amp molecule plus and this would be called pyrophosphate pyro phosphate so the two phosphates attached together is just called pyro phosphate now the pyrophosphate could also be hydrolyzed again to create two inorganic phosphates so this would be two inorganic phosphates plus the molecule of amp which stands for adenosine monophosphate because it just has the one alpha phosphate attached to it and we're going to see atp in a lot of the upcoming videos and where these anhydride bonds are hydrolyzed we're going to refer back to this structure what you really need to remember is that atp contains anhydride bonds that are full of energy and therefore when we hydrolyze them we receive all this energy to carry out our reactions so this concludes the video for today and in the next lecture we're going to talk about redux reactions and living things [Music] you