welcome back to dirty medicine's dirty biochemistry Series in this video we're going to be talking about the hmp shunt now the hmp shunt is also sometimes referred to as the pentos phosphate pathway so you may have heard this refer to as the hmp shunt the hmp the PPP or the pentos phosphate pathway but any of those names that just came out of my mouth all refer to the same thing now before I get into this video I want to start with a quick overview and frame today's video because it's actually part one of two parts in this series so part one is going to be on the hmp shun and as you'll see as we move through this video there's a lot of synergy that takes place between this pathway and the glutathione reductase pathway now the glutathione reductase pathway is going to be part two so I would watch this video first which will be part one on the hmp shunt or the pentos phosphate pathway and then watch part two about the glutathione reductase pathway because again those two Pathways work in tandem with one another they work in this sort of synergistic way where the two pathways are constantly churning out reactants and products that the other one can use so that together they can achieve the body's function when it comes to the biochemical pathway of dealing with free radicals so that's a big overview of what these two videos are going to cover and I don't expect you to be comfortable with this at all right because I haven't talked about it yet so if you're really confused and you're really scared about all these things that just came out of my mouth and I want you to take a deep breath and relax because when you get to the end of these two videos all of this biochemistry will make beautiful sense to you so with that said let's start let's start with part one so part one is on the hmp shunt so the hmp shunt has one goal the main goal of the hmp shunt is to produce nadph okay it is absolutely crucial that through the hmp shunt you get the generation of nadph now the question would be the logical next question would be why do we need nadph well nadp is required for glutathione reduction for fatty acid synthesis and for cholesterol synthesis so in addition to working on glutathione reduction which is going to be in part two of this series it actually also contributes to fatty acid and cholesterol synthesis so nadph is a very valuable factor for the body's biochemical pathways now what we're going to focus on on this video is what you see here in red right glutathione the main goal in part two of this little miniseries if you will is that we need to be able to reduce glutathione right so in order to do that we need nadph so then the next logical question is why the hell do we need glutathione well glutathione is required for free radical detoxification so as you can see here a lot of these Pathways lend itself to one another because they're generating things that The Next Step needs so for example and just to take a big step back free radical detox requires reduced glutathion but reduced glutathione requires nadph and nadph comes from the hmp shunt so really working backwards I could have taught you to the taught this to you and said we need the hmp shun to make nadph to reduce glutathione to process free radicals so as you can see it is really important that we hit these one at a time right we start with the hmp shunt we make nadph nadph allows an enzyme which you'll learn about in part two of this miniseries to reduce glutathione and then reduced glutathione can actually handle free radical detoxification so there's a lot of interworking biochemistry here and you have to understand the big picture in order to really appreciate what's going on and get your questions right on test day so with that said we're going to start again by talking about the hmp shunt and this time we're going to walk through the path way now remember from way earlier in the dirty biochemistry series we talked about glycolysis and glycolysis starts with glucose and the first step in glycolysis is that that glucose actually goes to glucose 6 phosphate now I've shown that here in blue but then of course glycolysis could continue all the way Downstream until glucose is ultimately converted into pyu now the reason that this is relevant when we talk about the hmp shunt is that it's right here at this glucose 6 phosphate stepping glycolysis that that glucose 6 phosphate can actually pivot and leave glycolysis so instead of ultimately being formed into pyruvate it can actually kind of take a U-turn and enter the hmp shunt so this thicker Black Arrow represents the beginning of the hmp shun so our initial Pro our initial reactant here is glucose 6 phosphate leaving glycolysis and going into the hmp shunt now glucose 6 phosphate in the hmp shunt will be converted into six phosphor gluconolactone okay it's a funny name but six phosphor gluconolactone and the enzyme that does that conversion is glucose 6 phosphate dehydrogenase also sometimes referred to as G6PD now G6PD is the highest yield enzyme that you'll need to know in this part one of the hmp shun now just for completeness sake six phospho gluconolactone can actually go through two further steps which will conclude the hmp Shan so it can be con converted into six phosphogluconate by the enzyme gluconolactonase and then that six phosphogluconate can be converted into ribulose 5 phosphate by the enzyme 6 phosphogluconate dehydrogenase but I want to make one thing very very clear for the purposes of USMLE and complex you only need to know the first step of the hmp shun that is to say that you only need to know that glucose 6 phosphate gets converted into six phosph gluconolactone by G6PD also known as glucose 6 phosphate dehydrogenase those final few steps you can know for completeness sake and maybe you should know them for the purposes of inclass exams like your actual biochemistry exam that you're taking in medical school but if you're learning this for the purposes strictly of USM your complex then you only need to know that first step so this is what you should keep in mind this is the big picture of the hmp shine again pretty easy right just one step what's really important to know and becomes incredible high yield is to understand that during this step during this one and only step that you need to know in the hmp shun we actually need nadp+ and we convert it into nadph so that enzyme glucose 6 phosphate dehydrogenase requires NAD nadp plus and during this step we'll convert it into nadph so remember at the start of this lecture I told you that the main and the only goal of the hmp shunt was to produce an adph so you can see that here in blue that it's actually meeting its goal right the hmp shun is converting g6p into six phosph gluconolactone through the enzyme glucose 6 phosphate dehydrogenase and it's during this one and only step that you should know for the purposes of usan complex that nadph is formed from nadp+ so in this one single step the hmp shunt has done for the body's biochemistry what it's designed to do now a couple important points about the hmp shun one it occurs in the cytoplasm two the primary organs where the hmp shunt is taking place is occurring in the liver in the mamory glands and in the adrenal cortex okay so these are some high yield facts about the hmp shunt that you really should memorize so I've got an awesome dirty medicine pneumonic to help you memorize this when I think of hmp Sean I think of hmp hepatic mamory and periphery so H for hepatic tells me that the hmp shun occurs in the liver M for mamory is the second letter in hmp hmp M for mamory so it's occurring in mammory glands and then hmp P for periphery of the adrenal gland so the periphery or the outer part of the adrenal gland is going to be your adrenal cortex so hmp hepatic mammory periphery of adrenal that helps me remember exactly where the hmp shun is occurring so that it that if a question shows up on us your complex about where this is actually happening you've got my awesome dirty medicine pneumonic so here's where we are with the hmp Shan again to quickly summarize we took glucose 6 phosphate and we ripped it right out of the glycolysis first step and that glucose 6 phosphate was converted into six phospho gluconolactone the enzyme that did this conversion was glucose 6 phosphate dehydrogenase this is the one and only step that you should memorize about the hmp shunt now it was during this one and only step that nadp+ was converted into nadph and again the only goal of the hmp shun is to produce nadph it occurs in the cytoplasm it occurs in the liver mamor glands and adrenal cortex which You Remember by saying hmp H for hepatic M for mamory and P for periphery of the adrenal so that's the big summary of what we've talked about so far and just to leave you with a little beautiful conclusion to help segue to part two where we'll talk about glutathione this is where we are so far so g6p gets converted to six phosph gluconolactone and the enzyme glucose 6 phosphate dehydrogenation is doing that conversion but that enzyme is also converting nadp plus into nadph and as we'll soon learn in part two of this little miniseries the generation of nadph fuels some other reactions that this will be very closely tied to please proceed to the next video to learn about glutathione reduction