we've gone through beta oxidation we have a lot of of cetal COA what happens if we have too much AC cetal COA so what's going to occur is what we call ketogenesis and that is what this video is about so ketogenesis is going to happen Whenever there is an excess of acetyl coate but not enough oxyacetate remember for our citric acid cycle the very first step is combining a molecule of aceto coate with a molecule of oxaloacetate now if there's not enough oxaloacetate you're going to have an abundance of acetyl COA and so we need to know what to do with that acetyl Co important that you know all of the steps of all of these reactions but what is important is we're going to take two molecules of acoa so you can see this two right in front so there's two molecules there we're going to combine it through a series of steps and we're going to get out at the end acetone and this beta hydroxy butyrate now acetone is what we would call a ketone because we've got that carbonal between two carbons and um when we're doing looking at this in clinical laboratories what they're looking for is what's called Ketone bodies so acetone itself is going to have a very distinct smell that you can smell on the breath of people or in the urine of people who are going through ketogenesis now why you might be going through ketogenesis could occur for a variety of reasons uh one it could be that you are diabetic and you're not able to uptake glucose so your body thinks that it is going through starvation and so in that case it will start burning first your glycogen stores when those get depleted then it will start burning your fatty acid stores and so because it's exclusively using your fatty acids for energy you're going to be generating a lot of acetal Co so this is one of the reasons why um if you are a diabetic they're going to test that by looking at the amount of Ketone bodies or acetone in your urine is to see how much ketogenesis are you going through another reason you could be going through ketogenesis could be starvation and so in Starvation you're going to use up your glycogen stores you're not going to be getting a lot of glucose in your diet so you will start synthesizing fatty acids to use as a primary energy source generating a lot of acetyl COA which then will need to get trans which you'll have too much and eventually you'll need to convert some of it to acetone and beta hydroxy berate and in fact SM um completely healthy individuals can go through and do go through ketogenesis just from some fasts or from even just overnight sleeping before you have your breakfast and so it is a completely normal process it isjust it can also be a symptom of disease in people where this has gone to the extreme okay the use of beta hydroxy butyrate is not just in um so I guess what do we use this beta hydroxy berate for this molecule is used as an energy molecule so beta hydroxy berate will be exported from the liver to other tissues as an energy source and it's primarily going to be transported to your brain so your brain is very good at taking this beta hydroxy mate and using it for energy and so this is actually one of the reasons why uh diabetics are going to have tingling in their fingers and and their toes their extremities is because this beta hydroxy butyrate is going to be used as an energy source but it's going to be transported to your brain because in the mode that your body thinks you're starving which is what is actually occurring in in diabetes um when your body thinks that it's starving and going into starvation mode its job is to prever preserve the brain not your fingers not your toes so you get tingling because this molecule is not being exported to those tissues okay so we take this beta hydroxy berate and we transport it into the brain so how are we going to get energy from that so this this beta hydroxy butter rate it's four carbons long we're going to first reduce it to make some nadh so we can get some energy there from our nadh um going through our electron transport chain and we're going to make this acetoacetate this acetoacetate will combine um with our well I guess it's really a transferase reaction where we're transferring this COA group from cinal COA to this acetoacetate to give us this aceto this aceto actil COA we do ayolas reaction so we saw thas reactions when we were doing our beta oxidation uh to give us two molecules of AAL COA so we're going to use this cetal COA for energy going through our citric acid cycle okay I know you're what you're thinking wait a minute the whole reason that we were doing this was because we had too much acetal COA to go through our citric acid cycle yes but remember our body thinks that it's starving at this point so it's transporting all this um but rate to the brain and there isn't like there's no oxelo acetate there is some so we're going to shut down anything that is going to take our Oyo acetate and convert it to anything else any of the molecules from the citric acid cycle we're going to make sure that they're going through the citric acid cycle they're not being turned into proteins they are not being turned into anything else um they are simply going to be used for fuel and energy so there's a whole lot of bodily processes that are going be shutting down because our body thinks we're starving because we have so much acetyl COA so those few molecules of acetal COA that we get are going to go through our citric acid cycle uh we're going to be generating nadh fadh2 that ATP and so we're going to get about 10 molecules of ATP per molecule of aetl COA so we are going to go through that citric acid cycle but we're going to shut off any of those side processes that are associated with molecules in our our citric acid cycle um and we're cutting off all we're going to be cutting off our acetyl Co or that that butter rate being delivered to anywhere else in our body because our body is shutting down and going into starvation mode okay so what will then happen is this ketogenesis again we're going to get these large levels of acetone and this beta hydroxy butyrate and this can be detected in diabetics in their their blood and in their urine by the acetone and you can also detect it on their breath often as well so when you're doing these P tests here what they're looking for is concentration of acetone in your urine so um this will tell you the concentration that you have and so how significant is the ketogenesis that you're occurring that you're going through