hi everyone welcome back today's video is about glycogenesis if you want to skip to any particular section of this video you can do so by clicking the timestamps found in the description section below also please make sure to subscribe to our Channel as this help that channel out a lot okay let's get to the video glycogenesis is the process by which glucose molecules are assembled into glycogen and stored so let's briefly go over glycogen and then explore the process of glycogenesis glycogen is a large branched polysaccharide it's made up of glucose units connected by Alpha buag glycidic Bonds in linear chain however this molecule is Branched and the branches are connected with the alpha6 glycosidic bond and are found at points approximately every 8 to 12 glucose residues due to its branched nature glycogen forms dense spherical granular within cells these granules are found in the cytoplasm of liver and muscle cells these liver and muscle cells consist of both glycogen and enzymes needed for glycogen metabolism the highly branched nature also allows for Rapid enzymatic access to glucose at the branch points this enables quick release of glucose when needed now that we know what glycogen is let's talk about how it's made we know that glycogenesis is a process by which glucose molecules are assembled into glycogen and stored it's essential for regulating blood glucose levels and maintaining a reserve of readily available energy it occurs in several steps and is most active when blood glucose levels are high an example of this instance is after a high carbohydr meal there are four steps in glycogenesis this includes the activation of gluc Primal formation by glycogenin elongation by glycogen synthes and branching by the branching enzyme let's go through each of the steps in more detail activation of glucose the process of glycogenesis starts when glucose enters the cell and is phosphorilated to form glucose 6 phosphate this is also called g6p This phosphorilation is catalyzed by hexokinase in muscle cells or glucokinase in liver cells the phosphorilation helps retain glucose within the cell by preventing it from diffusing back out g6p is then isomerized by the enzyme phosphoglucomutase to produce glucose one phosphate which is also called g1p this conversion is essential because g1p is a substrate that reacts with urin triphosphate also called UTP to form urine diphosphate glucose which is also abbreviated as UDP glucose UDP glucose is a high energy precursor necessary for the polymerization step that follows once UDP glucose is formed it serves as the immediate substrate for the enzyme glycogen synthes this is a key regulatory enzyme of glycogenesis now let's go to step number two Prim formation by glycogenin glycogen synthes which we referred to before requires an initial primer this is provided by a protein called glycogenin glycogenin has an autog glycosylating ability this means that it can attach glucose residues to itself forming a small glycogen primer then glycogen synthes can extend this glycogen primer this glycogen and glycogen core serves as the starting point for further glucose addition now let's move to step number three elongation by glycogen synthes glycogen synthes adds glucose units from UDP glucose to a growing glycogen Chain by forming Alpha one4 glycosidic bonds glycogen synthes is tightly regulated and becomes active in response to insulin insulin signals a higher energy state in the cell and promotes glucose storage and finally we have the fourth step branching by the branching enzyme an essential feature of glycogen is its highly branched nature this increases its solubility and allows for Rapid synthesis and breakdown of glycogen molecules the branching enzyme introduces Branch points to glycogen by cleaving an alpha1 for glycosidic bond in the linear glycogen chain then the cleaved linear glycogen chain is reattached via an alpha one6 glycosidic Bond at least four glucose residues away from an existing Branch this process creates a highly branched structure branching enhances the number of terminal ends of glycogen molecules where enzymes can add or remove glucose units allowing for efficient storage and mobilization of energy that's it for this video I hope this video was helpful for you if it was please make sure to subscribe and like our Channel and also check out all of our other videos of this channel as well see you in the next video bye