Glycogen

in this video, we're going to begin our lesson on the Poly Sacha ride glycogen. And so the poly sacha ride glycogen is a homo Polly Sacha ride which, of course, we know from our previous lesson videos just means that glycogen is made up of just one single type of repeating sugar unit and that repeating sugar unit is going to be a D glucose molecule. Now, most of the D glucose molecules and glycogen structure are going to be co violently linked to each other via thes Alfa 14 Glick ascetic linkages. And so the Alfa configuration of the Glick acidic linkage reminds us that Gleick Hodgins function is going to be energy storage. And so you might recall that way back in our previous lesson videos when we talked about glycogen fast for lease that we said glycogen acts as an energy storage molecule in animal cells. And so the organism here we can say our animals, and this includes ourselves. Now, in terms of being a branch structure, we can say that glycogen is in fact, a branch structure, so we can say yes here and in fact, there are quite a lot of branches and each of the branch points are going to be linked via Alfa 16 Glick Acidic linkages. Just like Amul OPEC tins. Branch points were linked by Alfa 16 like acidic linkages. Now, speaking of comparisons, tow am alot pectin, you might notice that this table here resembles the same table from Amel, OPEC and quite a lot. And really, the Onley differences between the two table are the organism animals and then this word over here a lot. Other than that, everything else in this table is practically the same from am alot pectin recall am alot pectin instead of being found in an animal's Amla, pectin is found in plants and other than that in terms of structure, uh, glycogen has a lot more branching than Amel OPEC, Tim. And so we can say that glycogen is branch points are going to occur on average much more frequently than Amel OPEC tins, branch points And so you might recall from our previous lesson videos that amul OPEC tins. Branch points occur every 24 to 30 residues on average, whereas on average glycogen is branch points occur every 8 to 12 residues, and so that's much much more frequently and much more branching. And of course, the branch points are going to occur via Alfa 16 like ascetic linkages which is the same as the branch points from am alot pectin. And so really, what we can say is that glycogen is am alot pectin with just ah lot mawr branching. And so if we take a look at our image down below notice that this image here represents the structure of glycogen and what you'll note is that all of these red circles that we see down below including this one up here, represent branch points. And so, uh, there are, ah lot more branch points in glycogen structure than an amul Oh, pectin structure. And again, the branch points are going to occur at Alfa 1/6 like acidic linkages just like this one right here. And so all of these red circles represent Alfa 1/6 like acidic linkages. However, the vast majority of the glucose molecules that we see here here and pretty much everywhere else are going to be linked via Alfa 14 like ascetic linkages. And so what you'll note is over here on the right hand side we have another visual to help you distinguish between Angelo pectin and glycogen. And so one thing to note is that here, what we have is ah, bunch of glucose molecules. All of these blue balls represent glucose molecules. And so this represents the main chain right here. And notice that there are branches coming off of the main chain. And so this, because it has less branching, represents the structure of a Melo protectant. Now, notice Over here on the right. Uh, the main chain is right here and coming off our ah lot mawr branches and so the branches, because they're occurring more frequently. Uh, this is going to represent glycogen ins structure. And so you can see glycogen just has ah lot mawr branch points. And so, really, this here concludes our lesson on glycogen, and as we move forward, we'll be able to get some practice applying these concepts. So I'll see you guys in our next video

The storage form of carbohydrates in animals is:

• A. Glucose.
• B. Amylopectin.
• C. Lactose.
• D. Glycogen.

In glycogen there are:

• A. Alpha 1-4 glycosidic bonds only.
• B. Alpha 1-5 glycosidic bonds only.
• C. Alpha 1-6 glycosidic bonds only.
• D. Alpha 1-4 and 1-6 glycosidic bonds only.
• E. Alpha 1-4 and beta 1-4 glycosidic bonds.

all right. So in this video, we're going to review the poly sack rides that we've covered so far by completing the table down below. And so hopefully, by completing this table just a couple of times, you guys will be familiar with the most important features of each of these poly sack rides. And so, in our first row, we have cellulose, which is a homo polly sack ride of D glucose repeating sugars. And so these d glucose repeating sugars are going to be co violently linked to each other via beta 14 Glick ascetic linkages. Now, although this doesn't apply toe every Pollie Sacha, right that exists Notice that on our table all of the Glock acidic linkages that have beta configuration are going to have a structural function. And so you can think and associate beta with structural here for all of these poly sacha rides. And so, of course, we know that cellulose is going to be the primary structure of plant cell wall. So it's found in the plant organisms and in terms of being branched, cellulose is not branched. And so the next Polly Sacha, right that we have is chitin and chitin is also a homo Polly Sacha ride, but this time it's actually made up of nag sugars instead of D glucose sugars. And so recall nag just stands for n acetyl glucose, amine and all of these nags sugars are going to be co violently linked to each other via beta one forg like acidic linkages. And again, because it has been a configuration, it's gonna have a structural function. And we know from our previous lesson videos that chitin makes up the structures of hard exoskeleton shells and specific animals. And those animals include insects and crustaceans like lobsters or crabs and things of that sort. And in terms of being branched, chitin is also not branched. Now the next police accurate that we have is Pep Tito Glikin, which is actually the Onley hetero Polly Sacha ride on our list here. And so, of course, hetero means that it's gonna be made up of more than one repeating sugar unit. Eso notice that it's made of the nag, which is n acetyl glucosamine, just like kitten. But it also contains the nam sugar, which is n acetyl muir Amick acid. And so the nag and Nam uh sugar units are going to be co violently linked via beta 14 Glock acidic linkages. And again, the beta configuration reminds us that it's gonna have a structural function. And from our previous lesson videos, we know that Pep Tito Glide can makes up the structures of bacterial cell walls. And so, for the organism, we can write bacteria here and in terms of being branched, Pep Tito Glicken is not branched. So now, down below, What we have is starch and recall from our previous lesson videos that start has two forms am alos and am alot pectin. And so what? It helps me remember that Melo pectin uh, the only way that it differs from am alos is that it's branched is the pectin part. Kind of reminds me of pecking, and so if it's packing, then of course it's going to be branch because it's gonna have a bunch of little pecking spots on. So it's kind of silly, but it helps me, so hopefully it will help you guys, too. Now, in terms of starch, which applies for those animal Amla pectin, they're both homo Polly sack rides of D glucose residues, just like cellulose however, noticed that cellulose has beta 14 glad pathetic linkages whereas starches going tohave Alfa 14 Gleick ascetic linkages and the Alfa configuration here on our chart eyes going to be associated with energy storage function and so starts we know is gonna act as an energy storage molecule in plant cells. And of course, the only difference between AM a loose and amel OPEC in which we already mentioned is that am alos is not branched, just like all of these other ones up above. And Angelo Pectin is actually branch and the branch points occur at Alfa 16 Glick Ascetic linkages now, last but not least, down here. What we have is the poly Sacha ride glycogen and notice that glycogen is pretty much exactly the same here as am alot pectin on. Really the only difference is going to be here with the plants and then down here with the lots. And so what you'll note is that glycogen is a homo Polly sack right of d glucose linked by Alfa 14 Gleick acidic linkages. It has an energy storage function, but in animal cells such as ourselves and glycogen is going to be branched, however, it's gonna have a lot more branching than am alot pectin and the branch points are still going to occur. It Alfa 16 like acidic linkages. And so really, that's it. Our table is now complete, and there are a couple of patterns here that hopefully will help you guys when studying this chart. And so the first is with the type in terms of being Homo or hetero noticed that all of them on this list are Homo Polly sack rides. Except for Pep Tito Glicken. It's the only hetero one, and then, in terms of the repeating sugar unit, noticed that most of our repeating sugar units are going to be D glucose molecules and the only two that don't have d glucose molecules Arc Iten and Pep Tito Glikin. But notice that even with these, they both have nagged molecules. And the only difference here is the Nam. Now notice that with the blue color coordination, uh, that all of the ones with the blue background have beta 14 Gleick acidic linkages and are therefore structural, whereas the ones with the yellow background all have Alfa 14 Gleick acidic linkages and they're all energy storage. But something that's really convenient to note here is that they're all Glick acidic languages, regardless of their configuration. So a t least we don't need to remember to many other numbers unless it's gonna be the branch points. Of course, which occurred Alfa 16 on then, of course, the organisms are gonna be helpful to keep in mind, uh, from our previous lesson videos and in terms of being branched or not noticed that all of them are not branched. Um, pretty much all of them are not branch. And the only ones that are branched are am alot, pectin and glycogen. And so, again, hopefully by filling this table out from memory ah, couple of times, you guys will be able to remember the most important features of these poly sack rides. And so I will see you guys in our next video