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Organic Chemistry

Learn the toughest concepts covered in Organic Chemistry with step-by-step video tutorials and practice problems by world-class tutors.

Table of contents
24. Carbohydrates

Monosaccharides - Common Structures

Pentoses and hexoses are highly prevalent in biological systems. You probably only need to know a few of these. Let's learn some tricks to make them easy to remember & draw out. 


Monosaccharides - Common Structures

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Now I want to show you guys some easy ways to memorize the structures of a few of the important mono sack rights. So guys in biology, penthouses and heck sauces are really highly prevalent. And you probably need to know a few of these, but you probably also don't need to know all of them. So, for example, guys, for the hex doses there are so many. They're like 16 different hex doses with all common names that are different from each other. There are lots of Penn Tose isas. Well, this section is going to depend on your professor. Your professor may want you to memorize all the Aldo heck sources, in which case this video is not gonna help you very much. But most of the time, professors don't care that much about the exact names, and they just want you to be familiar with the most important structures. So that's what I'm going to try to do here. I'm gonna try to summarize just some of the most important structures and give you guys easy ways to memorize them. So just you guys know, first of all, biological systems tend to recognize de mano Sacha rides more than El Mono sack rides. So all the structure we're gonna talk about pretty much for the rest of the section are gonna be D sugars. Okay, We're not going to talk about l sugars anymore because they're not really used. Ah, lot in biology. Okay. Eso really? Um, one of the most important Pento says that you need to know is ribose. So what I did was I took out all the o. H. Is and all the hs that we could write them in together as we memorize it. Okay, So d ribose would obviously have the last ohh facing towards the right because it's a D. But then where did the other ohh is face. Well, this one is easy because it has a nickname. Or like a little saying. What you can say is that ribose is all right. And what that means is that all the O. H. Is are to the right. Okay, Rivals is a very important Prentice Pintos because it's the backbone for DNA and RNA. Remember, it's called deoxyribonucleic rival nucleic acids. So it's made out of a ripe Oh, so you need to know about ribose and then the other side would just be ages. So ribose is all right? Easy enough, right? Cool. All right, so now let's talk about glucose. Come on. Glucose is super important. How do you draw glucose? Well, we know that a D Glucose would have the last A wage facing to the right. But then where did the other three go? Okay, well, guys, this one's a little bit of scene, so I'm not going to do it on camera. But this is one of the ways that I found online that most students remember glucose. So go ahead and take your hand. Take your right hand and put it in front of you. I'm gonna do this off the camera and make a fist, so make a fist like this. Now, go ahead and flick yourself off. Okay? If you guys saw it right, you guys saw a little bit of, uh of my hand. Come up now, look down at that and notice that that's actually gonna show you your positions. That's gonna show you your 23 four and five positions where you're you're the finger that's being very rude to you right now is one of the O h is so glucose guys, it flicks you off, so it's gonna look like this. Ohh ohh And ohh! Those air your four fingers being represented by glucose giving you the big middle finger. Okay, And that's what it's telling you right around holiday season. Or, you know, when you're going to go out and splurge on sweets, it's saying, Hey, you're going to regret this later. So the H is we're just going opposite places. Cool. Eso guys, those air ribose and glucose Super important. But there are others that come up pretty often as well. And thankfully, these can just be thought of as, um related to the other ones that we learned especially glucose. So manos we've already dealt with it earlier. De Manos is just the C two ep immer of glucose. So we're going to draw glucose again. Remember that it had the O h the O h b O h. But the C two FM Marines that one position switched. So then I would put this Ohh! Over here that would be de manos dig a lactose would be the C four ep immer of glucose. So that means I'm going to draw all the other positions exactly the same. Remember, this one's flipping me off over here, but now, in this case, I'm gonna actually get guess I'm gonna get flipped off by two fingers in the middle here, so that would be the C four FM er is galactus h h h h. And then finally, I'm gonna I'll take myself out of the screen here, and what you're gonna see is that d fructose fructose is very important. But it's a key toes, and it's actually gonna be the key toast of glucose. So think about that. This was a glucose that's drawing all of the different O. H. Is that you would expect for glucose H h h. But then remember, guys that key toeses need to form on that second carbon in order to qualify as a key tone. Right? So that means that this one here just becomes a key tone, and this would be called D fructose, which is a six carbon key toast. Okay, Specifically, it's the fruit. It's the key toast of glucose. OK, now, guys, once again, I don't know exactly your professor wants This might be more than your professor wants. Your professor might not want you to memorize a lot of structures, or they might want you to memorize a ton. I'm just trying to help you with the most important ones. And if you need to know more than this, then I would. There's there's more that other videos that might be able to help you. Okay, this is just like a basic overview of the most important ones. And hopefully you found this helpful. All right, so let's move on.