Carbohydrates

in this video, we're going to do a quick review on carbohydrates. So recall that carbohydrates are also known as sacha rides and carbohydrates, or sugars that are made up of carbon, hydrogen and oxygen atoms, and a ratio of C N to H N, where there are certain number of water molecules hydrating a certain number of carbon atoms. And we can see that in the root of carbohydrates where carbo refers to the carbons and hydrates refers to the water molecules hydrating those carbons. And so, if we mathematically distribute this little and over here, we can rewrite this chemical formula as C N. H two n o n. Or there are double the amount of hydrogen atoms than there are either carbon or oxygen atoms. And this is relevant because the chemical formulas of carbohydrates can be written in either format, and it's important to be able to recognize this and so recall that mono sacha rides our, uh, the monomers of carbohydrates and so mono. Sacha rides tend to be water soluble white crystalline solids with a sweet taste, and that's exactly how we know our sugars to be and carbohydrates can be used for lots of different functions, but carbohydrates can serve as a primary short term energy source and pretty much every living organism. Now, mono sacha rides can be repetitive. Lee linked together to create a poly sacha ride polymer. So in our example below, What we'll see is that we have these mono sacha rides listed on the left over here. And these are mono sacha ride monomers and through a process, we can link these mono sacha ride monomers together Covalin tely to create a poly sacha ride polymer. And unlike nucleic acids and proteins, Polly sack rides do not have directionality and notice that the ending o S e on a word is indicative that it is a sugar so a glucose, fructose, sucrose, etcetera all end in OSC and they are all sugars and carbohydrates. And so, in the next video, what we're gonna do is talk about the mono sack ride itself, and more specifically, we'll talk about glucose. And so I'll see you guys in that video

So now that we've refreshed our memories that mono sacha rides are the monomers of carbohydrates and could be linked together to form Polly Sacha rides, we can talk about the mono sacha ride itself and most mono. Sacha Rides contains several hydroxy groups and recall that a hydroxyl group is a functional group that consists of an oxygen atom bounded to a hydrogen atom and because, uh, mono sack rides contains several hydroxyl groups. They're known as Polly Alcohol's, where an alcohol is a molecule that contains a hydroxyl group and recall that glucose has a chemical formula of C six, h 12 06 and glucose is a mono sacha ride. And it is actually the most abundant Heche sauce where heck so sends an OSC. So it's definitely a carbohydrate, and the hex part refers to the fact that it has six Carbons and glucose can be used by pretty much every living organism, either as a source of fuel or to build structures and glucose. Monomers can be linked together via what are known as glucose acidic bonds. So let's take a look at an example and down here, what we'll see is that we have a glucose molecule. What? The chemical formula C six, H 12 06 and glucose could take two different forms. It can take a linear form or a cyclic form. And in both forms, what we'll see is that we have all of these hydroxyl groups, and therefore it is a poly alcohol and glucose. Monomers can be linked together via Glick acidic bonds, and we can see that over here, where each of these pink bonds represent a Glick acidic bond that links one glucose monos, aka ride to the next. And so when we link mono sack rides in this fashion, we create a poly sacha ride, and that transitions us perfectly into our next video, where we're going to talk about different types of Polly Sacha rides.

so examples of Polly Sacha rides includes starch, glycogen, cellulose, pep, Tito, glikin and kitten and all of these Air Polly Sacha rides that vary in their functions. And we'll talk about their functions down in the chart below. Now. Carbohydrates are quite interesting because they could be co violently linked to other macro molecules, such as proteins to create glycoprotein lipids to create like a lipids and nucleic acids to create nucleotides. And so, down here in our chart, what we're gonna do is fill in the function of each Polly Sacha ride that's listed in the left hand column and so recall that starch is used as energy storage and plants, whereas glycogen is used as energy storage and animals. Now you may have learned that cellulose is a predominant component off plant cell walls where, as pep Tito Glick hand as a predominant component of bacterial cell walls and Titan is used to create the hard shells of, uh, insects as well as crabs. And it's a predominant component in the cell wall off fungi. And so what you can see is that we have different structural Polly Sacha rides that have similar functions, but in different organisms, and you can also see that the first two are energy storage Polly Sack rides, whereas the bottom three arm or so structural Polly sack rides. And so over here on the right side image. What we have is a glycoprotein, and the glycoprotein consists of a carbohydrate portions shown in gray and a protein portions shown in light blue. And this carbohydrate portion has a chain and a secondary chain that branches off of the chain and carbohydrates tend to make these complex structures with lots of branching, and, uh, they don't have to, but they can. And so the glycoprotein here consists of the carbohydrate as well as the protein portion. Now in a similar fashion, we have a Glick, a lipid over here, which contains a carbohydrate portion and gray, and it also includes the phosphor, a lipid itself now down below. We have a DNA nucleotide, and what we can see is that it has a pento sugar, specifically a D, oxy, ribose, pento sugar and so carbohydrates or thes pento sugars. Here are an important component of all nucleotides and therefore a very crucial component to all nucleic acids, and so we'll talk a lot more about carbohydrates as we move forward in our biochemistry course, and I'll see you guys in the practice problem videos.

Which of the following expresses the correct chemical formula of a carbohydrate?

• A. C₆H₁₄O₅
• B. C₅H₁₀O₅
• C. C₄H₁₀O₆
• D. C₆H₁₂O₅