so let's start with carbohydrates carbohydrates are made up of simple sugars and we call these simple sugars mono saccharides so a monosaccharide is a simple sugar and most all simple sugars contain between five and six carbons some have a few more a few less but typically the ones we'll look at contain five or six carbons and one of the most ubiquitous is going to be glucose and glucose also we have some other ones like fructose glucose can combine with fructose to form a dimer or a disaccharide and this is what we find in table sugar so let's look at the structure of glucose and then we can talk a little bit about its properties so here's glucose and you immediately notice that there's a lot of oxygen in it glucose has six carbons six oxygens and 12 hydrogen's in fact if you look at carbohydrates in general they have a carbon to hydrogen to oxygen ratio of one to two to one so our glucose has six carbons 12 hydrogen's and six oxygens so we did it here adheres to this ratio and we can see that these oxygens are covalently bonded to carbon and two hydrogen so what does that mean that means that this is a polar molecule it has polar covalent bonds and polar covalent bonds like water so sugar can interact with water so if you've ever dissolved table sugar and water you know that it dissolves completely so what we will see is that this sugar molecule will be completely surrounded by water so the positive end of water will be oriented toward the negative end of this polar molecule so this oxygen so this creates what we call a hydration sphere and so just like sodium and chloride ion are dissolved in water so we'll individual molecules of sugar be dissolved in water because water will form a hydration sphere around each individual molecule sugar so that now the sugar is floating around in the water now let's talk about solutions a solution is a uniform mixture of two or more substances the liquid part of the solution and most of the solutions we will be talking about are liquid there are some gas solutions but will not be discussing them in here liquid solutions contain a solvent which is the thing that is doing the dissolving in this case it would be water almost all the solutions that we'll be dealing with in biology and in this class will be water based so the solvent will be water and the thing that is dissolved is the solute so in this case our solute is the sugar and so when you have a solvent dissolving a solute you get a solution so this is one of the properties of sugar because it has all of these oxygens in it it is polar and therefore can interact with water now let's take this molecule and let's abbreviate it so we can write shorthand for sugar so I'll write a shorthand for glucose where we simply denote a ring that has an oxygen over here in one of these corners so this is understood for glucose and so we can link one glucose to another simple sugar it could be fructose it could be another glucose and we'll denote a linkage between the two glucose molecules like this with an oxygen in here and now we have a disaccharide because we have no linked to simple sugars or monosaccharides together to create a disaccharide we could keep linking glucose molecules together we could form glycogen in such a way and we would have a poly saccharide so basically we can consider a sugar a chain of sugars as a polymer so a polymer is a chain of things that are stuck together things that have similar nature so if we stick a monosaccharide together with another monosaccharide we have formed a disaccharide and if we keep on sticking monosaccharides on here we will get a chain of monosaccharides that is a polysaccharide and more generically speaking the polysaccharide is a type of polymer where mer just stands for a single unit of something and so sugars can build starches we can build starch out of simple sugars just by linking them together and glycogen which is sometimes referred to as animal starch that is found in abundance in human skeletal muscle and liver glycogen is a method of storing energy so carbohydrates are very good at being broken down for energy