 Hi everybody, Dr. O here. So we've covered the monosaccharides, which are single saccharides or single sugar units. We've covered the disaccharides, which are pairs. Now we're looking at the polysaccharides. So poly means many. So polysaccharides are going to be long chains of the monosaccharide glucose. So all you're seeing here is glucose. There's no longer any galactose or fructose. These can be either from a few to a thousand or more glucose units long. The three kind of polysaccharides we talk about are going to be starch, glycogen and cellulosis. So a quick overview, starch is how plants store carb energy. Glycogen is how animals like humans store carb energy and cellulose or fiber is going to be your undigestible or indigestible carbohydrates or polysaccharides. So let's dive in here and look at all three. So starch, so starch again is how we get, we get a lot of our energies from carbohydrates come from starch. These are plant-based. So plants are storing carbohydrates in the form of starch and then we can eat it and digest it and break it down. So starches are polymers of glucose, but you'll notice there's two different types. We have amylose and amylopectin. So later on when we talk about digestion you'll see that the amylases are the enzymes that break down carbs and that makes sense when you see the terminology here. But amyloses are going to be straight chains of glucose. Amylopectin are going to be branched chains of glucose. Reason this matters is because they're going to have a different impact on blood drinking control. So the biochemistry, you know, does matter. An amylose chain, when the enzymes come to break this chain down into individual glucoses it only can eat or digest from both ends. But look at that amylopectin. There's what, 10 or so, excuse me my nose is itching, there's either 10 or so areas where they can cleave off a glucose and go ahead and use it. So if you consume a food that's really high in amylopectin you'll probably get a quicker rise in your blood sugar than if you consume a carbohydrate full of amylose. And that's one of the reasons that different high-carb foods have unique or different glycemic indexes or the amount of glucose, the response from consuming them. So that's going to be the amyloses and amylopectins, your starch, how plants store carbohydrates. Glycogen is branched just like an amylopectin and this is going to be how animals including humans store glucose. We store this in two key places, you store it, glucose is converted to glycogen and stored there in the muscles and the liver. So key difference, muscle glycogen is used for the muscles. So it's that saved up energy that muscle is going to use. Liver glycogen is stored in your liver to keep your blood sugar stable. Think about it. At 6 o'clock at night, you don't eat breakfast until 8 in the morning. What you just went, what you go 14 hours without eating. The reason that your blood sugar doesn't plummet is because your body will release this stored glycogen as glucose to keep your blood sugar elevated. So remember that muscle glycogen, think fuel for muscles. Liver glycogen, think keeping your blood sugar elevated when you go long periods without eating. All right. So that's going to be glycogen. Then lastly, we have cellulose or fiber. So the key thing here, this is a polysaccharide, it's made of pure glucose. But the reason it doesn't have this huge glucose response or sugar response and the reason we don't get a lot of calories from it is because those bonds right there in the middle. So your body can cleave those individual glucosees, but we can't break those cross-lingages, those bonds. We don't have the enzymes to do so. So that's why fiber is considered an undigestible or non-digestible polysaccharide. So it's the structural material of plant cells. We call it fibers, a good word for it. We cannot digest fiber, but there is, you do get a few calories. I find this very interesting. So people always say that fiber doesn't have any calories, but we get about one calorie from every gram of fiber we eat, but we get it from fat. And that's because these fibers, we can't digest them and break them down, but many of the microbes living in us can. Right? That's why we have, and I'll cover the types of fiber in a separate video, but we have your roughage, that fiber that just passes through you. That's known as insoluble fiber. Soluble fiber is fermentable. So the microbes that live inside of you can ferment that fiber. And as they do so, they produce short-chain fats that you can actually absorb and use for fuel. It's the primary fuel of the cells of your large intestine, the cells of your colon, butyrate being the most important short-chain fat. This is the same thing with ruminant animals like cows, I'm fascinated by them. They just eat and eat and eat fiber, but they live on short-chain fats because the microbes living in those rumens convert that fiber into short-chain fats that they absorb and they use for fuel. Pretty cool. You can see fiber doesn't have vitamins and minerals, it doesn't have much caloric value, but there are health benefits to a diet high in fiber. Number one, it might help you stay full longer. The roughage, it kind of helps keep them getting constipated, keeps food moving. High fiber diets have been shown to decrease heart disease primarily by lowering cholesterol, and that's because fiber binds to things. So your body dumps bile into your intestines and reabsorbs most of it. Bile is full of cholesterol. So if you're eating a high fiber diet, that bile gets dumped into your intestines, gets swept through by fiber and isn't reabsorbed. So your body has to make new bile, and to do so it uses new cholesterol. So that's the reason we think that high fiber diets will lower your cholesterol. High fiber diets probably decrease your risk of cancer, I'd say colon cancer would be the most probable there. And then for me, I also teach microbiology, the number one reason to consume a high fiber diet is because of that fermentation, it feeds the good microbes living in your microbiome of your gut. I tell students in microbiology the number one thing you can do for your health is make sure you're consuming at least six grams of soluble or fermentable fiber a day. That's kind of my thing. All right. So those are your polysaccharides. I hope this helps. Have a wonderful day. Be blessed.