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Published byMaryann Weaver Modified over 8 years ago
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“Carbohydrates” Do you ever: Think of carbs as providing nothing but calories to the body? Wonder why nutrition authorities recommend foods high in fiber? Blame carbs for obesity or disease? Have trouble distinguishing whole- grain foods from others at the store?
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What are some foods rich in carbs?
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Where do we get them? “Green plants make carbohydrate through photosynthesis.” In this process, water, sunlight energy, and oxygen are used. “Light energy is stored in a plant as chemical energy: carbs.” The purpose is to store energy for later (when it’s dark).
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Photosynthesis
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“Milk: the only animal-made food with lots of carbs, to supply baby with energy” For this reason, breastfeeding mothers need to eat a lot….they burn up to 500 calories a day just feeding!
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Let’s Look at the Molecules “Six sugars are important to us.” “Three: Monosaccharides, single sugars” “Three: Disaccharides, double sugars” They all end in –ose, which means sugar.
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“The three mono’s join together in combinations to make the three di’s.”
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A note on the glucose symbol: The glucose molecule is really a ring of 5 Carbons and 1 oxygen plus a carbon “flag.” Carbons Oxygen For convenience, glucose is symbolized as or
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“Mono’s” “1. Glucose: most common, used by plants and animals. AKA blood sugar.”
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“2. Fructose: in fruit, honey, added to prepared food (high fructose corn syrup).”
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“3. Galactose: is a part of milk sugar (lactose)” This is rarely found in nature on its own.
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“Di’s” “All contain glucose” “1. Lactose: milk sugar”
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“2. Maltose: appears where starch is being broken down (ex. stomach)”
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“3. Sucrose: table sugar, found in plants” Where does your table sugar come from?
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Table sugar is usually obtained by refining the juice from sugar beets or sugarcane. Discovery Streaming Discovery Streaming Discovery Streaming
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Eating fruit is different from eating candy because the molecules are different. Fructose is a monosaccharide, which is digested differently than a disaccharide. Both contain sugar, but the body views them very differently!
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Which brings us to… “Starch” What kinds of foods do you think of when you think of starch?
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“Plants put glucose into long strands for storage = polysaccharides.” “Starch and fiber are examples.” So starch doesn’t taste sweet, but it is made of sugar.
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For this reason, fresher corn tastes sweeter! Longer it sits on the shelf more sugar is stored as starch.
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Starch is useful to a plant when there’s no sunlight to obtain energy. It’s also helpful to seeds, which can’t photosynthesize. Plants pack their embryos in starchy seeds for a food supply.
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How do we store sugar? “Animals store sugar as glycogen in our muscles.” So why doesn’t a hamburger taste sweet? Glycogen breaks down quickly when an animal is slaughtered.
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“Fiber” Fiber is a super-important polysaccharide for us. “Fibers form the supporting structures of leaves, stems, and seeds.”
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Here’s the Catch… “We can’t digest fiber!!” So if we need it, but we can’t digest it, how do we get it?? “Soluble fibers easily dissolve in water, are digested by bacteria in our colon.” Good bacteria! We need it!
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Can anyone digest fiber? Animals with larger digestive systems (like cows) can digest fiber…it has to be digested repeatedly. When we eat the meat, we obtain the energy, but not the fiber.
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Soluble fibers dissolve in water and are digested by bacteria. These are excellent for us! “Oats, barley, and citrus: lower cholesterol, protect against heart disease and diabetes” They also add a nice consistency to foods, like fruit pectin that makes jelly thick and others that thicken salad dressings.
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“Insoluble fibers don’t dissolve in water, and help us eliminate waste.” Patients who are chronically constipated usually don’t have enough fiber or water in their diet. “Bran, celery, corn, seeds” We now know: very good at preventing colon cancers!
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