Lecture 6: The Carbohydrates: Sugars, Starches, and Fibers**Note- Metabolism chapter will not be covered todayOutline of Last Lecture II. Digestiona. CHOb. Proteinc. Fatd. Muscular Action of DigestionIII. AbsorptionTransportOutline of Current Lecture Nutrition 2380II. Carbohydratesa. Chemist Viewb. Dietary SourcesIII. CHO Familya. Monosaccharidesb. Disaccharidesc. Lactose IntoleranceIV. Complex Carbohydratesa. Glycogenb. StarchCurrent LectureChapter 4The Carbohydrates: Sugars, Starches, and FibersThe Chemist’s View of Carbohydrates:These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Carbohydrares = Carbon, Hydrogen, and Oxygen atomsMacronutrients (along with proteins and fats)“A Call for a Low Carb Diet that Embraces Fat”Today, there are many low or no carb diets, but there are studies that show that people who eat more fat and “avoid carbs” lose more fat.... Think, where do carbs even come from?Dietary Sources of CHO:-Bread, pasta, etc (what people usually think of)-Vegetables-Legumes, dried beans, and peas-Nuts-Fruits-MilkPurpose of CHO:1. Provide energy2. Furnish other nutrients3. Add flavors to food4. Roughage (Gi Tract)The Cho Family:Simple-Monosaccharides (single sugars): Glucose, fructose, galuctoseDisaccharides (double sugars): Sucrose, lactose, maltoseComplex-StarchGlycogenFibers: Soluble or insoluble (in water)Monosaccharides: Glucose: Body’s chief energy sourceFructose: Sweetest, occurs naturally in fruits and honey. Added to soft drinks, ready to eat cereals, etc, in the form of high fructose corn syrupGalactose: Naturally found in milkDisaccharides:Sucrose (fructose + glucose):Body can also convert fructose to glucoseTable sugar1 tsp white sugar = 5 g CHO12 oz can soda = 8-12 tsp sugarWhat about an apple??Soluble fiber, some vitamins and it has natural sucrose in itMyth: “Honey is more nutritious and should be used in place in sugar.” NOLactose (galactose + glucose):Referred to as “milk sugar”Maltose (glucose + glucose):Occurs from breakdown of starchOccurs during fermentation that yields ETOH (alcohol breakdown)Found very little in food, barelyLactose Intolerance:Intestinal cells produce lactase, that help digest lactose. If your body doesn’t properly produce the lactase, your body won’t be able to digest it. --> colon undigestedThis is why people become very bloated and gassy (diarrhea) Also, abdominal discomfortLactase deficient (rare) both parents need to pass on the geneLactase activity declines with age... Older people are more likely to have itDiseases or treatments that damage microvilliGenetic Prevalence:High risk: S. Asians, Native Americans, African AmericansLow Risk: Caucasians, N. EuropeansWho do we manage being lactose intolerance?Dietary Changes!! Limit dairyMilk products are treated with lactase (enzyme)Lactase tablets or dropsYogurt, keifer: OKCheese: Lactose diminishes with age... The older the cheese, the betterComplex Carbohydrates:Glycogen: Limited amount in meatsNo plants, branched glucose chainsRole: Storage form of CHO in liver and muscleStarch: Found in plantsOccasionally branched glucose chains (amylopectin) or unbranched glucose chains (amylose)Role: Food source for the
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