ProteinSu 08 slide pdf - Carbohydrates Carbohydrate...

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Unformatted text preview: Carbohydrates Carbohydrate Factoids Macronutrient Carbon, oxygen, hydrogen Carbon-hydrate: C + H2O CarbonCHO Glucose: C6H12 O6 1 CHO functions Provide energy Spare protein Provide fiber Provide sweetness CHO Types Simple Mono- and di-saccharides Monodi- Complex Polysaccharides Figure 4.2 2 Figure 4.3 Relative Sweetness Sucrose = 1 Lactose = 0.2 Maltose = 0.4 Glucose = 0.7 Fructose = 1.5 Common Sweeteners White and brown sugar Molasses High fructose corn syrup Honey Fruit sweeteners Raw sugar 3 Figure 4.4 Lactose Intolerance What Who Why Symptoms Cause of symptoms Improving tolerance Intermediate sized CHO Raffinose Stachyose Indigestible molecular bonds Food sources 4 Complex Carbohydrates Starch Polysaccharide Plant storage form of CHO/energy Digestible alpha bonds Figure 4.5 Dietary Fiber Indigestible polysaccharides Beta bonds Types Insoluble fiber Soluble fiber 5 Soluble and Insoluble Fiber Food sources of complex CHO Starch Some fruits and vegetables Grains Tubers Legumes Fiber Insoluble Whole grains/bran Vegetables Soluble (viscous) Fruit Oats Legumes 25-38gm/day 25- Unprocessed vs Processed Fresh fruits and vegetables Whole grains Bread, cereal, rice White bread Soda/soft drinks Cookies, cakes Added sugars, jam Legumes 6 Are high-carbohydrate diets healthy diets? Comparison of CHO Sources 50 gm CHO: Calories Fullness Fiber Vit/Min Vit/Min Coke 200 little none ~0 w/w bread 200 bulky 6-8 gm ++ Orange juice 200 little none ++ Whole orange 200 bulky 6-8 gm ++ Glycemic Index (GI) Definition: A rating of the potential of a food to raise blood glucose and insulin levels Determinants of a food's GI Mixed meals vs single foods Caveats and pitfalls Potential usefulness 7 Figure 4.9 Enterohepatic Circulation In the gallbladder, bile is stored In the liver, bile is made from cholesterol In the small intestine, bile emulsifies fats Bile reabsorbed into the blood In the colon, bile that has been trapped by viscous fibers is lost in feces This cycle is called the enterohepatic circulation of bile. Some bile is excreted. enteron intestine hepat liver Health benefits of minimally processed carbohydrate foods 8 Disaccharide Digestive Enzymes Brush border enzymes Sucrase Maltase Lactase Hydrolysis of a Disaccharide Hydrolysis: Water HOH Bond broken Maltose Glucose + glucose Occurs as plant food is digested. v b Body Carbohydrate Simple blood glucose Complex glycogen 9 Blood Glucose Blood sugar Circulating fuel (5 gm) Brain and central nervous system Glycogen and Starch Molecules Compared (Small Segments) Complex CHO Glycogen Body CHO Starch (amylopectin) Plant CHO Starch (amylose) Plant CHO Figure 4.7 10 Figure 4.10 BG Homeostasis Homeostasis Hormone Insulin Anabolic/anabolism Glucagon Catabolic/catabolism Maintaining Blood Glucose Homeostasis 1 Intestine 2 Insulin When a person eats, blood glucose rises. High blood glucose stimulates the pancreas to release insulin. Insulin stimulates the uptake of glucose into cells and storage as glycogen in the liver and muscles. Insulin also stimulates the conversion of excess glucose into fat for storage. Pancreas 3 Liver Fat cell 4 Pancreas 5 6 Muscle As the body's cells use glucose, blood levels decline. Glucagon Low blood glucose stimulates the pancreas to release glucagon into the bloodstream. Glucagon stimulates liver cells to break down glycogen and release glucose into the blood.a Key: Glucose Insulin Glucagon Glycogen Liver 7 Blood glucose begins to rise. a The stress hormone epinephrine and other hormones also bring glucose out of storage. 11 Diabetes: Type 1 Who Why Treatment Risk factors Diabetes: Type 2 Who: adults, increasingly teens Why: insulin resistance Treatment: diet, exercise, medication Diabetes: Type 2 Risk factors Genetics Ethnicity Age Obesity Inactivity Which can be controlled? 12 Figure 4.16 Table 4.8 Diabetes: Long term consequences Damage to large blood vessels Atherosclerosis Damage to small blood vessels Eyes blindness Kidneys kidney failure Nerve tissue amputations 13 Know your risk factors. Control your risk factors! Artificial Sweeteners Types Safety Usefulness 14 ...
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This note was uploaded on 07/23/2008 for the course NUTRI SCI 1 taught by Professor Mead during the Summer '07 term at University of California, Berkeley.

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