Quiz Study Guide 2 6 CARBOHYDRATES Cx H2O y o Example C6H12O6 o 6CO2 6H2O energy C6H12O6 6O2 Photosynthesis creates carbs RDA 130 grams day to provide enough glucose for your brain prevent ketosis AMDR 45 65 Daily Value 300 grams day 60 of 2000 kcal day Dietary Carbohydrate Family o Simple Carbohydrates Monosaccharides hexoses Fructose intense sweetness Glucose mildly sweet Galactose barely sweet Formed by condensation makes H2O Disaccharides Broken by hydrolysis uses H2O Glucose Fructose Sucrose Glucose Galactose Lactose Glucose Glucose Maltose o Complex Carbohydrates Polysaccharides Glycogen Starch Fiber Starch o Storage form of energy in plants o Main sources grains legumes tubers o Glucose molecules linked through condensation reactions Amylose long unbranched chains Amylopectin branched chains Glycogen o Storage form of energy in animals o Not considered dietary carb o Long highly branched glucose chains Highly branched is an advantage have to attack from the end of the chain so it would be a slow process if it wasn t branched but because it is the glucose can be attacked at multiple places at once o Storage capabilities Major storage sites Liver Uses glycogen to regulate blood glucose levels 1 3 Skeletal muscle Glucose reservoir for strenuous muscle activity 2 3 Bacteria in your mouth feed on carbohydrates Bacteria produce an acid that kills tooth enamel To reduce risk eat with other foods lower exposure time Body storage capacity 200 500 grams Fiber o AI 14 grams 1000 kcal consumed o Daily Value 25 grams o Structural part of plants o Indigestible Consume with water Fiber has beta linkages and our body doesn t have digestive enzymes that can digest beta linkages but the bacteria in your GI tract can ferment fiber and turn them into energy Still not considered energy yielding o 1 Soluble Fiber Easily fermentable Dissolves in water to form a gel your stomach Delays stomach emptying Gel is viscous and easily fermentable by the bacteria in Gives you that feeling of fullness and helps you feel fuller longer until your next meal Helps with weight management and obesity Good for diabetes much slower entry of glucose into the bloodstream Slows food transit through small intestine More nutrients can be absorbed Cholesterol lowering Decreases risk of coronary heart disease CHD o 2 Insoluble Fiber Not easily fermentable Commonly found in vegetables whole grains Absorbs water and increases bulk Benefits Increases GI motility reducing transit time through colon Alleviates constipation Lowers risk of diverticulosis and hemorrhoids Promotes colon health Digestion o Mouth salivary amylase o Stomach digestion stops effects of fiber occur o Small Intestine Pancreatic amylase breaks down starch into small polysaccharides sucrase maltase lactase disaccharidases break down disaccharides o Large intestine fiber resistant starches attract water softening stool Absorption o Travel to the liver via portal vein o Active transport glucose galactose o Facilitated diffusion fructose o Galactose fructose are metabolized or converted to glucose sent to organs that need it e g brain o Glucose mostly released into the bloodstream for use by cells Why beans produce gas beans contain 2 oligosaccharides 2 10 chain polysaccharides and your body cannot digest them so they go right into the LI undigested and they attract water and the bacteria start to ferment them and they create gas Lactose intolerance o Lactase activity decreases with age o Linked to genetics Linked to ethnic groups o Dietary changes Manage dietary intake Spread it throughout the day Combine with other foods Lactaid enzyme droplets Glucose in the Body o Provide energy o Preferred fuel for the brain developing red blood cells and the nervous system o Protein sparing gluconeogenesis when carbs aren t available o Fat metabolism o Ketone bodies o Regulating blood glucose levels Insulin response to elevated levels Increases glucose uptake by cells Simulates glycogen production in liver and muscle Stimulates conversion of extra glucose to fat Glucagon response to low levels Stimulates liver cells to break down glycogen Stimulates gluconeogenesis from protein in liver Epinephrine also stimulates the breakdown of glycogen Glycemic Index GI affected by type of carb cooking method and presence of fat dietary fiber o Low GI diet benefits Decrease risk of developing type 2 diabetes Improve blood sugar control of diabetics Weight loss Evidence shows that glycemic index is not associated with body weight and doesn t lead to greater weight loss Health Issues o Sugar Dental Caries Nutrient Intake Replaces foods rich in other nutrients If excess calories contributes to obesity o Dietary Fiber Lower risk for CHD cholesterol specifically soluble fiber Takes bile so that the liver takes more bile using cholesterol lowers blood cholesterol levels Helps slow gastric emptying so that there aren t surges in blood glucose levels Promotes GI Health and Functioning Insoluble fiber absorbs water softer stools eases pressure no constipation lower risk of diverticulitis lower risk of hemorrhoids and it s important for the GI muscle health Diabetes Obesity People with high fiber diets tend to weigh less than those with low fiber diets o Because high fiber diets tend to be low in fat and o low in calories If you feel full you generally eat less because you feel full faster and longer Cancer no details 7 LIPIDS Dietary Guidelines recommendations o Saturated fat 10 o Trans fat as little as possible o Cholesterol 300 mg o AMDR 20 35 Essential nutrient Organic Compounds o Triglycerides 95 dietary lipids fats and oils Storage form of fat in adipose tissue o Phospholipids 2 dietary lipids plant animal origin Major constituent of cell membranes o Sterols e g cholesterol Precursor of sex hormones adrenal hormones vitamin D and bile Fatty Acids 4 24 carbons o Short chain 6 o Medium chain 6 10 o Long chain 12 o Essential Fatty Acids Linolenic Acid 3 C18 3 Sources of ALA Soybean oil canola oil flaxseed oil walnuts EPA DHA made by elongation and de saturation cold water fatty fish Expands blood vessels Inhibits blood clotting Doesn t cause inflammation All associated with preventing coronary heart disease Linoleic Acid 6 C18 2 Sources seeds nuts vegetable oils Constricts blood vessels Promotes blood clotting Promotes inflammation All associated with coronary heart disease Saturated Unsaturated o Degree of saturation affects stability o Saturated No double bonds Solid at room