Exam 2 Study Guide 1 HUNGER AND APPETITE a Hunger physiological drive for food that is nonspecific and can be satisfied by a variety of foods b Appetite psychological desire to consume specific foods and is aroused by the environment 2 INTESTINAL TRACT DIGESTION ABSORPTION AND ELIMINATION OF FOOD Digestion large food broken down into smaller molecules mechanically and chemically a b Absorption process of taking in products through intestinal wall across a cell membrane into cells of the body small amounts occur in stomach and large intestine the most occurs in the small intestine Elimination undigested portions of food and waste are eliminated from the body c d Organs of the GI tract mouth pharynx esophagus stomach small and large intestine and rectum e Enzymes manufactured held and stored by the pancreas i Amylase digests carbs ii Lipase digests fats iii Protease digests proteins f H and hormones of digestion i Gastrin secretin CCK CIP ii Potential digestive roles somatostatin ghrelin g Aaccessory organs that facilitate digestion i Salivary glands ii Liver synthesizes chemicals for metabolism Releases glucose from glycogen stores filters blood iii Gallbladder stores bile signaled by CCK to release bile which emulsifies lipids iv Pancreas see enzymes stores inactive enzymes FOOD INTOLERANCE VS FOOD ALLERGY 3 4 a Lactose intolerance insufficient enzyme lactase to digest the lactose containing foods Symptoms gas cramping diarrhea Not to be confused with milk allergy Need to alternate sources of calciumDefine lactose intolerance 5 CARBOHYDRATE METABOLISM a Simple carbohydrates i Contain one or two molecules ii Commonly referred to as sugars b Monosaccharides contain one molecule i Glucose fructose and galactose c Disaccharides contain two molecules i Lactose maltose and sucrose 1 d e Complex carbs i Oligosaccharides have 3 10 monosaccharides ii Most polysaccharides consist of hundreds to thousands of glucose molecules f Carb digestion all monosaccharides are converted to glucose by the liver Glucose circulating in the blood is our primary energy source Excess glucose is stored as glycogen in the liver and muscles i DOES NOT occur in the stomach MOST occurs in small intestine ii Salivary amylase begins digestion in the mouth and carbs are broken down to maltose Stomach acids inactivate salivary amylase g hormones regulating blood glucose i insulin secreted by beta cells of the pancreas ii glucagon secreted by alpha cells of the pancreas stimulate gluconeogenesis the production of glucose from amino acids iii Epinephrine and norepinephrine secreted by the adrenal glands and nerve endings when blood glucose is low Increases glycogen breakdown in the 2 h glycemic index liver releasing glucose into the blood Responsible for fight or flight reactions to danger iv Cortisol and growth hormone secreted by the adrenal glands to act on liver muscle and adipose tissue Cortisol increases gluconeogenesis and decreases muscle glucose use Growth hormone decreases muscle glucose uptake increases fatty acid mobilization and increases liver glucose output i a food s potential to raise blood glucose Foods with high glycemic index cause a sudden surge in blood glucose Higher insulin lower blood glucose ii Foods with a low glycemic index cause low to moderate fluctuations in blood glucose 1 Reduce risk for heart disease and colon cancer 2 High fiber intakes help improve fat levels in the blood higher HDL i and glycemic load and lower LDL i Determines the effect of a food on a person s glucose response ii Grams of carbs in a food are multiplied by the glycemic index j Ketosis fat breakdown during fasting forms ketones Excess ketones increase blood acidity and cause ketoacidosis source i Sufficient energy from carbs prevents ketone production as alternate energy k ketoacidosis and gluconeogenesis occurs when a diet is deficient in carbs i The body will make its own glucose from protein ii Amino acids from these proteins can NOT be used to make new cells repair tissue damage support the immune system or perform any of their other functions l Diabetes inability to regulate blood glucose levels i T type 1 accounts for 10 of all cases 1 Body does not produce enough insulin 2 Causes hyperglycemia high blood glucose 3 Requires insulin injections 4 May be an autoimmune disease ii and Ttype 2 insulin insensitivity resistance cells become less responsive to insulin type 2 1 Metabolic syndrome a cluster of risk factors than increase risk for 2 Increasing in children and adolscents 3 Causes genetics obesity and physical inactivity 4 Treat with weight loss exercise and medications 5 Hypoglycemia low blood glucose may cause shakiness sweating anxiety weakness 3 a Reactive pancreas secretes too much insulin after a high carb meal b Fasting pancreas produces too much insulin even when someone has not eaten c diabetes 6 FAT METABOLISM happen 7 After absorption what are the possible fates of triglycerides How do each of these fates 8 Know the different classification of carbs fats and proteins and how they can be stored or utilized in the body 9 What are the characteristics properties of saturated fatty acids versus unsaturated fatty Saturated fatty acids hydrogen atoms surrounding every carbon in the chain acids a b Monounsaturated 1 double bond lack one hydrogen atom c d Shape Polyunsaturated more than 1 double bond i Saturated shape packed tightly together solid at room temp animal fats butter and lard ii Unsaturated shape don t stake well together liquid at room temp hydrogen atoms can be arranged in different positions 1 Cis same side of the carbon chain 2 Trans opposite sides of the chain 10 Know what the relationship is between trans fatty acids and hydrogenation 11 a Hydrogenation hydrogen atoms are added to unsaturated fatty acids i Make oils more solid and more saturated ii Create trans fatty acids iii Reduce oxidation resist rancidity Increased risk of cardiovascular disease iv 12 What is the process of digestion of lipids 4 a Digestion of Fats begins in small intestine i CCK and secretin gallbladder contractions release bile 1 Bile emulsifies fat into small droplets produced by liver and stored in the gallbladder ii Pancreatic enzymes break fat into 2 fatty acids and a monoglyceride 13 Know essentially fatty acids and their sources a Essential fatty acids cannot be made by the body and must be obtained from food i Linoleic acid omega 6 fatty acid found in vegetable and nut oils 1 Fish and fish oil EPA DHA 2
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