Chapter Lecture Chapter 4: Carbohydrates: Plant-Derived Energy Nutrients © 2017 Pearson Education, Inc What Are Carbohydrates? • • • • • One of the three macronutrients Important source of energy for all cells Preferred energy source for nerve cells Composed of carbon, hydrogen, oxygen Good sources: fruits, vegetables, grains © 2017 Pearson Education, Inc What Are Carbohydrates? • Glucose • • © 2017 Pearson Education, Inc The most abundant carbohydrate Produced by plants through photosynthesis © 2017 Pearson Education, Inc What Are Carbohydrates? • Simple carbohydrates • • • • Contain one or two molecules Commonly referred to as sugars Monosaccharides contain one molecule • • Referred to as sugars Glucose, fructose, galactose, and ribose Disaccharides contain two molecules â 2017 Pearson Education, Inc Lactose, maltose, and sucrose © 2017 Pearson Education, Inc © 2017 Pearson Education, Inc What Are Carbohydrates? • Complex carbohydrates â 2017 Pearson Education, Inc Oligosaccharides contain to 10 monosaccharides Most polysaccharides consist of hundreds to thousands of glucose molecules Starch, glycogen, most fibers © 2017 Pearson Education, Inc © 2017 Pearson Education, Inc â 2017 Pearson Education, Inc Non-nutritive Sweeteners Limited use is not harmful within Acceptible Daily Intake (ADI) • • • • • © 2017 Pearson Education, Inc Saccharin Acesulfame-K Aspartame Sucralose Neotame, Stevia, and Advantame © 2017 Pearson Education, Inc Diabetes • • • • • Impaired blood glucose regulation Type diabetes Type diabetes Gestational diabetes Uncontrolled diabetes can cause nerve damage, kidney damage, blindness, and can be fatal • Hyperglycemia = higher-than-normal blood glucose levels © 2017 Pearson Education, Inc Disorders Related to Carbohydrate Metabolism • Diabetes • • • • Type I Type II Hypoglycemia Lactose Intolerance © 2017 Pearson Education, Inc Diabetes—Type • • • • • • Accounts for 10% of all cases Most cases are diagnosed in adolescence Body does not produce enough insulin Causes hyperglycemia (high blood glucose) Classified as an autoimmune disease Requires insulin injections â 2017 Pearson Education, Inc DiabetesType • • Obesity can trigger cascade of changes resulting in diabetes Insulin insensitivity (insulin resistance): cells become less responsive to insulin Impaired fasting glucose: higher than normal blood glucose, also called prediabetes • Metabolic syndrome: a cluster of risk factors that increase the risk for type diabetes © 2017 Pearson Education, Inc Diabetes—Type • Lifestyle choices can help prevent or control diabetes, healthy diet and exercise lowers risk • Academy of Nutrition and Dietetics strategies: • • • • © 2017 Pearson Education, Inc Eat meals and snacks at regular and planned times Eat about the same amount and types of food Follow Dietary Guidelines for Americans or USDA Food Patterns Seek advice of a registered dietitian/nutritionist © 2017 Pearson Education, Inc © 2017 Pearson Education, Inc â 2017 Pearson Education, Inc Hypoglycemia • Low blood glucose may cause shakiness, sweating, anxiety, weakness Reactive hypoglycemia: pancreas secretes too much insulin after a highcarbohydrate meal • Fasting hypoglycemia: pancreas produces too much insulin, even when someone has not eaten © 2017 Pearson Education, Inc â 2017 Pearson Education, Inc Lactose Intolerance • • • • Insufficient production of lactase to digest lactose-containing foods Not to be confused with milk allergy GI symptoms: gas, cramping, diarrhea Variations in extent of intolerance Need alternate sources of calcium © 2017 Pearson Education, Inc Build A Sandwich PLAY © 2017 Pearson Education, Inc Build A Sandwich ... Secreted by alpha cells of the pancreas Stimulates the liver to convert glycogen to glucose Assists in the breakdown of body proteins for gluconeogenesis, the production of glucose from amino acids... enzymes in the microvilli digest disaccharides to monosaccharides • • • • Maltase Sucrase Lactase Monosaccharides are absorbed into the mucosal cells lining the small intestine and then enter the bloodstream... • Secreted by beta cells of the pancreas Stimulates glucose transporters (carrier proteins) to help move glucose from the blood across the cell membrane • Stimulates the liver and muscle cells