Midterm 2 Review Chapters 5-8
Midterm #2 • Chapters 5-8 • Multiple Choice and True/False (50) • Multi-part Short Answers (4) • Bring: Scantron, Non-graphing calculator, pencil, eraser
Chapter 5: Carbohydrates • Carbohydrates include sugars, starches, and fibers • Major food sources: plants • Two main carbohydrate types: • Simple (sugars): mono + disaccharides • Complex (starches and fiber) • Bond: alpha or beta glycosidic bonds
Carbohydrates • High Fructose Corn Syrup • Complex Carbohydrates • Starch vs. Glycogen • Amylose (straight) vs. Amylopectin (branched) • Fiber: non-digestible before entering large intestine • Soluble: dissolves in water gel-like slows digestion • Fermentable • Insoluble: does not dissolve in water creates a bulk larger, softer stool • Fermentable (Resistant Starch) vs. Non-Fermentable
Fiber Diagram
Carbohydrates Digestion & Absorption • Mouth: Salivary amylase • Small intestine: • Enzymes: pancreatic amylase, brush border enzymes • End product: Glucose • Liver stores and releases glucose to maintain blood glucose • Large intestine: • Bacteria in colon digests rest of carbohydrates, soluble fiber, and resistant starch (a type of insoluble fiber) to gas + short chain fatty acids energy supply for colon cells
Regulating Blood Glucose Levels
Carbohydrates and Health • Glycemic Index • Hyperglycemia vs. Hypoglycemia • Hyperglycemia consequences: sweet urine, ketosis/acidosis (if you are also diabetic) • Hypoglycemia: • Reactive Hypoglycemia • Fasting Hypoglycemia • Consequences: ketosis/acidosis, coma death • Diabetes I, II, Gestational Diabetes
Carbohydrates in your diet • Nutritive vs. Non-nutritive sweeteners • Nutritive: • Natural, Refined, Sugar Alcohol • Can be “sugar free,” but not always calorie free • Non-Nutritive: “Artificial sugar” • Saccharin (bladder cancer), Aspartame (PKU), Acesulfame K (Stable under heat), Sucralose
Chapter 6: Lipids • Types: Triglycerides, Phospholipids, Sterols • Made of: Glycerol + Fatty Acids • Bonds and Saturation: • Saturated fatty acids vs. Unsaturated fatty acids (MUFA, PUFA) • Saturated fatty acids: all single bonds • Unsaturated fatty acids: Cis (natural) vs. Trans fatty acids (partial hydrogenation) • Essential vs. Non-essential fatty acids
Lipids • Triglycerides • Functions: energy storage, insulation/protection, etc. • Visceral vs. Subcutaneous fat • Food sources by most prevalent type: Saturated (animal) vs. Polyunsaturated (plants) • Phospholipids: • Functions: Emulsifier (bile, lingual lipase), Structural element for cell membrane (lipoprotein carrier) • Sterols • Functions: structural component, precursors to other substances
Lipid Absorption
Lipoprotein Pathway Summary
Lipid Digestion • Fat hydrogenation Pros/Cons • Lipids and Health • AHA diet and lifestyle recommendations • Metabolic Syndrome • Cancer
Proteins • Made up of: Amino acids • Essential, Non-Essential, Conditionally essential • Bond: Peptide bond • Denaturalization of Protein (factors and consequence) • Functions of Body Proteins
Summary of Protein Digestion and Absorption
Function of Blood Amino Acid Pool
Protein in the Diet • Nitrogen balance • Recommended protein intake • Adult RDA = 0.8g/kg of body weight • Infants have highest needs relative to body weight • Physical stress increase your body’s needs for proteins • Protein Quality: Complete vs. Incomplete • Vegan vs. Vegetarian, Pros/Cons
Health Effects of Protein Too Little Protein Too Much Protein Heart Disease Obesity Osteoporosis Cancer • Protein-energy malnutrition (PEM) • Kwashiorkor: severe protein deficiency • Marasmus: severe calorie deficiency
Energy Balance and Weight Management • Energy input vs. output • Food intake is regulated by sensations of hunger, satiation, satiety, appetite • Physiological vs. psychological • Internal (physiological response) vs. External cues (environment) • Internal: sense of fullness, NPY, Ghrelin, Leptin • External: diet composition, sensory properties, portion size, environment/social, emotion
How does our bodies use energy? Resting energy expenditure or (REE) Thermic effect of food (TEF) Physical activity (PA) REE + TEF + PA = Total Energy Expenditure
Measuring Body Weight and Fat • Body composition • Is the relative amount of fat and lean muscle mass • Assess body weight via BMI • Assess body fat via DEXA/DXA, Underwater weighing, BodPod, Skinfold measurements, Bioelectrical impedance
Overweight and Obesity • US: 2/3 or 66% of American adults are overweight/obese • Factors in development of obesity • Biology: genetics, race, fat cell development, sex/age • Social environmental factors: socioeconomic status, built environment, social factors • Lifestyle and behavior: psychological, physical activity • Weight cycling or “yo-yo dieting”
Diet and Eating Habits • Adopting a healthy behaviors • Crash diets don’t work • Balancing energy sources: Carbs (45-65%), Fats (20-25%), Proteins (10-35% of total calories) • Weight management approaches • Underweight
Resources • Your required textbook • Lecture Notes • Practice Quiz (online) • Classmates • Professor
