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• Protein-energy malnutrition
(PEM)– Kwashiorkor: severe protein
deficiency– Marasmus: severe calorie
deficiency
Too Much Protein• Heart Disease• Obesity• Osteoporosis• Cancer
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?1. Resting energy expenditure or
(REE)2. Thermic effect of food (TEF)3. 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