W18 Final Exam Study Guide PDF

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Oregon State University

Winter 2017

NUTR 240 Cumulative Final Exam Study Guide

Chapter 7 (this is probably the most complicated section, so spend some time on this chapter…it will also help you understand Chapters 13/14) 1. Understand the difference between catabolic and anabolic reactions and know examples of each related to macronutrients (ex. glucose  glycogen = anabolic, protein  amino acid = catabolic). What are the primary anabolic and catabolic hormones? a. Catabolism is the breakdown, or degradation, of larger molecules to smaller molecules. Catabolism of food begins with digestion, when chemical reactions break down the thousands of proteins, lipids, and carbs into the same small group of end products: amino acids, fatty acids, glycerol, and monosaccharides (glucose). EX: protein to amino acid. Glycogen to glucose. Triglyceride to glycerol and a fatty acid. b. Anabolism is the process of synthesizing larger molecules from smaller ones; it releases chemical energy. EX: glucose to glycogen. Glycerol and fatty acids to triglyceride. Amino acids to proteins. c. a balance between anabolism and catabolism maintains health and function. Anabolism dominates for fetal and childhood growth bc more tissue is being formed than broken down. Catabolism dominates with a disease, bc more tissue is being broken down than repaired. 2. What is the energy currency of cells? ATP How is energy stored in these compounds? The bonds between the phosphate groups store a significant amount of energy called high energy phosphate bonds. When the bonds are broken their energy is released and can be used to do the work of the cell. 3. Name the primary site of cellular energy production. Mitochondria 4. Understand that enzymes are needed to catalyze each step of metabolic pathways (do not need to know specific names). What are coenzymes and cofactors? a. Metabolic pathways are clusters of chemical reactions that occur sequentially to achieve a particular goal: occur in a specific part of a cell or may be limited to specific organ or tissues. b. Coenzymes are non-protein substances that enhance or are necessary for enzyme activity *FAD, FADH and vitamins function as coenzymes. c. Cofactors are typically minerals required for enzyme activity *iron, magnesium, and zinc function as cofactors. 5. What are the three main metabolic pathways involved in cellular energy metabolism? a. Glycolysis-glucose oxidation in order to obtain ATP b. TCA cycle- metabolizes acetyl CoA for the production of carbon dioxide, GTP, and reduced coenyzmes NADH and FADH2 c. Oxidative phosphorylation disposal of the electrons released by glycolysis and citric acid cycle d. Which are aerobic/anaerobic? Glycolysis is anaerobic Where in the cell do they occur? Glycolysis occurs in the cytosol of cells. TCA cycles occurs in the mitochondria. Oxidative phosphorylation occurs in the electron transport chain and in the inner membrane of the mitochondira How much ATP is produced from each pathway? Glycolysis produced a net of 2 ATP to be used as energy for the cell. TCA produces a net of 38. Oxidative phosphorylation produce a net of 30-32 or 36-38 ATP Which pathways are reversible? The Kreb cycle 1|Page

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Oregon State University Winter 2017 6. Understand there are two critical but different processes: production of energy and production of glucose. Why are both needed? 7. Which macronutrient is cellular respiration designed to metabolize? Where do other macronutrients enter these pathways? For protein, know where glucogenic and ketogenic amino acids enter. For lipids, know where glycerol and free fatty acids enter. Know which can be converted to glucose. a. Weather the glycerol and three fatty acids have come from dietary fat or stored body fat, they feed into the same metabolic pathway. Glycerol is converted to pyruvate. Glycerol, the small three carbon backbone of triglycerides does not produce much energy. The liver easily converts glycerol into pyruvate, which is converted into acetyl CoA for entry into the TCA cycle, or it can be used for the regeneration of glucose. For low energy or low carb intake, the body can use the glycerol component of triglycerides as a source of glucose. b. Fatty acids are converted to Acetyl CoA. Fatty acids released from adipose cells are attached to albumin, a blood protein and transported to working cells in need of energy. They are catabolized through fatty acid oxidation. Which takes place in the mitochondria. Process of extracting energy from triglycerides starts with fatty acids and glycerol and ends with the production of carbon dioxide, water, and ATP. c. Fatty acids cannot be converted to glucose. There is no metabolic pathway to convert fatty acid into pyruvate for glucose synthesis. Because cells can’t convert acetyl CoA into glucose. d. Ketones are a by product of fat catabolism. Acetyl CoA enter the TCA cycle can come glucose or fatty acid metabolism. But the TCA cycle functions only when there is adequate oxaloacetate. Someone who has a low carb diets or too little functioning insulin to allow glucose to enter cells, oxaloacetate production falls and TCA cycle decreases. When Acetly CoA builds up, liver cells divert it into ketone bodies. Production increases with low carb intake from fasting, starvation, type 1 diabetes. Someone with Type 1 cant maintain insulin and the body is unable to maintain oxaloacetate, the TCA cycle will shut down, and ketone increases. Ketone bodies are released from liver into blood stream, where they can be taken and used as alternative fuel when glucose isn’t available. 8. What is produced from pyruvate when oxygen is lacking in the cell? When there is no oxygen, pyruvate is converted to lactate. (anaerobic) What happens when oxygen levels are restored? When there is oxygen, pyruvate is converted to Acetyl CoA What is an example of a condition when this might occur? Pyruvate to lactate happens when there is no mitochondria, like red blood cells and the lens and cornea of the eye. Pyruvate to Acetly CoA is when there is mitochondria.. 9. What is the process that metabolizes fatty acids to acetyl CoA? Fatty acid oxidation ***Understand that this process works by cleaving two carbons at a time, so longer fatty acids can produce more energy. Understand why fatty acids cannot be used to make glucose. Because cells cant convery Acetyl CoA into pyruvate for glucose synthesis. 10. Define ketones, ketosis, ketoacidosis. a. Ketones: are by-products if fat catabolism b. Ketosis: occurs when ketones (acidic) inappropriately lower blood pH c. Ketoacidosis: occurs when blood pH falls, further resulting in severe dehydration. 11. Define deamination. Understand the fate of the nitrogen from amino acids during metabolism. a. Deamination: amine group is removed from amino acid; end products are carbon skeleton and ammonia. b. Ammonia is used as nitrogen source for synthesis of nonessential amino acids i. High levels are toxic 2|Page

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Oregon State University Winter 2017 ii. Liver converts ammonia to less toxic area 12. Understand the different sites and relative capacities of energy storage (e.g., glycogen in liver/muscle, triglycerides in adipose). What is the role of stored energy? Stored energy can be used during times of sleep, fasting, or exercise. Extra energy is stored as: carbohydrate in limited amounts as liver and muscle glycogen and fat is unlimited amounts. Why do we consider that there is no storage of protein? The body has no mechanism for storing amino acids or nitrogen. Some free amino acids floating when needed, 13. How can glucose be made when levels are low? Gluconeogenesis: making new glucose from non-carbohydrate precursors a. Primarily from glucogenic amino acids b. Small amount from glycerol (triglyceride) c. Maintains blood glucose during sleep, fasting, trauma, and exercise. d. Protein catabolism for glucose production can draw on vital tissue proteins (skeletal and heart muscles and organ proteins) 14. Understand there are pathways to convert all macronutrients to triglyceride for storage. Lipogenesis: production of fat from nonfat substances such as carbohydrates, ketogenic amino acids, and alcohol. a. When consuming excess calories, acetyl CoA units form fatty acid chains b. Fatty acids combine with glycerol to form triglycerides c. Mostly occurs in liver cells 15. Understand micronutrients do not provide energy but are critical for energy metabolism. i. What are the metabolic responses to feeding? 1. Anabolic state: bloodstream is enriched with glucose, fatty acids, and amino acids. 2. Glucose is stored as glycogen 3. When glycogen stores are saturated, remaining glucose is stored as triglycerides mostly in adipose tissues 4. Amino acids are deaminated and carbon skeletons are converted to fatty acids for storage as triglycerides. ii. Short-term fasting? 1. Liver glycogen is broken down, releasing glucose into the blood. 2. Most cells can switch to using fatty acids as fuel to conserve glucose for brain and other cells that rely on glucose as fuel 3. Ketones form as acetyl CoA units are blocked from entering TCA cycle 4. Glucose synthesis from glycogenic amino acids and glycerol iii. Long term-fasting? 1. The body shifts to survival mode 2. Blood glucose is maintained to support brain and red blood cells 3. Decline in activity, body temperature, and resting metabolic rate 4. Fatty acids become the primary fuel 5. Brain cells start to use ketone bodies 6. Muscle (skeletal, cardiac) and organ proteins supplies glucose

Chapter 14 1. Be able to list the benefits of physical activity. a. Reduced risk of heart disease, strengthens heart, reduces risk of high blood pressure. b. Increases lung efficiency and capacity c. Reduces risk of type 2 diabetes d. Reduces risk of colon cancer 3|Page

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Oregon State University Winter 2017 e. Strengthens immune system f. Strengthens bones g. Reduces risk of bone, muscle, and joint injuries h. Promotes healthful body composition and weight management i. Benefits psychological health and stress management Understand the four components of the FITT principle. a. Frequency b. Intensity c. Time d. type Know that energy metabolism is impacted by the factors described by the FITT component and the fuel state of the body (fed/fasted). Understand how long ATP and CP can fuel physical activity. a. All are working all the time i. ATP-CP ii. ATP- 1-3 seconds iii. CP- 3-15 seconds iv. Anaerobic Glycolysis v. Oxidative phosphorylation (Aerobic Metabolism) b. The proportion of each system used is determined by i. Intensity of activity ii. Duration of activity iii. Training level of individual iv. Amount an type of muscle being used v. Fueling state of the body 1. Fed, fasting, starvation c. ATP must be generated continuously since muscles store only enough ATP for 1-3 seconds of activity d. ATP is generated from the breakdown of carb, fat, and protein e. After depleting ATP stores, muscles turn to other sources: i. Creatine phosphate (CP) stores some energy that can be used to make ATP ii. CP stores enough energy for 3-15 seconds of maximal physical effort; hence, CP is used for very intense brief activity bursts iii. Breakdown of carbohydrates fuels both brief and long-term exercise. Understand what metabolic pathways are occurring when oxygen is limited. a. With limited oxygen, pyruvate is converted to lactic acid: a fuel source for working muscles, heart, and resting tissues. b. Excess lactic acid goes back to the liver to be converted back into glucose via the Cori cycle. c. Glucose metabolism i. Anaerobic breakdown of glucose yields 2 ATP molecules ii. Aerobic breakdown of glucose yields 36-38 Describe how carbohydrates and fats are used during different intensity of physical activity. a. (fat triglycerides) can be metabolized to generate ATP i. For low-intesity exercise ii. For excerise of long duration (marathons) iii. Abundant energy source, even in lean people iv. 2X more energy per gram than carbohydrates v. Slow in breaking down 4|Page

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Oregon State University Winter 2017 vi. Primary energy source during rest, sitting, and standing in place; also endurance events b. Carbohydrates and fats can both be used as energy sources for ATP production i. Carbohydrates are mostly used for high intensity activity ii. Fats are used for low-intensity exercise iii. ** proteins (amino acids) are not a major fuel sources for exercise. 7. Understand that protein is not a major fuel source during physical activity and that most people obtain adequate protein in their diets in the US. 8. Be able to list the top three nutrition issues for athletes. 1. Under fueling 2. Inadequate or excessive recovery nutrition 3. Under and De-hydration 9. Define carbohydrate loading and understand when it may be appropriate. a. Also called glycogen loading b. Alter exercise duration and carbohydrate intake to maximize muscle glycogen c. Does not always improve performance d. Side effects: gastrointestinal distress; feeling heavy, bloated and sluggish 10. Understand the role of hydration for physical activity. a. Lubricant that bathes tissues and cells b. Transportation of nutrients, hormoens, waste products c. Component of chemical reactions d. Part of body tissues (proteins and glycogen) e. Temperature regulation: evaporative cooling f. Drink water for activites lasting under 1 hour g. For activites long than 1 hour, consume sports drinks with carbohydrates and electrolytes h. Drink fluids before, during and after exercise i. Thirst mechanism is not reliable j. Limit drinks containing fructose k. Generally, avoid caffeine, alcohol and carbonated beverages.

Chapter 13  Define energy balance. a. Fluctuations in weight depend on: Energy intake and energy expenditure. b. Energy balance equation: i. Energy intake=energy expenditure ii. Energy intake is kacal from food, beverages iii. Energy expenditure is energy expended at rest and during physical activity.  What is BMI? Body mass index is a ratio of a person body weight to the square of their height. How is it measured? BMI=weight(lb.)/height (in)^2 What are the benefits/drawbacks of this measurement method? a. It is not an indication of body composition b. Not appropriate for use in older adults (bone and muscle loss) and children (bone and muscle growth), athletes, pregnant, and lactating women. c. Doesn’t account for physical and metabolic differences in ethnic backgrounds How is BMI used to classify weight status? a. Underweight: BMI less than 18.5 kg/m and having too little body fat to maintain health b. Normal weight: BMI between 18.5 and 24.9 c. Overweight: BMI between 25 and 29.9 and having a moderate amount of excess body fat 5|Page

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Oregon State University Winter 2017 d. Obese: BMI between 30 and 39.9 and having an excess of body fat that adversely affects health, increasing disease risk significantly e. Morbid obesity: BMI greater or equal to 40 and body weight exceeding 100% of normal, a very high risk for serious health consequences.  Be able to calculate BMI and classify as underwt, healthy wt, overwt or obese.  Understand the concept of body composition and examples of how it can be measured (DXA, bioelectrical impedance, etc.) Body composition is the ratio of a persons body fat to lean body mass. Types of measurement: a. Underwater weighing b. Skinfolds c. Bioelectrical impedance analysis (BIA) d. Dual energy x-ray absorptiometry (DXA) e. Bod Pod 1. Know the patterns of body weight distribution (apple/android and pear/gynoid) and which is associated with health risk. a. Apple-shaped fat patterning: upper body i. Increased risk for chronic diseases ii. Men tend to store fat in the abdominal region b. Pear-shaped fat patterning: lower body i. No significant increased chronic disease risk ii. Women tend to store fat in the lower body. c. Are there sex differences? Yes How can we measure body fat distribution? i. waist-to-hip ratio:  Men: higher than 0.90  Women: higher than 0.80 ii. Waist circumference  Men: above 40 in  Women: above 35 in 2. What are the three components of daily energy expenditure and how do they differ?  Basal metabolic rate (BMR) 60-75% a. The energy the body expends to maintain its fundamental physiologic functions. Higher lean body mass=higher BMR  Thermic effect of food (TEF) 5-10% a. The energy we expend to digest, absorb, transport, metabolize, and store the nutrients we need.  Energy cost of physical activity 15-35% a. The energy that is expended on body movement and muscular work above basal levels. b. Which one is the most variable among people? BMR c. Which one is the least variable? TEF d. Which one can be the most variable within an individual (in other words, where do we have the most control?) energy cost of physical activity 3. What factors affect BMR (basal metabolic rate), and do these factors increase or decrease BMR? a. Factors that increase: i. Higher lean body mass ii. Greater height iii. Younger age iv. Elevated levels of thyroid hormone 6|Page

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Oregon State University Winter 2017 v. Stress, fever, illness vi. Male gender vii. Pregnancy and lactation viii. Certain drugs, stimulants, caffeine, and tobacco b. Factors that decrease: i. Lower lean body mass ii. Lower height iii. Older age iv. Depressed levels of thyroid hormone v. Starvation, fasting or very low-calorie diets vi. Female gender due to decreased lean tissue 4. What are the three energy related hormones mentioned in the textbook (pages 514-515)? a. Leptin- is a protein produced by adipose cells. It acts to reduce food intake and to cause a decrease in body weight and body fat. Obese people tend to have very high amounts of leptin in their body but are insensitive to its effects. b. Ghrelin- a protein synthesized in stomach. Role is in appetite regulation through its actions in the hypothalamus. Stimulates appetite and increases the amount of food one eats. Levels increase before a meal and fall within 1 hour after a meal. c. Peptide YY or PYY- protein produced in the gastrointestinal tract. It is released after a meal, in amounts proportional to the energy content of the meal. Decreases appetite and inhibits food intake. Obese induvial have lower levels of PYY when they are fasting and show less of an increase in PYY after a meal. 5. What are other factors associated with weight health? a. Genetic factors i. FTO gene ii. Thrifty gene theory iii. Set point theory b. Metabolic factors i. Low metabolic rate ii. Low level of spontaneous physical activity iii. Low sympathetic NS activity iv. Abnormally low level thyroid hormone v. Certain prescription medications c. Physiologic factors i. Hunger and satiety ii. Proteins affect the regulation of appetite and storage of body fat.  Leptin  Ghrelin  Peptide YY  Uncoupling proteins in brow adipose tissue increase energy expenditure iii. Increase satiety  Hormones: serotonin, CCK  Increase in blood glucose levels after meal  Stomach expansion  Nutrient absorption from the small intestine iv. Decrease satiety  Hormones: beta-endorphins  Neuropeptide Y  Decreased blood glucose levels 7|Page

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Oregon State University d. Cultural and economic factors i. Religious beliefs ii. Learned food preferences iii. Fast food culture iv. Sedentary lifestyle v. Economic status vi. Educational attainment vii. Access to healthcare e. Social factors i. Appetite: psychological drive to eat ii. Meal timing and size: portion distortion iii. Sight and fragrance of foods iv. Mood, depression v. Barriers to physical activity vi. Technological lifestyle vii. Social pressures and underweight

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InDepth 13.5: Eating Disorders –  Anorexia Nervosa- Self starvation leading to a severe nutrient deficiency DSM definition? Restriction of energy intake relative to requirements leading to a significantly low i. body weight in the context of age, sex, developmental trajectory, and physical health. ii. Intense fear of gaining weight or becoming fat, even though underweight iii. Disturbance in the way in which ones body weight or shape is experienced, undue influence of body ...