Chapter 4 Metabolism, Energy, and the Basic Energy Systems 1. The food sources from which we derive energy are composed mainly of a. carbon, calcium, nitrogen, and sodium b.
carbon, hydrogen, oxygen, and phosphorus c. calcium, hydrogen, nitrogen, and sodium d. carbon, hydrogen, nitrogen, and oxygen Answer: _____ 2.
Carbohydrates are stored in the body as a. glycogen b. adenosine triphosphate c.
glucose d. triglycerides Answer: _____ 3. Which of the following statements is true regarding the relative roles of fat, carbohydrate, and protein as energy sources for cellular metabolism?
a. Much more energy is stored in the body in the form of carbohydrate than in the form of fat. b.
Protein is the predominant fuel source during exercise. c. Fat cannot provide all of the energy required for high-intensity muscular activity because the rate of energy release from fat is too slow.
d. Since glycogen reserves in the body are so large, only limited amounts of carbohydrate are needed in the daily diet. Answer: _____ 4.
During maximal, short-duration exercise, ATP is generated almost exclusively from a. fat b. carbohydrate c.
protein d. vitamins and minerals Answer: _____ 5. List and briefly describe the three basic energy systems that provide energy for cellular activity.
Answer: 6. The body ... more. less.
stores much more energy in the form of fat than in the form of glycogen. a.<br><br> True b. False Answer: _____ 7. Fat provides more kilocalories per gram than carbohydrate, but oxidation requirements for fat are greater than oxidation requirements for carbohydrate.<br><br> a. True b. False Answer: _____ 8.<br><br> The fuel source most likely to limit endurance is _______________. Answer: 9. The process of converting ADP to ATP by the addition of a phosphate group is called a.<br><br> hydrolysis b. aerobic metabolism c. phosphorylation d.<br><br> anaerobic metabolism Answer: _____ 10. Intracellular stores of ATP and PCr are sufficient to support maximum muscular effort for approximately a. 1 to 4 seconds b.<br><br> 3 to 15 seconds c. 30 seconds to 2 minutes d. 1 to 2 hours Answer: _____ 11.<br><br> Phosphocreatine is a high-energy phosphate compound that is used in the cell a. to resynthesize ATP b. to transport ATP to the mitochondria c.<br><br> as a direct source of energy for the cell d. as a rate-limiting enzyme in the metabolism of fat and carbohydrate Answer: _____ 12. Before fat can be metabolized by the muscle cells, it must first be broken down into a.<br><br> free fatty acids and glycogen b. free fatty acids and glycerol c. triglycerides and glucose d.<br><br> amino acids and glycerol Answer: _____ 13. The process by which glycogen is synthesized from glucose is called a. gluconeogenesis b.<br><br> glycogenolysis c. glycolysis d. glycogenesis Answer: _____ 14.<br><br> Most of the energy for a 2-hour bout of exercise is provided by a. the glycolytic system b. the ATP-PCr system c.<br><br> the oxidative system d. glycogenesis Answer: _____ 15. Which of the following statements is not an accurate description of anaerobic glycolysis?<br><br> a. It takes place in the cytoplasm of the cell. b.<br><br> It generates large amounts of ATP. c. It produces lactic acid.<br><br> d. It is an important source of energy during high-intensity exercise that is sustained for 1 to 2 minutes. Answer: _____ 16.<br><br> Which of the following measurements is necessary when assessing the rate of protein metabolism by the body? a. fecal protein content b.<br><br> urine nitrogen excretion c. volume of expired carbon dioxide d. respiratory exchange ratio Answer: _____ 17.<br><br> The synthesis of glycogen from glucose is called a. glycolysis b. gluconeogenesis c.<br><br> glycogenolysis d. glycogenesis Answer: _____ 18. For each liter of oxygen consumed by the body, which substrate provides the greatest number of kcal of energy?<br><br> a. protein b. fat c.<br><br> carbohydrate d. All three provide the same number of kcal Answer: _____ 19. Which of the following factors influences your basal metabolic rate?<br><br> a. heat stress b. emotional stress c.<br><br> body size d. all of the above Answer: _____ 20. The major metabolic waste product that causes the muscles and blood to have a lower pH during exercise of increasing intensity is a.<br><br> bicarbonate b. nitrogen c. carbon dioxide d.<br><br> lactate Answer: _____ 21. The two high-energy compounds critical for all physical activity are a. ATP and PCr b.<br><br> AMP and PCr c. AMP and ADP d. ATP and ADP Answer: _____ 22.<br><br> ________________ can be metabolized either aerobically or anaerobically. a. Fat b.<br><br> Protein c. Carbohydrate d. PCr Answer: _____ 23.<br><br> All-out maximal exercise of 6-s duration would stress a. the ATP-PCr system b. the glycolytic system c.<br><br> the oxidative system d. all three systems equally Answer: _____ 24. NAD and FAD are a.<br><br> enzymes that catalyze chemical reactions in glycolysis b. enzymes that catalyze chemical reactions of the Krebs cycle c. coenzymes that transfer hydrogens to the electron transport chain d.<br><br> two important end products of oxidative phosphorylation Answer: _____ 25. Which of the following fuels is least preferred by the cells for energy production during highly anaerobic exercise? a.<br><br> protein b. carbohydrate c. fatty acids d.<br><br> All three fuels are equally preferred. Answer: _____ 26. The process by which triglycerides are broken down into glycerol and free fatty acids is called a.<br><br> lipogenesis b. lipolysis c. hydrolysis d.<br><br> beta oxidation Answer: _____ 27. During cellular metabolism, the rate of energy release from chemical compounds is regulated by special proteins called enzymes. a.<br><br> True b. False Answer: _____ 28. Amino acids are the primary source of energy during sprint exercise.<br><br> a. True b. False Answer: _____ 29.<br><br> The process of breaking down liver or muscle glycogen into glucose-1-phosphate is referred to as glycogenesis. a. True b.<br><br> False Answer: _____ 30. Beta oxidation is the name for a. the series of reactions by which glucose is converted to pyruvic acid in cell cytoplasm b.<br><br> the series of reactions making up the electron transport chain c. the process by which free fatty acids are broken down to yield multiple molecules of acetyl CoA d. the process by which proteins are metabolized aerobically in the mitochondria Answer: _____ 31.<br><br> The two enzymes most commonly measured in order to assess the oxidative capacity of muscle tissue are a. succinate dehydrogenase and citrate synthase b. phosphofructokinase and lactate dehydrogenase c.<br><br> nicotinamide adenine dinucleotide and flavin adenine dinucleotide d. ATPase and creatine kinase Answer: _____ 32. Endurance-trained muscles have oxidative enzyme activities that are somewhat less than those seen in untrained subjects.<br><br> a. True b. False Answer: _____ 33.<br><br> Fast-twitch muscle fibers are best suited for glycolytic energy production. a. True b.<br><br> False Answer: _____ 34. During near-maximal exercise, significant amounts of lactic acid are generated by the ATP-PCr energy system. a.<br><br> True b. False Answer: _____ 35. Describe the relative contributions of each of the three basic energy systems to meeting the energy demands during (a) very brief (5 to 10 seconds) maximal muscular activity, (b) high-intensity muscular activity lasting 1 to 2 minutes,; (c) moderate-intensity muscular activity lasting for 30 minutes or more.<br><br> Answer: 36. Describe the roles of NAD and FAD in oxidative phosphorylation. Answer: 37.<br><br> Describe the relative contributions of fat, carbohydrate, and protein to meeting energy demands during exercise. Answer: 38. Indirect calorimetry a.<br><br> assesses the body's energy expenditure by measuring heat production b. can track rapid changes in energy expenditure, whereas direct calorimetry cannot c. uses measurements of respiratory gases in estimating energy expenditure d.<br><br> a and b are correct e. b and c are correct Answer: _____ 39. The respiratory exchange ratio (RER) is defined as the ratio between the a.<br><br> amount of CO 2 produced and the amount of CO 2 consumed during metabolism b. amount of O 2 produced and the amount of O 2 expired during metabolism c. amount of CO 2 released and the amount of O 2 consumed during metabolism d.<br><br> amount of O 2 released and the amount of CO 2 consumed during metabolism Answer: _____ 40. Which of the following is not a potential limitation of the RER as an indicator of the relative contributions of carbohydrate, fat, and protein to meeting the energy requirements of exercise? a.<br><br> The RER does not account for protein, which may contribute up to 5% of the total energy during prolonged exercise. b. Oxidation of fat requires more oxygen than oxidation of carbohydrate.<br><br> c. Energy derived from catabolism of fat and amino acids in the liver to produce glucose may cause an underestimation of the carbohydrate contribution to exercise energy demands. d.<br><br> During high-intensity exercise, exhaled CO 2 may reflect lactate accumulation in the blood as well as metabolic production of CO 2 . Answer: _____ 41. Carbon-13 is not used to measure energy metabolism in humans because it is a dangerous radioisotope.<br><br> a. True b. False Answer: _____ 42.<br><br> Direct calorimetry is the most commonly used method for assessing energy expenditure during exercise. a. True b.<br><br> False Answer: _____ 43. Tracer techniques utilizing isotopes such as deuterium or carbon-13 are well suited for measurements of acute exercise metabolism. a.<br><br> True b. False Answer: _____ 44. Explain the advantages and disadvantages of using isotopes for the measurement of whole-body energy metabolism.<br><br> Answer: 45. If a runner's RER averaged 0.95 (caloric equivalence of 4.99 kcal/L of oxygen) during a 60-min run, how many calories would he or she use if average oxygen uptake was 3 L/min? Show your calculations.<br><br> Answer: 46. The so-called slow component of oxygen-uptake kinetics observed during exercise at power outputs above the lactate threshold is probably most closely related to a. recruitment of a higher percentage of fast-twitch muscle fibers b.<br><br> increased oxygen cost associated with ventilation c. increased body temperature d. a shift from fat metabolism to carbohydrate metabolism Answer: _____ 47.<br><br> Normally active 20-year-old females, on average, have a maximal oxygen uptake of about a. 70 ml/kg/min b. 40 ml/kg / min c.<br><br> 4 ml/kg / min d. 5 ml/kg / min Answer: _____ 48. In sedentary individuals, decreases by about _____________ after the age of 25.<br><br> 2 VO max & a. 1% per year b. 3% per year c.<br><br> 5% per year d. 5% per decade Answer: _____ 49. The difference between the oxygen required for a given rate of steady-state work and the oxygen actually consumed is referred to as the a.<br><br> maximal oxygen uptake b. excess postexercise oxygen consumption c. oxygen deficit d.<br><br> oxygen surplus Answer: _____ 50. The lactate threshold is best defined as the point during exercise of increasing intensity a. when the body shifts from aerobic to anaerobic metabolism b.<br><br> when lactic acid begins to be produced by the muscles c. when one begins to feel out of breath d. when the rate of lactate production begins to exceed the rate of lactate clearance Answer: _____ 51.<br><br> Lactate threshold is a good predictor of a. muscular strength b. muscular endurance c.<br><br> distance running performance d. sprint performance Answer: _____ 52. Individuals who are efficient runners tend to use __________ oxygen when running at a given speed, compared to individuals who are inefficient runners.<br><br> a. more b. far more c.<br><br> less d. about the same amount of Answer: _____ 53. Which of the following activities requires the greatest rate of energy expenditure (kcal/min)?<br><br> a. cycling at 7.0 mph b. female swimming (crawl stroke) at 3.0 mph c.<br><br> male swimming (crawl stroke) at 3.0 mph d. running at 10 min per mile (6.0 mph) Answer: _____ 54. Maximal oxygen uptake is regarded as one of the best single indicators of one's capacity for endurance exercise.<br><br> a. True b. False Answer: _____ 55.<br><br> Under resting conditions, nearly all of the body's energy requirements are supplied via oxidation of fat. a. True b.<br><br> False Answer: _____ 56. The slow component of oxygen-uptake kinetics is also referred to as drift. 2 VO & a.<br><br> True b. False Answer: _____ 57. Accumulation of lactate in the blood is determined by the balance between lactate production and lactate clearance.<br><br> a. True b. False Answer: _____ 58.<br><br> Lactate threshold generally occurs at a higher percentage of in endurance-trained individuals than in untrained individuals. 2 VO max & a. True b.<br><br> False Answer: _____ 59. During exercise of increasing intensity, the point at which blood lactate begins to accumulate above resting levels is called the __________________. Answer: 60.<br><br> List the factors that affect basal metabolic rate (BMR) and explain how they might alter one's BMR. Answer: 61. Discuss the relationship between fat-free mass and basal metabolic rate (BMR).<br><br> Answer: 62. What factors might explain why trained competitive female swimmers are more efficient in swimming than trained competitive male triathletes who have no competitive swimming background? Answer: 63.<br><br> Discuss the influence of body mass (weight) on energy expenditure during running. Answer: 64. Outline the factors that are responsible for the improved capacity of muscles to generate energy during endurance exercise.<br><br> Answer: 65. Discuss the relationship between a muscle's fiber-type composition and its oxidative capacity. Answer: 66.<br><br> List four factors that appear to determine one's success in endurance activities. Answer: 67. Which of the following would likely account for the fatigue experienced by a marathon runner?<br><br> a. glycogen depletion and hypoglycemia b. low muscle pH c.<br><br> high levels of blood lactate d. depletion of intracellular PCr Answer: _____ 68. A failure of neural impulse transmission across the neuromuscular junction may be one cause of _________________ during exercise.<br><br> Answer: