metabolism & energetics
Which of the following statements concerning free fatty acids is FALSE? a. Free fatty acids cannot diffuse easily across cell membranes. b. Free fatty acids can be metabolized by many body cells. c. Free fatty acids can diffuse out of lipid stores when triglycerides are broken down. d. Free fatty acids in the blood are usually bound to albumin.
a
Excess cholesterol leaves somatic cells and is absorbed by __________, which then transport the cholesterol back to the liver. a. HDLs b. LDLs c. chylomicrons d. VLDLs
a
Glycolysis occurs in the __________. a. cytoplasm b. mitochondria c. nucleus d. cell membrane
a
The process that breaks down organic substrates, releasing energy that can be used to synthesize ATP or other high-energy compounds, is __________. a. catabolism b. anabolism c. oxidation d. metabolism
a
What is the primary function of very low-density lipoproteins (VLDLs)? a. transporting the triglycerides to peripheral tissues b. transporting cholesterol from peripheral tissues back to the liver c. transporting cholesterol to peripheral tissues d. carrying absorbed lipids from the intestinal tract to circulation
a
Which of the following hormones does NOT have important functions during the postabsorptive state? a. insulin b. cortisol c. epinephrine d. glucagon
a
The TCA, or Krebs, cycle takes place in the __________. a. cell membrane b. mitochondria c. cytoplasm d. nucleus
b
A diet deficient in essential fatty acids would __________. a. alter the appearance of the skin b. cause a decrease in the production of prostaglandins c. slow growth d. slow growth, alter the appearance of the skin, and cause a decrease in the production of prostaglandins
d
Although small quantities of lipids are normally stored in the liver, most of the synthesized triglycerides are bound to __________. a. hepatocytes in the liver b. adipocytes c. glucose molecules d. transport proteins
d
Amino groups can be removed from amino acids by __________. a. transamination b. amination c. deamination d. both deamination and transamination
d
Because infants cannot control their thermoregulatory rates, they __________. a. possess a specialized type of adipose called brown fat b. also cannot shiver c. must be dried and promptly bundled to keep them warm d. All of the listed responses are correct.
d
Nicotinamide adenine dinucleotide (NAD) and flavin adenine dinucleotide (FAD) pick up the majority of hydrogen ions and electrons from which step in the aerobic cellular respiration? a. glycolysis b. electron transport phosphorylation c. tricarboxylic acid (TCA) cycle d. conversion of pyruvic acid to lactic acid
c
The actual process of ATP formation associated with the electron transport system is called __________. a. substrate-level phosphorylation b. photophosphorylation c. chemiosmosis d. active transport
c
The efficiency rate for the complete catabolism of glucose is about __________. a. 12 percent b. 32 percent c. 42 percent d. 90 percent
c
The first step in a sequence of enzymatic reactions in the tricarboxylic acid cycle is the formation of __________. a. pyruvic acid b. acetyl-CoA c. citric acid d. oxaloacetic acid
c
The synthesis of glucose from nonglucose precursors is known as __________. a. glycogenesis b. lipolysis c. gluconeogenesis d. beta-oxidation
c
The transition between glycolysis and the TCA cycle involves a molecule called __________. a. carboxylase b. glucose-6-phosphate c. acetyl coenzyme A d. dihydroxyacetone phosphate
c
When blood glucose concentrations are elevated, the glucose molecules are __________. a. used for tissue repair b. used to build proteins c. catabolized for energy d. catabolized for energy, used to build proteins, and used for tissue repair
c
Which of the following foods are DEFICIENT in dietary fiber? a. rice and pastas b. breads and cereals c. milk and meat d. vegetables and fruits
c
Which of the following is NOT an essential fatty acid? a. linolenic acid b. linoleic acid c. glutamic acid d. None of the listed responses is correct.
c
Which of the following is a nitrogen compound important in energy storage in muscle tissue? a. porphyrin b. glycoprotein c. creatine d. pyrimidine
c
Why are minerals, vitamins, and water classified as essential nutrients? a. They are used by the body in large quantities. b. They are the major providers of calories for the body. c. The body cannot synthesize the nutrients in sufficient quantities. d. All of the listed responses are correct.
c
Oxidative phosphorylation produces __________ percent of the ATP in our cells. a. 9 b. 36 c. 40 d. 90
d
Some amino acids can be used to make ATP because they can be converted to __________. a. lactic acid b. pyruvic acid c. acetyl CoA d. both pyruvic acid and acetyl CoA
d
The basal metabolic rate (BMR) is __________. a. the minimum resting energy of an awake, alert person b. 70 cal/hr or 1680 cal/day in the average individual c. measured by monitoring respiratory activity d. all of the listed responses
d
The direct transfer of energy through physical contact is called __________. a. evaporation b. convection c. radiation d. conduction
d
The factors that make protein catabolism an IMPRACTICAL source of quick energy include which of the following? a. Proteins are more difficult to break apart. b. Proteins are important structural and functional cellular components. c. One of the by-products, ammonia, is a toxin that can damage cells. d. All of the listed responses are correct.
d
The four processes involved in heat exchange with the environment are __________. a. sensible, insensible, heat loss, and heat gain b. thermogenesis, dynamic action, pyrexia, and thermolysis c. physiological, behavioral, generational, and acclimatization d. radiation, conduction, convection, and evaporation
d
The most important factors in good nutrition are to obtain nutrients __________. a. that meet the recommended daily intakes b. that are low in fats and high in dietary fiber c. from the food pyramid d. in sufficient quantity and quality
d
The products of glycolysis include which of the following? a. pyruvic acid b. ATP c. NADH d. All of the listed responses are correct.
d
To examine the metabolic state of an individual, results may be expressed as __________. a. calories per unit of body weight per day b. calories per hour c. calories per day d. calories per hour, calories per day, and calories per unit of body weight per day
d
Under normal circumstances, if you eat three meals a day, the body will spend approximately 12 hours in the __________. a. digestion of food b. excretion of waste c. postabsorptive state d. absorptive state
d
What is the effect of androgens and estrogens on general peripheral tissues? a. increased glycogenolysis b. increased reliance on ketone bodies and fatty acids c. increased glucose uptake and utilization d. increased amino acid use in protein synthesis
d
Which of the following carries lipids from the digestive tract to the circulatory system? a. IDL b. VLDL c. HDL d. chylomicrons
d
Which of the following has been implicated in plaque buildup and cardiovascular disease? a. VLDL b. HDL c. chylomicrons d. LDL
d
Which of the following hormones exhibits its influence most during the postabsorptive state? a. estrogen b. growth hormone c. insulin d. glucagon
d
In resting skeletal muscles, a significant portion of the metabolic demand is met through the __________. a. anabolism of ADP to ATP b. catabolism of fatty acids c. catabolism of glycogen d. catabolism of glucose
b
In terms of the movement of electrons, the gain of electrons is called reduction, whereas the loss is called __________. a. metabolism b. oxidation c. catabolism d. anabolism
b
Lucy, a 35-year-old woman, says she CANNOT lose the fat around her abdomen because it is brown fat. You correct her by saying that the only people with brown fat are __________. a. teenagers b. infants c. anorexic women d. elderly men
b
Neurons must be provided with a reliable supply of glucose because they are __________. a. involved primarily with transmitting nerve impulses b. usually unable to metabolize other molecules c. primarily located in the brain d. covered with myelinated fibrous sheaths
b
The breakdown of fatty acid molecules results in the production of __________. a. glycogen b. acetyl coenzyme A c. coenzyme Q d. coenzyme A
b
The breakdown of fatty acid molecules yields __________ the breakdown of similar carbohydrates. a. the same amount of ATP as b. more ATP than c. various amounts of ATP compared with d. less ATP than
b
The final acceptor of electrons passing through the electron transport chain is __________, which in turn binds with hydrogen ions to produce __________. a. oxygen, ozone b. oxygen, water c. carbon, carbon dioxide d. carbon dioxide, methane
b
The synthesis of glucose from noncarbohydrates is called __________. a. glycogenolysis b. gluconeogenesis c. glycolysis d. glycogenesis
b
The synthesis of glucose from nonglucose precursors is known as __________. a. beta-oxidation b. gluconeogenesis c. lipolysis d. glycogenesis
b
The trace minerals found in extremely small quantities in the body include __________. a. phosphorus, zinc, copper, and potassium b. iron, zinc, copper, and manganese c. sodium, potassium, chloride, and calcium d. phosphorus, magnesium, calcium, and iron
b
A person who consumes very low amounts of vitamin C over a long period of time is at risk for developing __________. a. itching and tingling b. hypotension c. scurvy d. polycythemia
c
During open-heart surgery, which of the following thermoregulatory changes will be induced on the patient's body? a. nonshivering thermogenesis b. sweating c. hypothermia d. heat exhaustion
c
Most pathways of lipogenesis begin with __________. a. coenzyme A b. dihydroxyacetone phosphate c. acetyl coenzyme A d. amino acids
c
NAD, a key coenzyme used in the process of producing ATP, is produced from which water-soluble vitamin? a. vitamin B2 b. riboflavin c. niacin d. vitamin B12
c
In the beta-oxidation of an 18-carbon fatty acid molecule, the cell gains __________. a. 36 ATP b. 38 ATP c. 78 ATP d. 144 ATP
d
A cell with excess carbohydrates, lipids, and amino acids will break down carbohydrates to __________. a. obtain energy b. provide metabolic regulation c. provide tissue growth and repair d. obtain energy, provide tissue growth and repair, and provide metabolic regulation
a
An individual's basal metabolic rate ideally represents __________. a. the minimum resting energy expenditure of an awake, alert person b. the amounts of circulating hormone levels in the body c. the daily energy expenditures for a given individual d. genetic differences among ethnic groups
a
For each glucose molecule converted to two pyruvates, the anaerobic reaction sequence in glycolysis provides a net gain of __________. a. 2 ATP for the cell b. 4 ATP for the cell c. 36 ATP for the cell d. 38 ATP for the cell
a
Glycolysis occurs __________. a. whether or not oxygen is present b. only when oxygen is not present c. only when oxygen is present d. None of the listed responses is correct.
a
Glycolysis produces a net gain of __________ ATP molecules from each glucose molecule. a. 2 b. 4 c. 32 d. 36
a
High-density lipoproteins __________. a. are sometimes called "good cholesterol" b. deliver cholesterol to peripheral tissues c. deliver cholesterol to the spleen d. All of the listed responses are correct.
a
LDLs are absorbed by cells through the process of __________. a. receptor-mediated endocytosis b. facilitated diffusion c. active transport d. simple diffusion
a
Lipids circulate through the bloodstream as __________. a. lipoproteins and free fatty acids b. polyunsaturated fat c. saturated fats d. unsaturated fats
a
Phoebe grew up in Alaska's interior and used to play with her friends at recess in temperatures of −20°F. In fact, her school was not canceled until the temperatures reached −50°F. Which of the following terms describes her adaptation to Alaska's frigid winter climate? a. acclimatization b. convection c. radiation d. perspiration
a
The breakdown of fatty acid molecules into two carbon fragments is called __________. a. beta-oxidation b. coenzyme Q c. lipolysis d. the TCA cycle
a
The enzyme lipoprotein lipase __________. a. digests lipid complexes into free fatty acids and monoglycerides b. is necessary to form chylomicrons in the intestine c. digests high-density lipoproteins (HDLs) d. digests cholesterol into free fatty acids
a
Which of the following are coenzymes that deliver hydrogen ions and electrons to the ETS in the inner mitochondrial membrane? a. NADH and FADH2 b. acetyl CoA c. FADH2 d. NADH
a
Which of the following is NOT a nitrogen-containing compound found in the body? a. cholesterol b. purines c. amino acids d. pyrimidines
a
Which of the following is an important energy source during periods of starvation, when glucose supplies are limited? a. free fatty acids b. lipoproteins c. cholesterol d. glycerol
a
Why is hypervitaminosis involving water-soluble vitamins relatively UNCOMMON? a. Excessive amounts are readily excreted in the urine. b. Excessive amounts are stored in the bones. c. Excessive amounts are readily absorbed into skeletal muscle tissue. d. Excessive amounts are stored in adipose tissue.
a
Amino acids are deaminated and the amine group is ultimately excreted as __________. a. uric acid b. urea c. ammonia d. uroglobulin
b
Catabolism __________. a. produces ATP and heat b. both produces ATP and heat and breaks down organic molecules c. synthesizes new organic molecules d. breaks down organic molecules
b
In glycolysis, six-carbon glucose molecules are broken down into two three-carbon molecules of __________. a. oxaloacetic acid b. pyruvic acid c. acetyl-CoA d. citric acid
b
Which of the following individuals does NOT need to modify his or her daily activities to help regulate cholesterol levels? a. a 40-year old man who weighs 185 pounds, has a cholesterol level of 250 mg/dL, and does have a history of atherosclerosis b. a 40-year-old woman who weighs 135 pounds, has a total cholesterol level of 150 mg/dL, and does not have a history of atherosclerosis c. a 40-year-old woman who weighs 200 pounds, has a cholesterol level of 235 mg/dL, and does not have a history of atherosclerosis d. None of these individuals needs to modify his or her daily activities.
b
Which of the following selections includes ONLY essential amino acids for a growing child? a. proline, serine, cysteine, glutamine, histidine b. leucine, lysine, valine, tryptophan, arginine c. aspartic acid, glutamic acid, tyrosine, glycine, alanine d. valine, tyrosine, leucine, serine, alanine
b
Which of the following statements about hypervitaminosis is FALSE? a. Hypervitaminosis involving vitamin D can cause fatigue, weight loss, and potentially severe damage to the kidneys and cardiovascular system. b. Hypervitaminosis is often caused by a deficiency of fat-soluble vitamins. c. Hypervitaminosis involving vitamin A can cause nausea, dizziness, lethargy, and even death. d. All of the listed responses are correct.
b
Which of the following statements describes a factor that does NOT contribute to thermoregulatory problems in infants? a. Infants cannot shiver. b. The presence of brown fat impairs circulation to the skin. c. At birth, temperature-regulating mechanisms are not fully functional. d. Infant body temperature is more unstable than that of adults.
b
Which of the following statements is FALSE concerning basal metabolic rate (BMR) and thermoregulation? a. Assuming average catabolism of carbohydrates, proteins, and lipids, for each liter of oxygen a person consumes, 4.825 calories are generated. b. The average person has a BMR of 3000 calories per day. c. A simple way to determine an individual's BMR is to monitor respiratory activity. d. Individuals who lose body heat rapidly have higher BMRs than those who do not
b
Which type of lipid is linked to cholesterol deposition in arterial walls and may require a change in diet to control? a. high-density lipoproteins (HDLs) b. low-density lipoproteins (LDLs) c. very low-density lipoproteins (VLDLs) d. chylomicrons
b
Why is it that fatty acids and many amino acids CANNOT be converted to glucose? a. They are not used for energy production. b. Their catabolic pathways produce acetyl-CoA. c. Other organic molecules cannot be converted to glucose. d. Glucose is necessary to start the metabolic processes
b
Before the large vitamin B12 molecule can be absorbed, it must be bound to __________. a. another water-soluble vitamin b. the gastric epithelium c. vitamin C d. intrinsic factor
d
Carbohydrate depletion followed by carbohydrate loading __________. a. is a practice athletes sometimes use to obtain the maximum levels of ATP from carbohydrates before an athletic event b. involves exercising to exhaustion up to three days before an athletic event c. can be harmful to the muscles and kidneys d. All of the listed responses are correct.
d
Essential amino acids __________. a. consumed in the diet could lead to diseases such as pellagra or kwashiorkor b. can be produced in sufficient numbers for children, but not for adults c. are made in the body by an essential process called amination d. cannot be synthesized in the human body and cannot be synthesized in sufficient amounts for children
d
For each glucose molecule processed during aerobic cellular respiration, the cell gains __________. a. 4 molecules of ATP b. 24 molecules of ATP c. 32 molecules of ATP d. 36 molecules of ATP
d
How does neural tissue normally respond during the postabsorptive state? a. Neural tissue begins to absorb fatty acids and glycerol from the bloodstream. b. Neural tissue begins to break down glycogen reserves to produce glucose. c. Neural tissue begins to break down its lipid reserves as a result of the stimulation of epinephrine, glucocorticoids, and growth hormone. d. In the postabsorptive state, the activities of neural tissue do not change in comparison to its activities in the absorptive state.
d
If excess glucose still remains in the circulation after glycogen formation, the hepatocytes use glucose to __________. a. repair tissues b. regulate metabolism c. provide energy d. synthesize triglycerides
d
Metabolism refers to __________. a. only the intake of sodium in foods and the loss of sodium in sweat and tears b. only the digestion of foods and production of wastes c. only the balance between drinking water and sweating d. all the chemical reactions in the body
d
Milk and eggs are complete proteins because they contain __________. a. all the essential fatty acids and amino acids b. the recommended intake for vitamin B12 c. more protein than fat d. all the essential amino acids in sufficient quantities
d
Which of the following is NOT a mechanism for heat loss? a. inhibition of the vasomotor center causing peripheral vasodilation and the flow of warm blood to the surface of the body b. stimulation of sweat glands and their secretory output c. stimulation of the respiratory centers, leading to deeper respiration d. diminishing activity in the sympathetic vasomotor center
d
Which of the following is a fat-soluble vitamin necessary for synthesis of visual pigments? a. vitamin C b. vitamin K c. vitamin D d. vitamin A
d
Which of the following people would be in positive nitrogen balance? a. a pregnant woman b. athletes in training c. growing children d. All of the listed responses are correct.
d
Why can lipogenesis use almost any organic substrate? a. Lipid molecules contain carbon, hydrogen, and oxygen. b. Lipids can be converted and channeled directly into the Krebs cycle. c. Triglycerides are the most abundant lipids in the body. d. Lipids, amino acids, and carbohydrates can be converted to acetyl-CoA.
d
Why is it that lipids CANNOT provide large amounts of adenosine triphosphate (ATP) in a short period of time? a. Most lipids are processed in mitochondria, and mitochondrial activity is limited by the availability of oxygen. b. Lipids are insoluble, and it is difficult for water-soluble enzymes to reach them. c. Lipid reserves are difficult to mobilize. d. All of the listed responses are correct.
d