Chapter 23 - Metabolism
The vitamin that plays a role in maintaining epithelia and is required for the synthesis of visual pigments is vitamin A. B. C. D. E.
A
Most of the ATP from metabolism is produced in the electron transport system. mitochondrial matrix. citric acid cycle. cytosol. glycolysis.
electron transport system
The study of the flow of energy and its transformations is called thermodynamics. energetics. cellular respiration. metabolism. glycolysis.
energetics
Fatty acids that are necessary for proper health but cannot be synthesized by the body are called ________ fatty acids. non-metabolic vital oxidative metabolic essential
essential
Linoleic acid and linolenic acid are examples of transport proteins. essential amino acids. essential fatty acids. vitamins. lipoproteins.
essential fatty acids
The loss of heat energy by vaporizing water is called conduction. transmission. convection. evaporation. radiation.
evaporation
The nutrients that yield the most energy per gram when metabolized are nucleic acids. fats. vitamins. proteins. carbohydrates.
fats
The vitamin that is a coenzyme in amino acid and nucleic acid metabolism is folic acid (folate). pantothenic acid. vitamin K. pyridoxine (B6). vitamin C.
folic acid
Glucose: is absorbed and converted to pyruvate as needed by the liver. is transported to the liver by way of the hepatic portal vein. leaves the cytosol of the epithelial cells and reaches the interstitial fluid by simple diffusion. is generally used for catabolism after protein and lipid sources are used.
is transported to the liver by way of the hepatic portal vein
The sum of all of the biochemical processes going on within the human body at any given time is called metabolism. glycolysis. anabolism. oxidative phosphorylation. catabolism.
metabolism
Each cytochrome contains a(n) metal ion. lipoprotein. inorganic salt. ATP synthase. All of the answers are correct.
metal ion
ganic ions released through the dissociation of electrolytes are called trace minerals. minerals. nutrients. vitamins. free radicals.
minerals
Reactions within ________ provide most of the energy needed by a typical cell. the endoplasmic reticulum the mitochondria cytoplasm nucleus the plasma membrane
mitochondria
The citric acid cycle occurs in the golgi apparatus. cytosol. mitochondrial matrix. ribosome. mitochondrial intermembrane space.
mitochondrial matrix
Catabolism of protein is not a practical source of quick energy because of all of the following except that one of the by-products of protein catabolism is ammonia. most individuals have little protein to spare before harming vital organs. proteins are more difficult to break apart than lipids or carbohydrates. extensive catabolism of protein threatens homeostasis. the energy yield from protein is less than the yield from lipids.
most individuals have little protein to spare before harming vital organs
In oxidative phosphorylation, energy for the synthesis of ATP is directly obtained from the splitting of oxygen molecules. combination of two atoms of hydrogen and one atom of oxygen to form water. movement of hydrogen ions through channels in the inner mitochondrial membrane. oxidation of acetyl-CoA. breaking of the covalent bonds in glucose.
movement of hydrogen ions through channels in the inner mitochondrial membrane.
During starvation, carbohydrate reserves maintained by metabolizing inorganic compounds. there is a decline in circulating ketone bodies. muscle proteins are used as an energy source. carbohydrate utilization increases. gluconeogenesis ceases.
muscle proteins are used as an energy source
The vitamin that is part of the coenzyme NAD is thiamine. riboflavin. niacin. folic acid (folate). cobalamin.
niacin
A T4 assay is used to monitor the energy efficiency of metabolism. directly measure the basal metabolic rate. determine the amount of oxygen consumed during metabolism. determine the number of calories in food. obtain an index of metabolic activity.
obtain an index of metabolic acitivity
The ________ of the mitochondrion contains large-diameter pores that are permeable to ions and small organic molecules such as pyruvic acid. inner membrane matrix cristae plasma membrane outer membrane
outer membrane
Nitrogen compounds of the body include all of the following except porphyrin. oxaloacetate. amino acids. creatine. purines.
oxaloacetate
________ creates 90 percent of the ATP normally generated. Glycogenesis Gluconeogenesis Beta oxidation Oxidative phosphorylation Glycolysis
oxidative phosphorylation
The citric acid cycle is an aerobic process because FADH2 is produced. citric acid molecules have oxygen atoms. oxygen is needed to remove carbon atoms as carbon dioxide. NAH+ is converted into NADH. ADP is phosphorylated.
oxygen is needed to remove carbon atoms as carbon dioxide.
The vitamin that is a constituent of coenzyme A is pyridoxine (B6). niacin. riboflavin. pantothenic acid. folic acid (folate).
pantothenic acid
The inherited metabolic disorder that results from the accumulation of phenylketones from phenylalanine is acidosis. ketosis. kwashiorkor. marasmus. phenylketonuria.
phenylketonuria
n ion that is a necessary component of high-energy compounds and nucleic acids and a structural component of bone is the ________ ion. iodide bicarbonate chloride phosphate sulfate
phosphate
Factors that influence an individual's BMR (basal metabolic rate) include all of the following except gender. genetics. physical exertion. body weight. age.
physical exertion
When the body is relying on internal energy reserves to continue meeting its energy demands, it is in the ________ state. postabsorptive starvation absorptive preabsorptive deprivation
postabsorptive
The major cation in cytoplasm is magnesium. calcium. iron. potassium. sodium.
potassium
Lipids provide energy for cells with modest energy demands. yield quick bursts of energy. deliver somewhat less energy than an equivalent mass of glucose. are difficult to store since they are not water soluble. are the primary nutrient metabolized in cells.
provide energy for cells with modest energy demands
In an environment that is cooler than your body, you lose heat in a process called convection. evaporation. conduction. thermal regulation. radiation.
radiation
More than half the heat is lost from the body indoors through the process of evaporation. convection. concentration. conduction. radiation.
radiation
When NAD+ is ________ it becomes NADH. When NADH is ________ it becomes NAD+. phosphorylated; dephosphorylated phosphorylated; deaminated reduced; oxidized oxidized; reduced made; recycled
reduced;oxidized
The function of the citric acid cycle is to remove hydrogen atoms from organic molecules and transfer them to coenzymes. hydrolyze glucose in the presence of oxygen to obtain two pyruvate molecules. produce carbon dioxide to balance the oxygen requirement for cellular respiration. transfer the acetyl group gained from glycolysis to molecules of pyruvate. produce water.
remove hydrogen atoms from organic molecules and transfer them to coenzymes
The vitamin that is part of the coenzymes FAD is thiamine. riboflavin. niacin. folic acid (folate). cobalamin.
riboflavin
In order to determine the LDL level in a patient's blood, it is necessary to measure total cholesterol level. triglyceride and monoglyceride levels. triglyceride level. total cholesterol level, HDL level, and triglyceride level. HDL level.
total cholesterol level, HDL and triglyceride
In transamination, the amino group of an amino acid is absorbed by water. converted to urea. converted to ammonia. transferred to acetyl-CoA. transferred to a keto acid.
transferred to a keto acid
What is the role of NADH in metabolism? produce bicarbonate ions for a pH buffer phosphorylate ADP into ATP produce carbon dioxide transport hydrogen atoms to coenzymes convert pyruvic acid into acetyl-coA
transport hydrogen atoms to coenzymes
During lipolysis, triglycerides are converted into molecules of acetyl-CoA. lipids are metabolized to yield ATP. lipids are formed from excess carbohydrates. lipids are converted into glucose molecules. triglycerides are broken down into glycerol and fatty acids.
triglycerides are broken down into glycerol and fatty acid
The conversion of ammonia into a less toxic substance produces nitrate. ketone bodies. acetyl-CoA. urea. water.
urea
Impaired fat absorption in the intestine would interfere with the absorption of vitamin A. vitamin B12. vitamin C. riboflavin. niacin.
vitamin A
The element that is necessary for the proper function of the enzyme carbonic anhydrase is zinc. iron. cobalt. selenium. iodine.
zinc
What percent of energy released from catabolism is lost as heat? 60 30 50 40 20
60
For adults, there are ________ essential amino acids that cannot be synthesized by the human body. 8 10 2 6 20
8
In glycolysis, each molecule of glucose that is catabolized gives a net yield of how many molecules of ATP? 36 30 2 4 38
2
The chemical equation that correctly summarizes the overall reaction in oxidative phosphorylation is 2 H2 + O2 → 2 H2O. P + 3 O → PO3. H2 + O2 → H2O. H2 + O2 → H2O + O. 3 H2 + 2O2 → 3 H2O + 2 O.
2 H2 + O2 → 2 H2O.
Obesity is defined as a body weight more than ________ percent above the ideal body weight for an individual. 20 15 10 5 30
20
If 8 molecules of NADH from the citric acid cycle entered the ETS, how much ATP would be produced? 36 ATP 8 ATP 32 ATP 3 ATP 24 ATP
24 ATP
Hydrogen atoms from one FADH2 from the citric acid cycle produce how much ATP in the electron transport system? 32 ATP 1 ATP 4 ATP 2 ATP 3 ATP
2ATP
How many net ATP molecules are produced by the complete metabolism (all pathways) of one glucose molecule? 2 ATP 500 ATP 32 ATP 36 ATP 63 ATP
36
According to the Dietary Guidelines for Americans, there are ________ basic food groups. 7 3 6 5 4
5
Removal of the amino group from amino acids in the first step of their catabolism requires a coenzyme derived from vitamin A. C. B9. B12. B6.
B6
The end products of aerobic respiration are oxygen and water. pyruvic acid and carbon dioxide. NADH and FADH2. carbon dioxide and alcohol. carbon dioxide, water, and ATP.
carbon dioxide, water, ATP
The end products of glycolysis are NADH and FADH2. ATP, water, and carbon dioxide. pyruvic acid and citric acid. ATP, NADH, and pyruvic acid. ADP and ATP.
ATP NADH and pyruvic acid
An excess of which water-soluble vitamin results in polycythemia? B12 (cobalamin) B2 (riboflavin) B3 (niacin) B6 (pyroxidine)
B12
A vitamin obtained that is a coenzyme in amino acid and lipid metabolism is pyridoxine (B6). riboflavin. thiamine. folic acid (folate). niacin.
B6
The ________ represents the minimum resting energy expenditures of an awake, alert individual. basal metabolic rate heart rate heat loss quotient blood pressure All of the above
BMR
Which of the following statements regarding brown fat is false? Brown fat contains a rich vascular supply. Brown fat is found in infants. Brown fat is innervated by the sympathetic nervous system. Brown fat functions in nonshivering thermogenesis. Brown fat is concentrated around visceral organs in the adult.
Brown fat is concentrated around visceral organs in the adult.
Inadequate exposure to sunlight could result in decreased amounts of vitamin ________ in the body. A B12 C D E
D
The vitamin that is required for proper bone growth and for calcium absorption and retention is vitamin A. B. C. D. E.
D
The vitamin that prevents breakdown of vitamin A and fatty acids is vitamin A. B. C. D. E.
E
Someone with a total cholesterol level above their optimal range should reduce the amount of saturated fat in the diet. lose weight if overweight. modify their diet. have annual checkups. All of the answers are correct.
all are correct
The Dietary Guidelines for Americans recommends many servings a day of dark-green and orange vegetables. Which vitamin is particularly abundant in this food group? A folic acid E C All of the answers are correct.
all are correct
________ carry excess cholesterol from peripheral tissues to the liver. Intermediate-density lipoproteins (IDLs) Very-high-density lipoproteins (VHDLs) Very-low-density lipoproteins (VLDLs) Low-density lipoproteins (LDLs) High-density lipoproteins (HDLs)
HDLs
The vitamin that is essential for the production of several clotting factors is vitamin A. B. K. E. C.
K
Lipoproteins that carry mostly cholesterol to peripheral tissues are called very-low-density lipoproteins. intermediate-density lipoproteins. high-density lipoproteins. chylomicrons. low-density lipoproteins.
LDLs
Which is true regarding lipoproteins and lipid transport and distribution? Capillary walls contain the enzyme lipoprotein lipase, which breaks down the triglycerides. The liver absorbs triglycerides and removes the chylomicrons. The HDLs return the unused cholesterol to the liver, where it is extracted and packaged in new LDLs or excreted with bile salts in bile. The liver releases high-density lipoproteins (HDLs) into the circulation, which deliver cholesterol to peripheral tissues.
The HDLs return the unused cholesterol to the liver, where it is extracted and packaged in new LDLs or excreted with bile salts in bile.
The heat-gain center for thermoregulation activates skin vasoconstriction. resides in the pre-optic hypothalamus. activates nonshivering thermogenesis. activates shivering thermogenesis. All of the answers are correct.
all are correct
n the ETS, ________ accepts electrons from one molecule and transfers them to another. a coenzyme a hydrogen ion ADP the acetyl group NAD
a coenzyme
Which of the following individuals would lose heat the fastest in a cold room? an adult woman a newborn infant a child an adult man an adolescent male
a newborn infant
Assuming they all weigh the same and maintain the same body temperature, which of the following would lose heat the fastest? a tall, very slender person a person of average build a short, thickly built person None of the answers is correct; they would lose heat at an equal rate.
a tall very slender person
Compounds that cells can use to make glucose include all of the following, except some amino acids. glycerol. acetyl-CoA. lactate. pyruvate.
acetyl CoA
In order for glycolysis to proceed, which of the following need not be present? ADP NAD glucose ATP acetyl-CoA
acetyl-CoA
Lipogenesis generally begins with fatty acids. amino acids. glucose. succinyl-CoA. acetyl-CoA.
acetyl-CoA
A balanced diet should contain adequate amounts of water. include adequate substrates for the production of energy. contain adequate amounts of vitamins and minerals. provide essential amino acids and fatty acids. All of the answers are correct.
all are correct
Cells perform catabolism to generate ATP, which can be used for protein synthesis. muscle contraction. ion transport. glycogen synthesis. All of the answers are correct.
all are correct
Cells synthesize new organic components for which of the following reasons? produce secretions structural maintenance store nutrients growth and repair All of the answers are correct.
all are correct
During glycolysis, four molecules of ATP are produced. hydrogen atoms are removed from organic molecules. a molecule of glucose is converted into two molecules of pyruvic acid. two molecules of ATP are consumed. All of the answers are correct.
all are correct
In the electron transport chain, reduced molecules transfer energy to ATP formation. oxidative phosphorylation leads to ATP formation. NADH and FADH2 donate hydrogen atoms. generates a concentration gradient by pumping hydrogen ions. All of the answers are correct.
all are correct
In the human body, cholesterol is important because it is a key constituent of bile. helps waterproof the epidermis. is a lipid component of all cell membranes. is the precursor of several steroid hormones and vitamin D3. All of the answers are correct.
all are correct
On a tour of African countries, Mark contracts a bad case of traveler's diarrhea. Because he can't eat very much, his body starts to use energy sources other than carbohydrates. This would result in increased levels of urea in the blood. increased gluconeogenesis in the liver. lipid metabolism. ketosis and a decreased blood pH. All of the answers are correct.
all are correct
Metabolism of amino acids in the citric acid cycle yields approximately the same energy as carbohydrate metabolism. more energy than lipid and carbohydrate metabolism combined. more energy than lipid metabolism. approximately the same energy as lipid metabolism. more energy than carbohydrate metabolism.
approximately the same energy as carbohydrate metabolism
A(n) ________ diet contains all of the ingredients necessary to maintain homeostasis. essential balanced complete vegan metabolic
balanced
The citric acid cycle consumes two moles of carbon dioxide. begins with the formation of a molecule of citric acid. directly produces most of the ATP from the catabolism of glucose. forms acetyl-CoA from glucose-6-phosphate. contains enzymes called cytochromes.
begins with the formation of a molecule of citric acid
All of the following occur when the temperature of the preoptic area of the hypothalamus drops below its thermostat setting except nonshivering thermogenesis occurs. blood returning from limbs is shunted to deep veins. epinephrine levels rise. blood flow to the skin increases. shivering thermogenesis occurs.
blood flow to the skin increases
A cation that is essential for muscle contraction, nerve function, and blood clotting is selenium. potassium. sodium. magnesium. calcium.
calcium
The strategy of eating starchy foods for several days before an athletic event is known as the Atkins diet. carbohydrate craving. overeating. glycolysis reaction. carbohydrate loading.
carbohydrate loading
The major anion in body fluids is bicarbonate. sulfate. iodide. chloride.
chloride
Lipoproteins that are formed within the intestinal epithelium to transfer dietary fats into circulation are called intermediate-density lipoproteins. very-low-density lipoproteins. high-density lipoproteins. chylomicrons. low-density lipoproteins.
chylomicrons
The lipoproteins that carry absorbed lipids from the intestinal tract to the bloodstream are HDLs. coenzymes. LDLs. VLDLs. chylomicrons.
chylomicrons
________ are the largest lipoproteins, ranging in diameter up to 0.5 µm, produced by intestinal epithelial cells from the fats in food. High-density lipoproteins (HDLs) Low-density lipoproteins (LDLs) Very-low-density lipoproteins (VLDLs) Chylomicrons Intermediate-density lipoproteins (IDLs)
chylomicrons
In the citric acid cycle, a 2 carbon molecule and a 4 carbon molecule combine to produce NADH. citric acid. carbon dioxide. fructose-1, 6-bisphosphate. pyruvic acid.
citric acid
Oxygen is an important molecule in which of the following? citric acid cycle only glycolysis only citric acid cycle and ETS ETS only glycolysis, citric acid cycle, and ETS
citric acid cycle and ETS
A(n) ________ protein contains all of the essential amino acids. phosphorylated complete incomplete vital real
complete
The direct transfer of heat energy from one object to another through physical contact is called conduction. evaporation. transmission. convection. radiation.
conduction
Heat loss to the cooler air that moves across the surface of your body is called conduction. convection. transmission. radiation. evaporation.
convection
The trace element needed as a cofactor for hemoglobin synthesis is iodine. copper. cobalt. zinc. silicon.
copper
During the postabsorptive state, ________ stimulate(s) lipid catabolism. androgens glucocorticoids glucagon insulin All of the answers are correct.
glucocorticoids
In the postabsorptive state of metabolic activity: glucocorticoids stimulate the mobilization of lipid and protein reserves. glucagon inhibits glycogenolysis and gluconeogenesis, primarily in the liver. androgens, estrogens, and growth hormone also stimulate protein synthesis. insulin stimulates triglyceride synthesis.
glucocorticoids stimulate the mobilization of lipid and protein reserves
Fatty acids and many amino acids cannot be used for ________ because their catabolic pathways produce acetyl-CoA. glycolysis glycogenesis gluconeogenesis glycemia cellular respiration
gluconeogenesis
The process of synthesizing glucose from noncarbohydrates is called glycogenesis. cellular respiration. glycemia. gluconeogenesis. glycolysis.
gluconeogenesis
Although other nutrients can feed into the citric acid cycle, ________ yields energy the quickest. glucose fat glycogen an amino acid protein
glucose
Gluconeogenesis is the synthesis of ________ from noncarbohydrate precursors, such as lactate, glycerol, or amino acids. glycogen glucagon glycerides glucose
glucose
The process of glycogen formation is known as glycolysis. cellular respiration. glycemia. gluconeogenesis. glycogenesis.
glycogenesis
A high uric acid level (above 7.4 mg/dl) can lead to the painful condition known as anorexia nervosa. lupus. ketosis. rheumatoid arthritis. gout.
gout
The condition when excessive fluid loss from sweating disrupts thermoregulatory mechanisms is known as hydrosis. heat exhaustion. hypothermia. heat stroke. thermoneogenesis.
heat exhaustion
A(n) ________ protein is deficient in one or more of the essential amino acids. phosphorylated complete real vital incomplete
incomplete
Wally decides to go on a hunger strike to further one of his favorite causes. After many days with nothing but water, you would not expect to observe elevated levels of glucocorticoids. ketone bodies in his urine. increased insulin secretion. decreased blood pH. All of the answers are correct.
increased insulin secretion
All of the following complement the actions of glucocorticoids in the postabsorptive state except glucagon. insulin. epinephrine. growth hormone.
insulin
Lipoproteins that are intermediate in size and lipid composition between VLDLs and LDLs are called low-density lipoproteins. very-low-density lipoproteins. intermediate-density lipoproteins. high-density lipoproteins. chylomicrons.
intermediate-density lipoproteins
An element that is a component of hemoglobin, myoglobin, and cytochromes is calcium. zinc. magnesium. iron. cobalt. SubmitM
iron
Convection: is the direct transfer of energy through physical contact. changes a liquid to a vapor. is energy similar to radiant heat from the sun. is the result of conductive heat loss to the air that overlies the surface of the body.
is the result of conductive heat loss to the air that overlies the surface of the body
Why is glucose the primary energy source for cells? Glycogenolysis occurs very quickly, even though it is a very complex pathway. Glycolysis provides a large amount of ATP. It can be efficiently stored as glycogen, which forms compact, insoluble granules. Glucose is a large, insoluble molecule.
it can be efficiently stored as glycogen, which forms compact, insoluble granules
The presence of ketone bodies in the urine is known as uremia. polyuria. hematuria. ketosis. ketonuria.
ketonuria
The energy content of foods is commonly given in units of moles. kilograms. kilocalories. ounces. grams.
kilocalories
All of the following occur during the postabsorptive state except that gluconeogenesis occurs in the liver. levels of blood glucose are elevated. ketone bodies may be formed. fat mobilization occurs. glycogenolysis occurs in the liver.
levels of blood glucose are elevated
The essential fatty acids are cholesterol and glycerol. HDLs and LDLs. linoleic acid and linolenic acid. glycerol and pyruvic acid. leucine and lysine.
linoleic acid and linolenic acid.
All of the following are true of beta-oxidation except that it occurs in the mitochondria. fatty acids break down into two-carbon fragments. lipids are converted into glycogen molecules. it requires coenzyme A, NAD, and FAD. it yields large amounts of ATP.
lipids are converted into glycogen molecules
Most of the nutrients that have been absorbed by the digestive tract end up at the ______, wherein nutrients are absorbed as needed to maintain normal levels in the systemic circuit. jejunum of the small intestine peripheral tissues large intestine liver
liver
Urea is formed in the stomach. small intestine. liver. large intestine. kidneys.
liver
A cation that often acts as a cofactor for enzymes is sodium. magnesium. calcium. zinc. potassium.
magnesium
The term ________ refers to an unhealthy state resulting from inadequate intake of one or more nutrients that becomes life-threatening as the deficiencies accumulate. maladaptation purging malnutrition binging malabsorption
malnutrition
Which of the following basic food groups provides complete proteins? fruits meat and beans vegetables grains
meat and beans
When the temperature of the preoptic area of the hypothalamus exceeds its thermostat setting, peripheral vasoconstriction occurs. rate and depth of respiration decreases. blood is shunted to deep veins. sweat glands are inhibited. skin blood flow increases.
skin blood flow increases
The major cation in extracellular fluid is magnesium. potassium. sodium. iron. calcium.
sodium
The main purpose of the citric acid cycle is to produce Acetyl CoA so that the citric acid cycle can continue. supply hydrogen atoms to the Electron Transport System. produce citric acid to make vitamin C in the mitochondria. phosphorylate glucose molecules. produce proteins for energy storage.
supply hydrogen atoms to the ETC
The major steps in oxidative phosphorylation include all of the following except ionization of hydrogen atoms. the breaking of carbon-carbon covalent bonds. removal of hydrogen atoms from a substrate molecule by coenzymes. decreasing the energy level of electrons passing through the electron transport chain. the acceptance of electrons by oxygen atoms.
the breaking of carbon-carbon covalent bonds
The carbon dioxide of respiration is formed during the formation of water. glycolysis. the citric acid cycle. the formation of pyruvic acid. electron transport.
the citric acid cycle
During the absorptive state, the liver forms glycogen. skeletal muscle fibers release glucose. insulin levels are low. skeletal muscle breaks down glycogen. adipocytes release fatty acids to the circulation.
the liver forms glycogen
Which of the following statements regarding amino acid metabolism is true? Liver cells must break down urea, a toxic compound. The removal of the amino group is the first step in amino acid catabolism. The body synthesizes all of the 10 essential amino acids. When broken down in the mitochondrion, the energy yield of an amino acid is negligible.
the removal of the amino group is the first step in aa catabolism
The term ________ refers to the homeostatic process that allows us to maintain a constant body temperature. thermoregulation thermochemistry thermogenesis thermography thermodynamics
thermoregulation
The vitamin whose deficiency causes beriberi is thiamine. riboflavin. niacin. folic acid (folate). cobalamin.
thiamine