5) What is the role of NADH in metabolism?
A) convert pyruvic acid into acetyl-coA
B) produce bicarbonate ions for a pH buffer
C) transport hydrogen atoms to coenzymes
D) produce carbon dioxide
E) phosphorylate ADP into ATP

C) transport hydrogen atoms to coenzymes

6) When NAD+ is ________ it becomes NADH. When NADH is ________ it becomes NAD+.
A) phosphorylated; deaminated
B) reduced; oxidized
C) made; recycled
D) phosphorylated; dephosphorylated
E) oxidized; reduced

B) reduced; oxidized

7) All the available nutrient molecules distributed in the blood form a
A) nutrient storehouse.
B) nutrient reserve.
C) nutrient pool.
D) energy reserve.
E) organic storehouse.

C) nutrient pool.

8) Intermediary molecules that accept electrons and transfer them to another molecule are called
A) nutrients.
B) organics.
C) ketones.
D) metabolites.
E) coenzymes.

E) coenzymes.

9) The chemical equation that correctly summarizes the overall reaction in oxidative phosphorylation is
A) H2 + O2 → H2O + O.
B) 2 H2 + O2 → 2 H2O.
C) 3 H2 + 2O2 → 3 H2O + 2 O.
D) H2 + O2 → H2O.
E) P + 3 O → PO3.

B) 2 H2 + O2 → 2 H2O.

10) The function of the citric acid cycle is to
A) remove hydrogen atoms from organic molecules and transfer them to coenzymes.
B) transfer the acetyl group gained from glycolysis to molecules of pyruvate.
C) hydrolyze glucose in the presence of oxygen to obtain two pyruvate molecules.
D) produce carbon dioxide to balance the oxygen requirement for cellular respiration.
E) produce water.

A) remove hydrogen atoms from organic molecules and transfer them to coenzymes.

11) In the ETS, ________ accepts electrons from one molecule and transfers them to another.
A) a hydrogen ion
B) a coenzyme
C) the acetyl group
D) ADP
E) NAD

B) a coenzyme

12) In order for glycolysis to proceed, which of the following need not be present?
A) glucose
B) acetyl-CoA
C) ATP
D) NAD
E) ADP

B) acetyl-CoA

13) The ________ of the mitochondrion contains large-diameter pores that are permeable to ions
and small organic molecules such as pyruvic acid.
A) inner membrane
B) plasma membrane
C) outer membrane
D) matrix
E) cristae

C) outer membrane

14) All of the following occur during glycolysis, except
A) a molecule of glucose is converted into two molecules of pyruvic acid.
B) four molecules of ATP are produced.
C) two molecules of ATP are consumed.
D) hydrogen atoms are removed from organic molecules.
E) a molecule of carbon dioxide is produced.

E) a molecule of carbon dioxide is produced.

15) The citric acid cycle
A) begins with the formation of a molecule of citric acid.
B) directly produces most of the ATP from the catabolism of glucose.
C) consumes two moles of carbon dioxide.
D) contains enzymes called cytochromes.
E) forms acetyl-CoA from glucose-6-phosphate.

A) begins with the formation of a molecule of citric acid.

16) The carbon dioxide of respiration is formed during
A) glycolysis.
B) the citric acid cycle.
C) electron transport.
D) the formation of pyruvic acid.
E) the formation of water.

B) the citric acid cycle.

17) In glycolysis, each molecule of glucose that is catabolized gives a net yield of how many molecules of ATP?
A) 2
B) 4
C) 30
D) 36
E) 38

A) 2

18) The strategy of eating starchy foods for several days before an athletic event is known as
A) carbohydrate craving.
B) the Atkins diet.
C) carbohydrate loading.
D) glycolysis reaction.
E) overeating.

C) carbohydrate loading.

19) Although other nutrients can feed into the citric acid cycle, ________ yields energy the quickest.
A) glycogen
B) glucose
C) protein
D) fat
E) an amino acid

B) glucose

20) The major steps in oxidative phosphorylation include all of the following except
A) removal of hydrogen atoms from a substrate molecule by coenzymes.
B) ionization of hydrogen atoms.
C) decreasing the energy level of electrons passing through the electron transport chain.
D) the breaking of carbon-carbon covalent bonds.
E) the acceptance of electrons by oxygen atoms.

D) the breaking of carbon-carbon covalent bonds.

21) In oxidative phosphorylation, energy for the synthesis of ATP is directly obtained from the
A) splitting of oxygen molecules.
B) breaking of the covalent bonds in glucose.
C) movement of hydrogen ions through channels in the inner mitochondrial membrane.
D) combination of two atoms of hydrogen and one atom of oxygen to form water.
E) oxidation of acetyl-CoA.

C) movement of hydrogen ions through channels in the inner mitochondrial membrane.

22) How many net ATP molecules are produced by the complete metabolism (all pathways) of
one glucose molecule?
A) 2-4 ATP
B) 6 ATP
C) 30-32 ATP
D) 100-120 ATP
E) 150 ATP

C) 30-32 ATP

23) The citric acid cycle occurs in the
A) cytosol.
B) golgi apparatus.
C) mitochondrial intermembrane space.
D) mitochondrial matrix.
E) ribosome.

D) mitochondrial matrix.

24) Oxygen is an important molecule in which of the following?
A) citric acid cycle and ETS
B) glycolysis, citric acid cycle, and ETS
C) citric acid cycle only
D) glycolysis only
E) ETS only

A) citric acid cycle and ETS

25) The citric acid cycle is an aerobic process because
A) ADP is phosphorylated.
B) FADH2 is produced.
C) citric acid molecules have oxygen atoms.
D) oxygen is needed to remove carbon atoms as carbon dioxide.
E) NAH+ is converted into NADH.

D) oxygen is needed to remove carbon atoms as carbon dioxide.

26) The main purpose of the citric acid cycle is to
A) produce Acetyl CoA so that the citric acid cycle can continue.
B) produce proteins for energy storage.
C) phosphorylate glucose molecules.
D) supply hydrogen atoms to the Electron Transport System.
E) produce citric acid to make vitamin C in the mitochondria.

D) supply hydrogen atoms to the Electron Transport System.

27) The end products of aerobic respiration are
A) carbon dioxide, water, and ATP.
B) pyruvic acid and carbon dioxide.
C) carbon dioxide and alcohol.
D) oxygen and water.
E) NADH and FADH2.

A) carbon dioxide, water, and ATP.

28) Most of the ATP from metabolism is produced in the
A) citric acid cycle.
B) electron transport system.
C) cytosol.
D) mitochondrial matrix.
E) glycolysis.

B) electron transport system.

29) In the citric acid cycle, a 2 carbon molecule and a 4 carbon molecule combine to produce
A) fructose-1, 6-bisphosphate.
B) carbon dioxide.
C) pyruvic acid.
D) NADH.
E) citric acid.

E) citric acid.

30) The end products of glycolysis are
A) ATP, water, and carbon dioxide.
B) ATP, NADH, and pyruvic acid.
C) ADP and ATP.
D) pyruvic acid and citric acid.
E) NADH and FADH2.

B) ATP, NADH, and pyruvic acid.

31) The process of synthesizing glucose from noncarbohydrates is called
A) glycolysis.
B) gluconeogenesis.
C) cellular respiration.
D) glycemia.
E) glycogenesis.

B) gluconeogenesis.

32) The process of glycogen formation is known as
A) glycolysis.
B) gluconeogenesis.
C) cellular respiration.
D) glycemia.
E) glycogenesis.

E) glycogenesis.

33) Fatty acids and many amino acids cannot be used for ________ because their catabolic
pathways produce acetyl-CoA.
A) glycolysis
B) gluconeogenesis
C) cellular respiration
D) glycemia
E) glycogenesis

B) gluconeogenesis

34) Carbon and oxygen atoms are removed as carbon dioxide in a process called
A) anabolism.
B) decarboxylation.
C) deamination.
D) oxidative phosphorylation.
E) substrate-level phosphorylation.

B) decarboxylation.

35) The two most important coenzymes for glycolysis and the citric acid cycle are
A) ATP and ADP.
B) FAD and FMN.
C) NAD and ATP.
D) NAD and FAD.
E) ATP and GTP.

D) NAD and FAD.

36) During the citric acid cycle, both NAD and FAD ________ a hydrogen atom and become
________.
A) lose; oxidized
B) gain; oxidized
C) lose; reduced
D) gain; reduced
E) gain; ATP

D) gain; reduced

37) The formation of GTP from GDP in the citric acid cycle is an example of
A) substrate-level phosphorylation.
B) oxidative phosphorylation.
C) decarboxylation.
D) cellular respiration.
E) aerobic metabolism.

A) substrate-level phosphorylation.

38) The electron transport system doesn't produce ATP directly instead it uses the hydrogen ion gradient to drive
A) substrate-level phosphorylation.
B) chemiosmosis.
C) anaerobic metabolism.
D) decarboxylation.
E) deamination.

B) chemiosmosis.

39) Cyanide gas is lethal because it
A) inhibits the kinase that phosphorylates ATP.
B) inhibits the ATP synthase.
C) blocks substrate-level phosphorylation.
D) blocks the final electron acceptor in the ETS.
E) binds NAD preventing it from being reduced.

D) blocks the final electron acceptor in the ETS.

40) What is the molecule labeled "1"?
A) phosphoglyceric acid
B) citric acid
C) pyruvate
D) NADH
E) FADH2

C) pyruvate

41) What is the molecule labeled "2"?
A) hydrogen atoms
B) citric acid
C) NADH
D) carbon dioxide
E) FADH2

D) carbon dioxide

42) What is the substance labeled "4"?
A) hydrogen atoms
B) citric acid
C) 4 carbon molecule
D) NADH
E) FADH2

A) hydrogen atoms

43) What is the molecule labeled "7"?
A) hydrogen atoms
B) citric acid
C) 4 carbon molecule
D) NADH
E) FADH2

C) 4 carbon molecule

44) What is the molecule labeled "3"?
A) ADP
B) carbon dioxide
C) NADH
D) hydrogen atoms
E) pyruvate

C) NADH

45) The lipoproteins that carry absorbed lipids from the intestinal tract to the bloodstream are
A) HDLs.
B) VLDLs.
C) LDLs.
D) chylomicrons.
E) coenzymes.

D) chylomicrons.

46) During lipolysis,
A) triglycerides are converted into molecules of acetyl-CoA.
B) triglycerides are broken down into glycerol and fatty acids.
C) lipids are converted into glucose molecules.
D) lipids are formed from excess carbohydrates.
E) lipids are metabolized to yield ATP.

B) triglycerides are broken down into glycerol and fatty acids.

47) All of the following are true of beta-oxidation except that
A) it occurs in the mitochondria.
B) fatty acids break down into two-carbon fragments.
C) lipids are converted into glycogen molecules.
D) it requires coenzyme A, NAD, and FAD.
E) it yields large amounts of ATP.

C) lipids are converted into glycogen molecules.

48) Lipids
A) deliver somewhat less energy than an equivalent mass of glucose.
B) are difficult to store since they are not water soluble.
C) yield quick bursts of energy.
D) provide energy for cells with modest energy demands.
E) are the primary nutrient metabolized in cells.

D) provide energy for cells with modest energy demands.

49) Lipogenesis generally begins with
A) glucose.
B) amino acids.
C) fatty acids.
D) acetyl-CoA.
E) succinyl-CoA.

D) acetyl-CoA.

50) Linoleic acid and linolenic acid are examples of
A) transport proteins.
B) lipoproteins.
C) essential fatty acids.
D) essential amino acids.
E) vitamins.

C) essential fatty acids.

51) In order to determine the LDL level in a patient's blood, it is necessary to measure
A) total cholesterol level.
B) HDL level.
C) triglyceride level.
D) triglyceride and monoglyceride levels.
E) total cholesterol level, HDL level, and triglyceride level.

E) total cholesterol level, HDL level, and triglyceride level.

52) ________ are the largest lipoproteins, ranging in diameter up to 0.5 μm.
A) Very-low-density lipoproteins (VLDLs)
B) Low-density lipoproteins (LDLs)
C) Micelles
D) High-density lipoproteins (HDLs)
E) Chylomicrons

E) Chylomicrons

53) ________ carry excess cholesterol from peripheral tissues to the liver.
A) Very-low-density lipoproteins (VLDLs)
B) Low-density lipoproteins (LDLs)
C) Micelles
D) High-density lipoproteins (HDLs)
E) Very-high-density lipoproteins (VHDLs)

D) High-density lipoproteins (HDLs)

54) Fatty acids that are necessary for proper health but cannot be synthesized by the body are called ________ fatty acids.
A) oxidative
B) metabolic
C) essential
D) vital
E) non-metabolic

C) essential

55) Lipoproteins that are formed within the intestinal epithelium to transfer dietary fats into
circulation are called
A) chylomicrons.
B) very-low-density lipoproteins.
C) micelles.
D) low-density lipoproteins.
E) high-density lipoproteins.

A) chylomicrons.

56) Lipoproteins that are primarily sent to skeletal muscles and adipose tissues are called
A) chylomicrons.
B) very-low-density lipoproteins.
C) micelles.
D) low-density lipoproteins.
E) high-density lipoproteins.

B) very-low-density lipoproteins.

57) Lipoproteins that carry mostly cholesterol to peripheral tissues are called
A) chylomicrons.
B) very-low-density lipoproteins.
C) micelles.
D) low-density lipoproteins.
E) high-density lipoproteins.

D) low-density lipoproteins.

58) The complete catabolism of fatty acids is through the process called
A) lipogenesis.
B) glycolysis.
C) beta-oxidation.
D) glycogenolysis.
E) adipogenesis.

C) beta-oxidation.

59) Lipogenesis is common for organic molecules because the intermediate ________ is formed in most nutrient metabolic processes.
A) pyruvate
B) acetyl-CoA
C) glycerol
D) glucose
E) lipoprotein

B) acetyl-CoA

60) Lipoproteins are water-soluble because of a superficial coating of
A) cholesterol.
B) bile salts.
C) phospholipids and proteins.
D) triglycerides.
E) glycerol.

C) phospholipids and proteins.

61) Removal of the amino group from amino acids in the first step of their catabolism requires a coenzyme derived from vitamin
A) A.
B) C.
C) B12.
D) B6.
E) B9.

D) B6.

62) In transamination, the amino group of an amino acid is
A) converted to ammonia.
B) converted to urea.
C) transferred to a keto acid.
D) absorbed by water.
E) transferred to acetyl-CoA.

C) transferred to a keto acid.

63) The conversion of ammonia into a less toxic substance produces
A) ketone bodies.
B) urea.
C) nitrate.
D) acetyl-CoA.
E) water.

B) urea.

64) Urea is formed in the
A) liver.
B) stomach.
C) kidneys.
D) small intestine.
E) large intestine.

A) liver.

65) Metabolism of amino acids in the citric acid cycle yields
A) more energy than lipid metabolism.
B) more energy than carbohydrate metabolism.
C) approximately the same energy as lipid metabolism.
D) approximately the same energy as carbohydrate metabolism.
E) more energy than lipid and carbohydrate metabolism combined.

D) approximately the same energy as carbohydrate metabolism.

66) A high uric acid level (above 7.4 mg/dl) can lead to the painful condition known as
A) gout.
B) rheumatoid arthritis.
C) anorexia nervosa.
D) lupus.
E) ketosis.

A) gout.

67) Catabolism of protein is not a practical source of quick energy because of all of the following except that
A) proteins are more difficult to break apart than lipids or carbohydrates.
B) the energy yield from protein is less than the yield from lipids.
C) one of the by-products of protein catabolism is ammonia.
D) most individuals have little protein to spare before harming vital organs.
E) extensive catabolism of protein threatens homeostasis.

D) most individuals have little protein to spare before harming vital organs.

68) The removal of amino group from a protein to prepare it to enter the citric acid cycle is termed
A) transamination.
B) deamination.
C) decarboxylation.
D) amination.
E) beta-oxidation.

B) deamination.

69) Protein malnourishment may occur if the diet is deficient in
A) essential amino acids.
B) nonessential amino acids.
C) urea.
D) ammonia.
E) keto acids.

A) essential amino acids.

70) During the absorptive state,
A) the liver forms glycogen.
B) adipocytes release fatty acids to the circulation.
C) skeletal muscle breaks down glycogen.
D) insulin levels are low.
E) skeletal muscle fibers release glucose.

A) the liver forms glycogen.

71) All of the following occur during the postabsorptive state except that
A) glycogenolysis occurs in the liver.
B) levels of blood glucose are elevated above normal.
C) ketone bodies may be formed.
D) fat mobilization occurs.
E) gluconeogenesis occurs in the liver.

B) levels of blood glucose are elevated above normal.

72) During starvation,
A) carbohydrate utilization increases.
B) gluconeogenesis ceases.
C) there is a decline in circulating ketone bodies.
D) muscle proteins are used as an energy source.
E) carbohydrate reserves maintained by metabolizing inorganic compounds.

D) muscle proteins are used as an energy source.

73) When the body is relying on internal energy reserves to continue meeting its energy
demands, it is in the ________ state.
A) postabsorptive
B) absorptive
C) starvation
D) deprivation
E) preabsorptive

A) postabsorptive

74) During the postabsorptive state, ________ stimulate(s) lipid catabolism.
A) glucocorticoids
B) androgens
C) insulin
D) glucagon
E) gastrin

A) glucocorticoids

75) All of the following complement the actions of glucocorticoids in the postabsorptive state except
A) insulin.
B) growth hormone.
C) glucagon.
D) epinephrine.

A) insulin.

76) Compounds that cells can use to make glucose include all of the following, except
A) acetyl-CoA.
B) glycerol.
C) some amino acids.
D) lactate.
E) pyruvate.

A) acetyl-CoA.

77) 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 all of the following, except
A) increased levels of urea in the blood.
B) ketosis and a decreased blood pH.
C) increased gluconeogenesis in the liver.
D) lipid metabolism.
E) glycogenesis.

E) glycogenesis.

78) Following a meal, the absorptive state lasts approximately
A) 30 minutes.
B) 2 hours.
C) 4 hours.
D) 8 hours.
E) 12 hours.

C) 4 hours.

79) Frank has diabetes mellitus and his blood pH has dropped. What is the most likely cause of
his acidosis?
A) a build up of urea
B) excess ammonia production
C) lipoprotein metabolism
D) excess ketone formation
E) increased glycolysis

D) excess ketone formation

80) Nitrogen compounds of the body include all of the following except
A) amino acids.
B) oxaloacetate.
C) creatine.
D) porphyrin.
E) purines.

B) oxaloacetate.

81) The major cation in extracellular fluid is
A) sodium.
B) potassium.
C) calcium.
D) magnesium.
E) iron.

A) sodium.

82) The major cation in cytoplasm is
A) sodium.
B) potassium.
C) calcium.
D) magnesium.
E) iron.

B) potassium.

83) The major anion in body fluids is
A) chloride.
B) bicarbonate.
C) sulfate.
D) iodide.
E) phosphate.

A) chloride.

84) A cation that is essential for muscle contraction, nerve function, and blood clotting is
A) sodium.
B) potassium.
C) calcium.
D) magnesium.
E) selenium.

C) calcium.

85) An ion that is a necessary component of high-energy compounds and nucleic acids and a
structural component of bone is the ________ ion.
A) chloride
B) sulfate
C) phosphate
D) bicarbonate
E) iodide

C) phosphate

86) A cation that often acts as a cofactor for enzymes is
A) sodium.
B) potassium.
C) calcium.
D) magnesium.
E) zinc.

D) magnesium.

87) An element that is a component of hemoglobin, myoglobin, and cytochromes is
A) calcium.
B) magnesium.
C) iron.
D) zinc.
E) cobalt.

C) iron.

88) The element that is necessary for the proper function of the enzyme carbonic anhydrase is
A) iron.
B) cobalt.
C) zinc.
D) selenium.
E) iodine.

C) zinc.

95) The vitamin that is part of the coenzyme FAD is
A) thiamine.
B) riboflavin.
C) niacin.
D) folic acid (folate).
E) cobalamin.

B) riboflavin.

96) The vitamin that is part of the coenzyme NAD is
A) thiamine.
B) riboflavin.
C) niacin.
D) folic acid (folate).
E) cobalamin.

C) niacin.

104) Inorganic ions released through the dissociation of electrolytes are called
A) nutrients.
B) vitamins.
C) trace minerals.
D) free radicals.
E) minerals.

E) minerals.

1) Glycolysis produces how many pyruvate molecules and how many ATP molecules?

A) 1 pyruvate molecule with a net gain of 1 ATP molecule
B) 2 pyruvate molecules with a net gain of 2 ATP molecules
C) 2 pyruvate molecules with a net gain of 4 ATP molecules
D) 4 pyruvate molecules with a net gain of 4 ATP molecules
E) 4 pyruvate molecules with a net gain of 2 ATP molecules

B) 2 pyruvate molecules with a net gain of 2 ATP molecules

2) The energy produced from aerobic metabolism comes from what two sources?
A) glycolysis and the electron transport chain
B) glycolysis and the citric acid cycle
C) citric acid cycle and the electron transport chain
D) glycolysis and fermentation
E) fermentation and the citric acid cycle

C) citric acid cycle and the electron transport chain

3) Where does beta-oxidation take place?
B) in the plasma membrane of cells
C) in the cytoplasm of cells
D) in the mitochondria
E) in the Golgi apparatus

D) in the mitochondria