Physiology Study Guide 3: Cellular Respiration
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Steven A. Fink; Instructor
PHYSIOLOGY STUDY GUIDE 3:
CELLULAR RESPIRATION
True/False
____ 1. Oxidation is a type of catabolic reaction.
____ 2. Proteins are more important as an energy source than carbohydrates.
____ 3. Almost everything we eat is made-up of cells, or was made-up of cells.
____ 4. Most metabolic wastes produced by our body cells are excreted in the feces.
____ 5. As you begin to exercise, the rate of cellular respiration within the muscles
speeds-up.
____ 6. The amount of O2 you consume is proportional to the amount of food that
your body cells oxidize for energy.
____ 7. Diabetes is associated with a person having an abnormally low blood sugar
level.
____ 8. Body heat results from the metabolic reactions occurring in the cells of the
body.
____ 9. In the Electron Transport System, hydrogen atoms are attached to ATP
molecules.
____10. During exercise, the blood sugar level increases.
____11. During cellular respiration, more than ½ of the chemical potential energy
contained in a glucose molecule is released as heat.
____12. The amount of O2 that must be consumed after exercise depends upon the
amount of lactic acid that was formed during exercise.
____13. One molecule of glucose contains more chemical energy than 6 molecules of
CO2.
____14. The hydrogen atoms (& electrons) that are removed from sugars during
cellular respiration, are attached to the oxygen that we inhale.
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____15. "Catabolic hormones" would stimulate the break-down of organic molecules
in body cells for energy.
____16. The amount of CO2 you exhale is proportional to the amount of food that your
body cells oxidize for energy.
____17. Most of the cells of the pancreas are involved in producing insulin.
____18. Carbon dioxide is produced during glycolysis.
____19. Lactic acid is one of the end-products of the Kreb's (Citric Acid) cycle.
____20. Glucose contains more chemical potential energy than two molecules of
pyruvate sugars (pyruvic acid).
____21. The difference in the metabolic reactions occurring in nerve and muscle cells
is primarily the result of differences in the kinds of enzymes produced in
these two cell types.
____22. The mitochondria of a cell produce about twice as much ATP as is
synthesized in the cytoplasm.
____23. The oxygen that we breathe is used within the cell to produce carbon dioxide.
____24. Under anaerobic conditions, fatty acids are broken-down for energy.
____25. Amylase is a digestive enzyme that breaks-down starch.
____26. "Anabolic" steroids stimulate the break-down of organic molecules in body
cells for energy.
Multiple Choice
____27. Substances in our diet such as Vitamin E, Vitamin C, and beta-carotene may
slow the process of aging by:
(a)  the frequency of DNA replication
(b)  the frequency of DNA replication stimulating cell division of nerve
cells
(c) inhibiting the oxidation of organic compounds in our body by "free
radicals”
(d) reducing UV damage of the skin cells
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____28. During exercise, muscle cramps may develop due to the production of:
(a) CO2
(b) citric acid
(c) NAD-H2
(d) ATP
(e) lactic acid
____29. After strenuous exercise an individual continues to breathe at an increased
level because:
(a) this breathing pattern prevents clogging of the airways with mucus
(b) lactic acid must be eliminated via the lungs
(c) accumulated lactic acid must be completely oxidized to CO2 and H2O
using O2
(d) this breathing pattern acts to dissipate heat from the body
(e) of purely psychological factors
____30. The reaction: ADP + Pi + energy  ATP, is called:
(a) phosphorylation
(b) hydrolysis
(c) dehydration synthesis
(d) deamination
(e) transcription
____31. The B-vitamins are primarily associated with:
(a) brain function
(b) hormone synthesis
(c) cellular respiration
(d) digestion
(e) reproduction
____32. The pancreatic islets (Islets of Langerhans) secrete:
(a) oxytocin & glucagon
(b) glucagon & insulin
(c) cortisol & insulin
(d) insulin & adrenalin
____33. All of the following statements about ATP are correct EXCEPT:
(a) ATP is used to provide energy in all cells of the body
(b) ATP releases energy when its chemical bonds are split
(c) ATP is a nucleotide
(d) ATP contains phosphate groups
(e) each ATP molecule contains more energy than each glucose
molecule
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____34. ATP is:
(a) a nutrient that is present in all foods that we eat
(b) produced by the cells in our body by the break-down of food
(c) both (a) and (b) are correct
(d) none of the above
____35. The correct sequence for cellular respiration is:
(a) Kreb’s Cycle  Glycolysis  Electron Transport System 
Transition Reaction
(b) Glycolysis  Electron Transport System  Transition Reaction 
Kreb’s Cycle
(c) Glycolysis  Kreb’s Cycle  Transition Reaction 
Electron Transport System
(d) Glycolysis  Transition Reaction  Kreb’s Cycle 
Electron Transport System
(e) Kreb’s Cycle  Transition Reaction  Glycolysis
Electron Transport System
____36. When O2 is not present, muscle cells break-down ______ glucose molecules
compared to muscle cells with O2 (in order to produce the same amount
of ATP).
(a) fewer
(b) the same number
(c) more
(d) too variable to determine
____37. Most ATP is produced in what series of reactions?
(a) Glycolysis
(b) fermentation
(c) Electron Transport System
(d) Krebs Citric Acid Cycle
(e) deyhydration synthesis
(ab) gluconeogenesis
____38. The Electron Transport System is located in the:
(a) mitochondria
(b) cytoplasm
(c) nucleolus
(d) Golgi Complex
(e) Endoplasmic Reticulum
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____39. The essential difference between combustion of gasoline in a car and the
oxidation of organic molecules in cellular respiration is that:
(a) O2 is not required for combustion of gasoline
(b) no heat is produced in the combustion of gasoline
(c) no CO2 is produced in the combustion of gasoline
(d) the breaking of C-H covalent chemical bonds in cellular respiration is
controlled and step-wise, and not explosive
(e) there are no differences between oxidation of food and combustion of
gasoline
____40. In which series of reactions is glucose converted into 2 molecules of pyruvate
sugars (pyruvic acid)?
(a) Glycolysis
(b) the Krebs (Citric Acid) Cycle
(c) the Electron Transport System
(d) the Transition Reaction
(e) fermentation
(ab) gluconeogenesis
____41. In which series of reactions are acetyl-CoA molecules converted into CO2?
(a) Glycolysis
(b) the Krebs (Citric Acid) Cycle
(c) the Electron Transport System
(d) the Transition Reaction
(e) fermentation
(ab) gluconeogenesis
____42. Most CO2 is formed in what series of reactions?
(a) Glycolysis
(b) fermentation
(c) Electron Transport System
(d) Krebs (Citric Acid) Cycle
(e) Transition Reaction
(ab) gluconeogenesis
____43. Which one of the following series of reactions occurs only when insufficient
O2 is available to the cell?
(a) glycolysis
(b) Krebs (Citric Acid) Cycle
(c) fermentation
(d) Electron Transport System
(e) transition reaction
(ab) gluconeogenesis
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____44. When sugars are broken-apart completely, only about _____% of the energy
released is used to make ATP.
(a) 5
(b) 25
(c) 40
(d) 80
(e) 100
____45. In the Transition Reaction of Cellular Respiration:
(a) pyruvic acid (pyruvate) is broken-down to acetyl-CoA
(b) pyruvic acid (pyruvate) is broken-down to H2O
(c) hydrogen atoms are transferred onto CO2 molecules
(d) pyruvic acid (pyruvate) is converted to lactic acid
(e) hydrogen atoms are transferred onto oxygen atoms
____46. Uric acid is formed from the break-down of:
(a) glycogen
(b) nucleic acids
(c) lactic acid
(d) glucagon
(e) fat
____47. We must breathe O2 in order to survive because oxygen:
(a) is used by the cells of our body to produce sugars & other organic
molecules
(b) is necessary for the formation of ethyl alcohol during fermentation
(c) accepts the hydrogen atoms transferred from hydrocarbon molecules,
as they are broken-down for energy
(d) acts to attach the cells of a multicellular organism together
(e) acts to carry electrical impulses in nerve fibers
____48. Whenever carbohydrates are not available for energy, the body:
(a) can only break-down glucose anaerobically
(b) converts pyruvic acid into lactic acid
(c) breaks-down stored fats forming lactic acid
(d) breaks-down stored fats forming ketoacids
(e) uses B-vitamins for energy
(ab) breaks-down stored starch into CO2 + H20
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alcohol dehydrogenase
C2H4O + NAD-H2  C2H6O + NAD
____49. Which one of the following statements about the above reaction is NOT
correct?
(a) C2H4O is the substrate
(b) H atoms are transferred by NAD
(c) C2H6O is the product
(d) NAD acts as a coenzyme
(e) alcohol dehydrogenase is used-up in the reaction
____50. Ketoacids are formed from the:
(a) deamination of amino acids
(b) incomplete break-down of fatty acids
(c) break-down of glycogen
(d) incomplete break-down of RNA
(e) both (a) and (b)
____51. Which one of the following reactions does NOT occur in the Krebs cycle?
(a) production of reduced coenzymes
(b) production of carbon dioxide
(c) generation of ATP
(d) formation of lactic acid in the absence of oxygen
____52. Weight loss results from an:
(a)  anabolic and  catabolic biochemical reactions
(b)  anabolic and  catabolic biochemical reactions
(c)  anabolic and  catabolic biochemical reactions
(d)  anabolic and  catabolic biochemical reactions
____53. Which series of reactions actually uses oxygen?
(a) Glycolysis
(b) fermentation
(c) Krebs (Citric Acid) Cycle
(d) Electron Transport System
(e) protein synthesis
(ab) gluconeogenesis
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____54. Within a living cell, the oxidation of one molecule is always coupled within the
simultaneous __________ of another molecule.
(a) phosphorylation
(b) hydrolysis
(c) deamination
(d) reduction
(e) oxidation
____55. When fats & proteins are used for energy, they are converted into:
(a) acetyl-CoA
(b) lactic acid
(c) uric acid
(d) prostaglandins
(e) nucleotides
____56. The nitrogen-containing waste product formed from the break-down of
proteins is called:
(a) urea
(b) ketone bodies
(c) nitrogenous bases
(d) pantothenic acid
(e) ascorbic acid
____57. NADH dehydrogenase complex, cytochrome b-c1 complex, and cytochrome
oxidase complex are all:
(a) H-(“proton”) atom pumps embedded in the inner membrane of the
mitochondria
(b) enzymes of the Krebs cycle
(c) enzymes of the Krebs cycle
(d) kinases in the glycolysis reactions
(e) molecules that transport pyruvic acid into the mitocondrion
____58. Diabetes is associated with:
(a) hypoglycemia
(b) hyperglycemia
(c) hypothyroidism
(d) hyperinsulinism
(e) hypokalemia
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Physiology Study Guide 3: Cellular Respiration
____59. Thyroxin hormone:
(a) stimulates the reproductive organs
(b) decreases the blood glucose concentration
(c) stimulates lymphocyte white blood cell production
(d) increases blood calcium concentration
(e) stimulates cellular metabolic rate
____60. Diabetes is associated with a decreased level of:
(a) lactic acid
(b) urea
(c) glucose
(d) insulin
(e) gastrin
____61. Which one of the following does NOT occur in diabetes?
(a) increased catabolism of protein
(b) increased catabolism of fats
(c) hyperglycemia
(d) increased production of ketoacids
(e) increased catabolism of glucose
____62. A cell requires ATP for all of the following processes EXCEPT:
(a) protein synthesis
(b) active transport
(c) cell division
(d) contraction
(e) osmosis
____63. In the Electron Transport System (of Celllar Respiration):
(a) H+ + e- are transferred to oxygen to form water
(b) pyruate sugar (pyruvic acid) is split into acetyl-Coenzyme A
(c) glucose is split into pyruvate sugars (pyruvic acid)
(d) acetyl-Coenzyme A is split into CO2
(e) pyruate sugar (pyruvic acid) is converted into lactic acid
____64. Synthesis of sugars from non-carbohydrates is called:
(a) glycolysis
(b) deamination
(c) glycogenolysis
(d) gluconeogenesis
(e) glycogenesis
(ab) transcription
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____65. "Oxidative Phosphorylation" is associated with:
(a) glycolysis
(b) formation of acetyl-Coenzyme A sugars
(c) the Krebs (Citric Acid) cycle
(d) Electron Transport System
(e) protein synthesis
____66. A person who has elevated ketoacid levels in his bloodstream is probably:
(a) using mostly fats & proteins for energy
(b) producing large amounts of new protein
(c) just starting to exercise
(d) not inhaling enough oxygen
(e) in kidney failure
____67. Glycogen is a(n):
(a) monosaccharide
(b) protein
(c) carbohydrate
(d) hormone
(e) water-soluble coenzyme
____68. Urea is associated with which series of biochemical reactions?
(a) deamination of amino acids
(b) oxidation of glucose
(c) glycogenolysis
(d) fermentation
(e) steroid synthesis
____69. Which one of the following stimulates glycogenolysis in the Liver?
(a) gastrin
(b) bile
(c) pepsin
(d) glucagon
(e) insulin
____70. Our present atmosphere consists mostly of which gas?
(a) oxygen
(b) hydrogen
(c) nitrogen
(d) helium
(e) carbon dioxide
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____71. Which one of the following Olympic class activities increases a person's
endurance?
(a) weight-lifting
(b) shot-put throw
(c) long-jump
(d) pole-vault
(e) 10,000-meter run
____72. The hormone Insulin serves to regulate:
(a) the metabolic rate of the body
(b) the heart rate
(c) the sugar level in the blood
(d) sexual development
(e) red blood cell production
____73. As your blood sugar level increases, ________ is normally released into the
bloodstream.
(a) insulin
(b) thyroxin
(c) gastrin
(d) glycogen
(e) glucagon
____74. After eating a meal, the pancreas secretes _________ Insulin.
(a) less
(b) the same amount of
(c) more
____75. The hormone Glucagon increases:
(a) the splitting of glycogen into glucose  raising blood sugar level
(b) the conversion of glucose into glycogen  lowering blood
sugar level
(c) the digestion of starch into maltose
(d) the digestion of maltose into glucose
(e) the storage of glucose
____76. When O2 is present, muscle cells produce ______ compared to muscle cells
breaking-down the same number of glucose molecules without O2.
(a) less ATP
(b) the same amount of ATP
(c) more ATP
(d) too variable to determine
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____77. The hormone Insulin is produced by the cells of the:
(a) gallbladder
(b) liver
(c) kidney
(d) pituitary gland
(e) pancreas
____78. Which molecule will undergo different biochemical reactions, depending on
whether or not oxygen is available?
(a) acetyl-Coenzyme A
(b) citric acid
(c) glucose
(d) pyruvic acid (pyruvate)
(e) fatty acids
____79. The Glycolysis reactions occur in the _______ of the cell.
(a) cytoplasm
(b) nucleolus
(c) endoplasmic reticulum
(d) mitochondria
(e) Golgi complex
(ab) lysosomes
____80. The total net gain of ATP molecules from the complete oxidation of glucose
is:
(a) 2
(b) 4
(c) 18
(d) 28
(e) 38
(ab) 42
(ac) 46
(ad) 100
____81. The conversion of pyruvate sugar (pyruvic acid) to lactic acid in cells is
called:
(a) gluconeogenesis
(b) fermentation
(c) aerobic respiration
(d) oxidative phosphorylation
(e) glycolysis
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____82. Which one of the following is a catabolic process?
(a) the synthesis (duplication) of DNA
(b) the break-down of glucose for energy
(c) protein synthesis from amino acids
(d) the conversion of fatty acids into triglycerides
(e) the synthesis of glucose into glycogen
____83. The blood vessel that carries nutrient-laden blood from the digestive tract
directly to the Liver is the:
(a) hepatic artery
(b) hepatic vein
(c) hepatic portal vein
(d) bile duct
(e) inferior vena cava
____84. Exhaled air contains ___________ than inhaled air.
(a) less O2, but more CO2
(b) less O2, and less CO2
(c) more O2, and more CO2
(d) more O2, but less CO2
(e) the same amount of O2 and CO2
____85. The molecules entering at the beginning of the Kreb's Cycle are:
(a) lactic acid (lactate)
(b) pyruvate sugars (pyruvic acid)
(c) acetyl-Coenzyme A
(d) ATP
(e) ketoacids (ketone bodies)
(ab) NAD-H2
____86. Amino acids are converted by deamination into:
(a) sugars
(b) ketoacids
(c) fats
(d) uric acid
(e) polypeptides
(ab) steroids
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____87. Lactic acid may be formed as an end-product of:
(a) glycolysis
(b) the Kreb's (Citric Acid) cycle
(c) the Electron Transport System
(d) gluconeogenesis
(e) transcription
____88. Enzymes are chemically:
(a) nucleotides
(b) vitamins
(c) proteins
(d) prostaglandins
(e) steroids
____89. Most hydrogen atoms are carried to the Electron Transport System by:
(a) ATP
(b) NAD
(c) oxygen
(d) Coenzyme-A
(e) calcium
____90. For each glucose molecule broken-down in glycolysis, there is a net gain of
____ ATP produced.
(a) 0
(b) 2
(c) 4
(d) 28
(e) 38
(ab) 50
____91. Glucose is split into 2 pyruvate sugars (pyruvic acid) during:
(a) the Kreb's (Citric Acid) Cycle
(b) the Transition Reaction
(c) glycolysis
(d) oxidative phosphorylation
(e) fermentation
____92. Which one of the following is a catabolic process?
(a) glycogen  glucose
(b) amino acids  protein
(c) nucleotides  nucleic acids
(d) fatty acids  triglycerides
(e) vitamins  minerals
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____93. The names of enzymes usually end with the suffix:
(a) -ide
(b) -ose
(c) -ase
(d) -ine
(e) -one
____94. Oxidation is the:
(a) loss of hydrogens (& electrons) from a molecule
(b) gain of hydrogens (& electrons) to a molecule
(c) loss of an amino group from a molecule
(d) loss of oxygens (& electrons) from a molecule
(e) removal of water from a molecule
____95. The substance that an enzyme changes is called the __________ .
(a) coenzyme
(b) product
(c) substrate
(d) inhibitor
(e) ribosome
____96. Sugars are broken-down into pyruvic acid (pyruvate) in the ________ of a
cell.
(a) lysosomes
(b) mitochondria
(c) cytoplasm
(d) ribosomes
(e) centrioles
____97. Which one of the following is an example of a "catabolic process"?
(a) buffer reaction
(b) condensation reaction
(c) dehydration synthesis reaction
(d) reduction reaction
(e) hydrolysis reaction
____98. Each gram of fat produces about _____ the calories of energy that sugars
do.
(a) the same aount of
(b) 2 times
(c) 4 times
(d) 10 times
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____99. Ketoacids:
(a) are formed as a result of catabolism of monosaccharides
(b) are the result of abnormal protein metabolism
(c) are the result of a decreased rate of fatty acid catabolism
(d) are metabolized by cells throughout the body, but at a limited rate
____100. Substances in our diet such as Vitamin E, Vitamin C, and beta-carotene
may slow the process of aging by:
(a)  the frequency of DNA replication
(b)  the frequency of DNA replication stimulating cell division of nerve
cells
(c) inhibiting the oxidation of organic compounds in our body by "free
radicals”
(d) reducing UV damage of the skin cells
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