Questions:

1. The pH of a solution is 7.4. If half of the hydrogen ions are removed, the new pH would be:
  1. 7.4
  2. 7.2
  3. 7.1
  4. 7.7
  5. 6.4
2. The pKa for ammonium ion is 9.3. At a blood pH of 7.3, there is:
  1. An equal amount of ammonia and ammonium ion
  2. Ten times more ammonia than ammonium ion
  3. One hundred times more ammonia than ammonium ion
  4. Ten times more ammonium ion than there is ammonia
  5. One hundred times more ammonium ion than there is ammonia
3. Phenobarbital is a weak acid with a pKa = 7.1. Its acid form (protonated form) is readily reabsorbed from the kidney filtrate into the blood. Its charged form (salt form) is not reabsorbed from the kidney filtrate into the blood, but rather, finds it way to the urine. Which of the following would you give to an intoxicated patient in order to remove phenobarbital from her system? [Hint! Use the Henderson-Hasselbalch equation for phenobarbital and consider the affect of each of the following.
  1. CO2
  2. Alanine
  3. NH4Cl
  4. NaHCO3
  5. Ascorbic acid
4. Which of the following do you expect to see in a patient with metabolic acidosis with no respiratory compensation?
  1. Decrease of [H+] in blood
  2. Decrease of [HCO3-] in blood
  3. Decrease of [H2CO3] in blood
  4. Decrease of pCO2 in blood
  5. Decrease of dissolved CO2 in blood

5. Refer to the following Figure for Questions 5 and 6. In which row is a structure for lysolecithin found?
  1. Row A
  2. Row B
  3. Row C
  4. Row D
  5. Row E
6. Refer to the following Figure for Questions 5 and 6. In which row is a structure for triacylglycerol found?
  1. Row A
  2. Row B
  3. Row C
  4. Row D
  5. Row E

Figure for Questions 5 and 6

Question 5, In which row is a structure for lysolecithin found?
Question 6, In which row is a structure for triacylglycerol found?
A = Row A, B = Row B, C = Row C, D = Row D, E = Row E
Table of structures for question 5 and 6

7. Refer to the following Figure for Question 7. Which answer is correct
  1. Column A shows Adenine and pyrimidine ring
  2. Column B shows Guanine and pyrimidine ring
  3. Column C shows Thymine and pyrimidine ring
  4. Column D shows Niacin and pyrimidine ring
  5. Column C shows Thymine and purine ring

Figure for Question 7

Table of structures for question 5 and 6

8. Arichidonic Acid is
  1. is depicted as 16:0
  2. is depicted as 18:0
  3. is depicted as 18:Δ9
  4. is depicted as 18:3Δ9,12, 15
  5. is depicted as 20:4Δ5,8,11,14
9. This amino acid has three pKa's and an isoelectric point of 3.1. The amino acid is:
  1. Glutamate
  2. Histidine
  3. Methionine
  4. Cysteine
  5. Cystine
10. Which of the following will migrate the fastest toward the positive end of an electric field?
  1. Alanine at a pH of 11.0
  2. Arginine at a pH of 10.0
  3. Histidine at a pH of 8.0
  4. Tryptophan at a pH of 5.0
  5. Glutamine at a pH of 1.0
11. Which of the following best describes the net charge of the R groups of the following amino acids at the designated pH?
  1. Glutamate: Positively charged at a pH of 7.4
  2. Histidine: Positively charged at a pH of 4.1
  3. Lysine: No charge at a pH of 3.8
  4. Aspartate: Negatively charged at a pH of 1.7
  5. Arginine: Negatively charged at a pH of 6.0

12. What will be the net charge of the protein below at physiologic pH (7.4)?

NH3+-Ala-Phe-Glu-Lys-Arg-Pro-COO-

  1. +2
  2. 0
  3. +1
  4. -1
  5. -2
13. If a polypeptide portion of a protein can assume the same stable conformation that it does in the native protein, it can be called a:
  1. Quaternary structure
  2. Mosaic
  3. Motif
  4. Domain
  5. Native Protein
14. Which of the following characterize the a-helix secondary structure of proteins?
  1. Occur rarely in nature
  2. Involves two antiparallel chains
  3. Includes zinc atoms bound to cysteine and histidine residues
  4. Hydrogen bonds between oxygens and nitrogen atoms four residues apart
  5. Coils rich in proline residues
15. HbA1C is
  1. hemoglobin electrostatically bound to galactose
  2. synthesized only in the kidney, liver, and pancreas
  3. made by the enzyme glucohemoloobin synthase
  4. made during protein synthesis
  5. a measure of blood glucose during the past 6 weeks
16. As you read about, Michel Sichel just experienced a sickle cell crisis. Which of the following statements about sickle cell anemia is TRUE?
  1. Aspartate is substituted for cysteine on HbS subunits
  2. Red blood cells are usually only "sickle" shaped in tissue capillaries
  3. The "anemia" is from an iron deficiency
  4. Amino acid substitution results in a hydrophobic knob or area
  5. "Pain" associated with this disease is from vessel wall injury
17. When lactate is oxidized to pyruvate:
  1. Two electrons and two protons are transferred to NAD+
  2. Two electrons and two protons are transferred from NAD+
  3. One electron and two protons are transferred to NAD+
  4. One electron and two protons are transferred from NAD+
  5. Two electrons and one protons are transferred to NAD+

18. The drug allopurinol is used to treat gout. Which of the following common biological pathways is inhibited by the drug?
  1. The conversion of urate to hypoxanthine
  2. The conversion of urate to xanthine
  3. The conversion of hypoxanthine to inosine monophosphate
  4. The conversion of guanine to guanosine monophosphate
  5. The conversion of GMP to urate
19. To stabilize the transition state complex, which of the following must be lowered?
  1. Initial energy state
  2. Activation energy
  3. Net energy change
  4. The Vmax
  5. Final energy state
20. The following enzyme reaction is an example of a(n)?
Glucose + ATP = Glucose-6-phosphate + ADP
  1. Oxidoreductase
  2. Transferase
  3. Hydrolase
  4. Lyase
  5. Ligase
21. During muscle contraction, calcium is released from the endoplasmic reticulum. An increase in glycogenolysis is initiated when calcium binds to
  1. Calmodulin
  2. Troponin I 
  3. Protein kinase A
  4. Zymogen
  5. Protein phosphatase
22. If an enzyme is described by the Michaelis-Menten equation, a competitive inhibitor will:
  1. decrease the Km and decrease the Vmax
  2. decrease the Km, but not the Vmax
  3. always just change the Vmax
  4. increase the Km but not change the Vmax
  5. increase the Km and decrease the Vmax
23. You have isolated the control enzyme phosphofructokinase-1. When you plot the initial velocity vs. substrate concentration, an S-shaped curve results. This reflects
  1. competitive inhibition
  2. that an allosteric activator is absent
  3. that the enzyme is phosphorylated
  4. Michaelis-Menten kinetics
  5. cooperative binding

24. An apoenzyme
  1. Includes non-protein compounds such as metal ions
  2. Consists of complex organic structures which may be classified as activation-transfer coenzymes or oxidation-reduction coenzymes
  3. Is the protein portion of the enzyme without the cofactors
  4. Includes vitamins E and C
  5. None of the above
25. As a result of insulin binding to the insulin receptor, the GRB protein binds to the IRS. The binding of the GRB adaptor protein occurs because the IRS contains
  1. A phosphorylated tyrosyl residue
  2. A phosphorylated seryl residue
  3. A src homology binding domain (SH2 domain)
  4. Bound inositol trisphosphate
  5. An alpha-1 receptor
26. When epinephrine binds to alpha-1 receptors, one result is
  1. The receptor binds to the IRS-protein
  2. The receptor inhibits phospholipase-C
  3. The endoplasmic reticulum releases calcium ions
  4. There is a reduction in the diacylglycerol concentration
  5. Calmodulin dissociates from all the proteins to which it normally binds
27. Concerning Mya Sthenia who has myasthenia gravis, her chemical messenger system differs from a normal person because she has too
  1. little calcium released near the presynaptic membrane
  2. many inhibitory proteins in the neuromuscular junction
  3. much vesical fusion in the presynaptic junction
  4. much acetylcholine esterase
  5. few acetylcholine receptors in the postsynaptic membrane
28. When epinephrine binds to a b-receptor on the liver membrane and activates a Gαs signal transduction protein,
  1. The Gαs protein releases GTP and binds to GDP
  2. The Gαs protein dissociates into an αβ- complex and a γ-subunit
  3. The enzyme adenylyl cyclase is inhibited
  4. Cyclic-AMP and PPi are produced
  5. Protein kinase A is inhibited by cyclic-AMP
29. Given the following reactions:

A + H20 = B + C   Delta-Go' = + 11 kcal/mol
D + H20 = B + G   Delta-Go' = + 3 kcal/mol
K + H20 = B + L   Delta-Go' = -7 kcal/mol
J + H20 = B + M   Delta-Go' = -5 kcal/mol

Which of these reactions would be exergonic when proceeding from left to right?

  1. A + G = C + D
  2. A + M = C + J
  3. D + M = G + J
  4. A + L = K + C
  5. K + M = J + L

30. NAD+, FAD, and FMN are all cofactors for:
  1. Oxidoreductases
  2. Transferases
  3. Hydrolases
  4. Lyases
  5. Ligases
31. All of the following would help to explain why ischemia would cause a failure of the left ventricular muscle to eject a normal amount of blood EXCEPT:
  1. Without oxygen, the electron transport system is inhibited
  2. Without oxygen, a proton gradient could not be maintained
  3. Without oxygen, an adequate amount of oxidative phosphorylation can not occur
  4. Without oxygen, there will not be enough ATP to cause adequate muscle contraction
  5. Without oxygen, intracellular calcium concentrations cannot be maintained at a high enough level
32. For the reaction A = B + C, the concentration of A is 1 mM, the concentration of B is 1 mM and the concentration of C is 2 mM. Also, standard free energy change for the reaction under biological conditions is Delta-Go' = 0 kcal/mole and free energy change for the reaction is Delta-G = - 3.7 kcal/mole. If the concentration of C is lowered to 1 mM,
  1. The reaction will be at equilibrium
  2. The reaction will proceed from right to left
  3. The Delta Go' will become more negative
  4. The Delta G will become more negative
  5. The Delta Go' will become more positive
33. When muscles contract, a chain of events result in greater activity by the TCA cycle. All of the following are links in that chain EXCEPT:
  1. The ADP concentration increases
  2. The proton gradient across the mitochondrial membrane is diminished
  3. The electron transport chain produces more water
  4. The concentration of NADH decreases and the concentration of NAD+ increases
  5. Alpha-ketoglutarate dehydrogenase is inhibited by phosphorylation
34. The TCA cycle:
  1. Is found in the cytosol
  2. Is controlled by calcium ion, the ADP/ATP ratio, and the NADH concentration
  3. Is also called the Cori cycle
  4. Consumes most of the CO2 produced by ribosomes
  5. Produces most of the water made in humans
35. Which of the following statements regarding the four "dehydrogenases" of the TCA cycle is INCORRECT?
  1. These are enzymes which remove electrons in the form of hydrogen from various structures and transfer them to others
  2. At least one catalyzes the "rate-limiting steps" of the TCA cycle
  3. GTP is generated from one of them via substrate level phosphorylation
  4. NAD+ and FAD are the electron-accepting coenzymes for these enzymes
  5. At least one catalyzes a reversible reactions

36. The rate at which pyruvate from glycolysis is used by the TCA cycle to produce energy is regulated by pyruvate dehydrogenase. During muscle contraction, this enzyme is
  1. Inhibited by increases in the calcium concentration.
  2. Activated by increased in acetyl CoA
  3. Activated by increases in NADH
  4. Activated by increases in ADP
  5. Inhibited by increases in AMP
37. If a muscle begins to work hard, the ATP concentration of the cell will drop. In turn, the pyruvate dehydrogenase reaction will be activated. Which of the following mechanisms will NOT play a role, either directly or indirectly, in this activation?
  1. Increased Ca++ will cause dephosphorylation and activation of the enzyme
  2. Increased ADP will inhibit phosphorylation of the enzyme and activate the enzyme
  3. Increased ADP will activate ATP synthase and lower the proton gradient
  4. A lower proton gradient will increase the utilization of NADH
  5. Increased NADH will activate pyruvate dehydrogenase
38. The chemiosmotic theory holds all of the following EXCEPT:
  1. The inner mitochondrial membrane is impermeable to protons
  2. The cytosol has a higher pH than the matrix
  3. In the absence of a proton motive force, ATP will not be synthesized
  4. The electrochemical potential comes from both the electrical potential and the proton concentration gradient
  5. Electrons are passed from one carrier to the next as protons are pumped across the inner mitochondrial membrane
39. When the electron transport chain is exposed to cyanide,
  1. It becomes uncoupled
  2. More ATP is made
  3. The concentration of NADH increases
  4. The cytochromes are all oxidized
  5. The pumping of protons increases resulting in an increase in the proton gradient.
40. Which of the following can increase the permeability of membranes to protons and thus decrease ATP synthesis while increasing the consumption of O2
  1. An inhibitor of cyt a + a3
  2. An inhibitor of complex I
  3. An inhibitor of complex II
  4. An inhibitor of complex III
  5. A proton ionophore
41. During aerobic glycolysis, the conversion of glucose to pyruvate, what is the net production of energy in ATP equivalents?
  1. 3 ATPs
  2. 4 ATPs
  3. 5 ATPs
  4. 7 ATPs
  5. 10 ATPs

42. You have a patient who eats hard candy throughout the day. The patient also has dental caries. Which of the following is part of the correlation between eating candy and dental caries?
  1. Glucose from the sucrose is catabolized aerobically by bacteria
  2. Aerobic metabolism of glucose produces hydroxyapatite like crystals which are imperfect
  3. Anaerobic metabolism produces pyruvate which is basic and attacks hydroxyapatite
  4. Aerobic metabolism produces pyruvate which raises the pH about 9.0. This pH dissolves teeth
  5. Anaerobic metabolism produces lactate and lowers the pH below 5.0. Acid dissolves bone
43. When undergoing strenuous exercise the Cori Cycle is functioning. Which of the following compounds is being delivered to muscle tissue as part of this Cycle?
  1. Glucose
  2. Lactate
  3. Galactose
  4. Pyruvate
  5. Alanine
44. Anemia, hemorrhage, and chronic obstructive pulmonary disease can all cause metabolic acidosis. The best explanation is that the lack of oxygen causes
  1. a decrease in insulin that, in turn, increases anaerobic glycolysis in the brain
  2. a decrease in oxidative phosphorylation so the cells have to rely upon anaerobic glycolysis
  3. a decrease in the oxidation of tyrosine to epinephrine which decreases gluconeogenesis in muscle
  4. a decrease in the removal of CO2 from the blood. The resulting decrease in pH causes an increase in glycolysis in most cells
  5. an increase in glycolysis in red blood cells
45. All of the following are substrates or products of the fatty acyl CoA synthetase reaction EXCEPT:
  1. PPi
  2. Acyl CoA
  3. ATP
  4. CoA
  5. ADP
46. In the fasting state, more ketone bodies are made in the liver because:
  1. Free fatty acid synthesis is increased
  2. Malonyl CoA inhibits carnitine palmitoyl transferase I
  3. The concentration of blood albumin increases
  4. More fatty acid transporters appear on the surface of liver cells
  5. More triacylglycerol is hydrolyzed in adipose cells
47. Free fatty acids are able to travel from adipose tissue to muscle or liver
  1. As independent water soluble compounds in the blood
  2. By using receptors on red blood cells
  3. Bound to serum proteins
  4. Free fatty acids do not travel to liver
  5. By using enzymes that modify them

48. Which of the following is NOT TRUE following β-oxidation in the liver?
  1. The formation of propionyl CoA could lead to the production of glucose from B-oxidation
  2. The formation of acetyl CoA could lead to ketone bodies synthesis
  3. Acetyl CoA could be converted to pyruvate allowing for the production of glucose
  4. Acetyl CoA could be used for the synthesis of HMG CoA
  5. Acetyl CoA might be oxidized by the TCA cycle
49. All other things being constant, an increase in glucagon would result in an increase in
  1. Fatty acid synthesis in adipose tissue
  2. β-oxidation in liver
  3. Malonyl CoA concentrations in liver
  4. Protein synthesis in muscle
  5. Glycogenolysis in muscle
50. Your patient has an insulinoma. 6 hours after a meal, her blood:
  1. Glucagon would be increased
  2. Free fatty acid concentration would be normal
  3. C-peptide concentration would be increased
  4. Epinephrine concentration would be normal
  5. Concentration of glucose would be normal
51. Concerning Anne Sullivan who has suffered from NIDDM for five years. Which of the following statements is true?
  1. Her blood insulin will not be in the normal range
  2. Her β-cells are secreting enough insulin
  3. Her muscle cells are responding normally to insulin
  4. Her adipose cells are responding normally to insulin
  5. Her rate of gluconeogenesis is abnormal
52. Insulin is secreted by the B-cells of the pancreas into the hepatic portal vein. Which of the following regarding insulin synthesis is FALSE:
  1. The active form of insulin is composed of two polypeptide chains linked by two interchain disulfide bonds
  2. The A-Chain has an intrachain disulfide bond
  3. Insulin is synthesized as a preprohormone which is converted to proinsulin
  4. Stimulation of A-cells by glucose causes exocytosis of the insulin storage vesicles
  5. Cleavage of proinsulin to insulin yields a C-peptide
53. A woman body builder passed out and went into a coma while lifting weights. When she arrived at the emergency room, her blood glucose was 24 mg/dL (normal - 70 - 105 mg/dL). Her friend said that she had injected 60 units of regular (short acting) insulin before each meal for the last 5 meals. This is at least 4 times normal basal secreting of insulin. Insulin had all of the following effects EXCEPT:
  1. Increased glucose transport into muscle
  2. Decreased glycogen phosphorylase activity in muscle
  3. Decreased gluconeogenesis in liver
  4. Increased glucose uptake into brain
  5. Decreased glycogen phosphorylase in liver

54. In liver and muscle, glycogen synthesis is characterized by all of the following EXCEPT:
  1. The phosphorylation of glucose
  2. The formation of UDP-glucose
  3. The actions of the enzyme glycogen synthase, activated by the hormone glucagon
  4. The actions of a branching enzyme, to ensure branching
  5. The conversion of glucose-6-phosphate to glucose-1-phosphate by the enzyme phosphoglucomutase
55. Which of the following statements is CORRECT regarding the function of glycogen in liver and skeletal muscle?
  1. In both skeletal muscle and liver, the glucose-6-phosphate formed enters the glycolytic pathway
  2. Glycogen is an important fuel source for skeletal muscle when ATP demands are low
  3. Glycogen in skeletal muscle is produced by gluconeogenesis during a prolonged fast
  4. Liver glycogen is the first and immediate source of glucose for the maintenance of blood glucose levels
  5. The pathways of glycogenolysis and gluconeogenesis in a liver cell are not activated together
56. What is the effect of increases in protein kinase A activity upon the activity of glycogen synthase and glycogen phosphorylase?
  1. Dephosphorylation and inactivation of glycogen phosphorylase
  2. Phosphorylation and activation of glycogen synthase
  3. Dephosphorylation and activation of glycogen synthase
  4. Phosphorylation and activation of glycogen phosphorylase
  5. Phosphorylation and inactivation of glycogen phosphorylase
57. The activity of the oxidative portion of the pentose phosphate pathway is controlled by the:
  1. Cytosolic concentration of ribose-1-phosphate
  2. Mitochondrial concentration of ribose-5-phosphate
  3. Concentration of glyceraldehyde-3-phosphate
  4. Concentration of NADPH in the cytosol
  5. Concentration of NAD+ in the endoplasmic reticulum
58. NADPH is used for
  1. Oxidizing vitamin C
  2. Oxidizing vitamin E
  3. Oxidizing glutathione
  4. Reductive biosynthesis of fatty acids
  5. β-oxidation of fatty acids
59. During the Korean War, 10 percent of black servicemen given the drug primaquine developed drug-induced hemolytic anemia. These men had only 15 percent of the normal somatic activity of
  1. Glutathione reductase
  2. Phosphoglucoisomerase
  3. Glucose-6-phosphate dehydrogenase
  4. 6-phosphogluconate dehydrogenase
  5. Gluconolactonase
60. All of the following enzymes and metabolites are found in the pathway for the reduction of HOOH except
  1. 6-phosphogluconate dehydrogenase
  2. NADH + H+
  3. Glutathione reductase
  4. Reduced glutathione
  5. Glutathione peroxidase

61. Liver cells are able to release glucose to the circulation from both glycogen and gluconeogenesis. Which of the following enzymes is important to both of these processes?
  1. hexokinase
  2. fructose-2, 6-bisphosphatase
  3. glucokinase
  4. glucose-6-phosphatase
  5. fructose-1, 6-bisphosphatase
62. After strenuous muscle activity, lactate produced from anaerobic glycolysis is recycled in the liver by being ____________________ in a reaction catalyzed by lactate dehydrogenase.
  1. oxidized by NADH to form oxaloacetate
  2. reduced by NADH to form oxaloacetate
  3. oxidized by NAD+ to form pyruvate
  4. reduced by NAD+ to form pyruvate
63. A person eats a meal and then watches TV or sleeps for the next 16 hours of a fast. At 16 hours, what is the source of their blood glucose?
  1. 100% from gut
  2. 100% from gluconeogenesis
  3. 100% from glycogenolysis
  4. 50% from gut and 50% from gluconeogenesis
  5. 50% from glycogenolysis and 50% from gluconeogenesis
64. Which of the following occurs during prolonged fasting (starvation)?
  1. Tissues use the same amount of glucose that they use during a brief fast
  2. Blood glucose levels decrease drastically during a four-week fast
  3. As a fast progresses, tissues rely predominantly on fuels derived from adipose triacylglycerols
  4. Blood ketone levels decrease dramatically after 3-5 days of fasting
  5. After 3-5 days of fasting, the brain increases its utilization of glucose and the rate of gluconeogenesis and the production of urea increases
65. Which of the following is an essential fatty acid?
  1. linoleic
  2. palmitic
  3. oleic
  4. stearic
  5. palmitoleic
66. S-adenosylmethionine is important in the synthesis of
  1. Ethanolamine from diacylglycerol
  2. Phosphatidylcholine from diacylglycerol and CDP-choline
  3. Phosphatidylcholine from phosphatidylethanolamine
  4. Phosphatidylethanolamine from phosphatidylserine
  5. Phosphatidylserine from phosphatidylethanolamine
67. Palmitoyl CoA and other activated long chain fatty acids can be elongated two carbons at a time by a series of reactions that occur in the:
  1. Endoplasmic reticulum
  2. Golgi complex
  3. Lysosome
  4. Cytosol
  5. None of the above

68. An infant is born prematurely and has respiratory distress syndrome. All of the following will be low EXCEPT
  1. Dipalmitoylphosphatidylcholine
  2. Phosphatidyl glycerol
  3. Surface active proteins
  4. Lung surfactant
  5. Sphingomyelin
69. The pathway for the synthesis of glycogen from portal blood glucose in the liver:
  1. Uses activated hexokinase
  2. Is inhibited by glucose
  3. Is inhibited by insulin
  4. Uses activated glycogen phosphorylase
  5. Is inhibited by high cAMP
70. A patient with type I diabetes has come to the emergency room with ketoacidosis. All of her serum samples are opalescent, ie, they scatter light. Compared to a normal person, all of the following probably contributed to this abnormal serum EXCEPT:
  1. Capillaries don't have as much lipoprotein lipase activity
  2. Adipose hormone sensitive lipase is more active
  3. More VLDL is being synthesized in the liver
  4. The cyclic-AMP concentration of adipose tissue is high
  5. Brain usage of free fatty acids is down
71. Your patient sufferers from type I diabetes. Compared to a normal person your patient will have
  1. Less serum lipoproteins
  2. Lower blood glucose
  3. Decreased production of lipoprotein by the liver
  4. Decreased lipoprotein lipase activity
  5. Decreased hormones sensitive lipase activity
72. The following are all effects of insulin EXCEPT
  1. Stimulation of acetyl CoA carboxylase
  2. Stimulation of the lipolytic activity of hormone sensitive lipase (HSL)
  3. Stimulates adipose cells to synthesize and secrete LPL (lipoprotein lipase)
  4. Stimulates the enzyme glucose-6-phosphate dehydrogenase
  5. Increase in the number of glucose transporters in adipose cell membranes
73.What is the name of the cofactor for AST, ALT, or any other transamination reaction?
  1. NAD+
  2. Acetyl CoA
  3. Pyridoxal phosphate (PLP)
  4. FADH2
  5. NADPH
74. Your patient has hepatitis A which has developed into hepatic encephalopathy. All of the following might be helpful EXCEPT:
  1. Low protein diet
  2. Antibiotics
  3. Lactulose
  4. Enemas
  5. Low carbohydrate diet

75. Which of the following reactions takes place in the mitochondria during the synthesis of urea from ammonium ion and glutamate?
  1. Argininosuccinate lyase
  2. Argininosuccinate synthetase
  3. Ornithine transcarbamoylase
  4. Arginase
76. Alanine aminotransferase (ALT) transfers an amino group from alanine to
  1. Pyruvate
  2. alpha-ketoglutarate
  3. Oxaloacetate
  4. Methionine
  5. Carbamoyl phosphate
77. Which of the following is an essential amino acid?
  1. Glutamine
  2. Proline
  3. Methionine
  4. Cysteine
  5. Asparagine
78. You suspect that your 12 year old male patient has an inborn error in methionine metabolism. His methionine levels are low and his homocysteine levels are high. A liver biopsy indicates that his cystathionine synthase and cystathionase levels are normal. This patient may have a deficiency:
  1. Of vitamin B12
  2. Of folic acid
  3. A deficiency in the pathway that synthesizes methyl cobalamin
  4. A deficiency in the pathway that synthesizes N5-methyl tetrahydrofolate
  5. All of the above
79. The catabolic products of isoleucine, methionine, and valine all enter into the TCA cycle or glycolysis as
  1. Pyruvate
  2. Oxaloacetate
  3. Succinyl CoA
  4. Acetyl CoA
  5. Fumarate
80. The patient-has normal cystathionine levels and normal vitamin B12 metabolism. She has an inborn error in the pathway for tetrahydrofolate production. Which of the following would be at a lower concentration when compared to a healthy individual?
  1. Methionine
  2. Serine
  3. Cystathionine
  4. Homocystine
  5. Cystine

81. Ketoacidosis refers to the metabolic acidosis caused by the overproduction of ketoacids. The classic form of ketoacidosis is uncontrolled diabetes mellitus. All of the following would occur in a patient suffering from a diabetes-induced metabolic acidosis (diabetic ketoacidosis) EXCEPT:
  1. Deep and/or rapid breathing causes a decrease in the partial pressure of carbon dioxide (PaCO2) in the blood.
  2. The removal of carbon dioxide through deep, rapid breathing results in a rise in the blood pH
  3. When endogenous acid production rises sharply, net acid excretion cannot keep pace and the bicarbonate lost in buffering is not replaced causing plasma HCO3- levels to fall
  4. Serum bicarbonate levels will decrease after the administration of an insulin injection
  5. The fall in insulin causes fat cells to liberate fatty acids, which flood the hepatocytes
82. Sickle cell disease results from a point (missense) mutation of the b-globin of:
  1. Glutamine for valine
  2. Valine for glutamate
  3. Hydrophobic amino acid for another hydrophobic amino acid
  4. Hydrophilic amino acid for another hydrophilic amino acid
  5. Hydrophilic amino acid for a hydrophobic amino acid
83. Aldolase is classified as a(n)
  1. Oxidoreductase
  2. Transferase
  3. Hydrolase
  4. Lyase
  5. Isomerase
84. When the blood concentration of insulin is increased, less glucagon is produced and there is an increase in
  1. the activity of adenylate cyclase
  2. the activity of cAMP phosphodiesterase (3’, 5’-phosphodiesterase)
  3. binding of cAMP to the inhibitory subunits of protein kinase A
  4. cAMP
  5. protein kinase A activity
85. The ΔG and ΔG0! Both refer to the free energy change in a steady state reaction.  Steady state means that the concentrations of substrates and products are fixed or constant.  All of the following statements about ΔG and ΔG0! Are true EXCEPT
  1. ΔG refers to a specific reaction with fixed (constant) concentrations of substrate and products
  2. ΔG0! refers to a reaction at pH = 7 and 25 degrees centigrade
  3. ΔG0! refers to a reaction with the concentrations of substrates and products, except hydrogen ion, fixed at one molar concentrations
  4. ΔG and ΔG0! can both have positive or negative values
  5. ΔG0! for a specific reactions can have many values
86. Your patient is an alcoholic with a buildup of a-ketoacids and symptoms of wet beriberi. All of the following might be part of a scenario that would explain why peripheral vessels dilate and cardiac muscles loose their contractility EXCEPT
  1. Muscle needs ATP to contract
  2. Most ATP is produced by oxidative phosphorylation
  3. NADH and FADH2 are produced by the TCA cycle
  4. The TCA cycle needs thiamine pyrophosphate to function
  5. A shortage of thiamine results in the inability to oxidize NADH

87. In the muscle, all of the following are part of the pathway whereby increased epinephrine causes an increase in the glycolytic pathway EXCEPT
  1. Increased binding of GTP to G-protein
  2. Activation of the cAMP cascade
  3. Increased phosphorylation of enzymes by protein kinase A
  4. Activation of fructose-2,6-bisphosphatase and inhibition of phosphofructokinase-2
  5. Increased binding of fructose-2,6-bisphosphate to phosphofructokinase-1
88. All of the following help to explain the mechanism for releasing insulin from β-cells in response to the concentration of blood glucose - EXCEPT
  1. The important regulator of glycolysis in β cells is the concentration of glucose reacting with glucokinase
  2. ATP is made in proportion to the rate of glycolysis
  3. The rate of K+ leaving the cell through a potassium channel is a major determinant of the polarization of the cell membrane
  4. ATP inhibits the K+-channel, the more ATP, the less K+ leaving the cell, and the less polarized (more depolarized) the cell membrane
  5. Depolarization causes Ca++ to exit the cell and insulin leaves the cell through the insulin transporter
89. All of the following statements about the pentose phosphate pathway are true EXCEPT

  1. Its two functions are to produce NADPH and ribose-5-P
  2. It uses glucose-6-P as a substrate when producing NADPH and CO2
  3. Glucose-6-phosphate dehydrogenase is the control enzyme and it is regulated by the NADPH concentration of the cell
  4. If it is producing more than twice as much NADPH as ribose-5-P, it can produce glyceraldehyde-3-P and fructose-6-P
  5. It is found in the mitochondria of liver, muscle and brain but is absent from most other tissues of the body.
90. The most important control step in gluconeogenesis is fructose-1,6-bisphosphatase.  All of the following statements are true EXCEPT

  1. Fructose-1,6-bisphosphatase converts fructose-2,6-bisphosphate to fructose-6-phosphate
  2. During times when insulin is high, fructose-1,6-bisphosphatase is inhibited by fructose-2,6-bisphosphate
  3. During a fast or exercise when glucagon and/or epinephrine are high, fructose-1,6-bisphosphatase is active because of the absence of fructose-2,6-bisphosphate
  4. Glycolysis or gluconeogenesis cannot be active at the same time.  If they were is would be a futile cycle
  5. In the liver, fructose-2,6-bisphosphate is made by the enzyme phosphofructokinase-2.  This enzyme is inhibited by the cAMP cascade
91. When the concentration of epinephrine or glucagon is high, they bind to receptors on adipose cell membrane and all of the following can be expected to occur EXCEPT

  1. The cAMP cascade activates hormone sensitive lipase
  2. Triacylglycerol is hydrolyzed to free fatty acids and glycerol
  3. Free fatty acids are carried to most tissues of the body by albumin
  4. Fatty acids are activated, enter the mitochondria, and are oxidized by β-oxidation and the TCA cycle
  5. Increased β-oxidation increases glycolysis in resting muscle

92.This patient has a deficiency of argininosuccinate lyase and has very high concentrations of blood glutamine and ammonium ion.  You could treat her with all of the following EXCEPT
  1. Low protein diet
  2. Arginine supplementation to her diet
  3. Oral doses of hippuric acid and phenylacetylglutamine
  4. Benzoic acid tablets
  5. Oral doses of pheylbutyrate
93. Your patient has a high serum homocysteine level and a defect in the enzyme that transfers one-carbon units from N5-methyltetrahydrofolate to form methylcobalamin (B12). The greatest change from normal would be in the rate of conversion of
  1. Methionine to homocysteine
  2. Homocysteine to methionine
  3. Homocysteine to succinyl CoA
  4. Serine to cysteine
  5. Cysteine to pyruvate and H2SO4

Answers:

As a reference point, previous classes scored a combined mean of 68% for questions 1 through 93. The mean score is in the middle of the B range. Please note that questions 81 to 93 were Practice Questions.
1. Answer: D, 76%, Chapter 4, Objective 3; “Define pH. Given any hydrogen ion concentration, determine the pH and visa versa.”
2. Answer: E, 86%, Chapter 4, Objective 12; “Draw the dissociation of ammonium ion. If the pKa =9.3, what form is found at pH =7?”
3. Answer: D, 80%, Chapter 4, Objectives 7 and 12; “Given a weak acid, be able to draw the equation for its dissociation and label the conjugate base (salt of the acid). Be able to define the Ka for the acid. Be able to write the Henderson-Hasselbalch equation for acid. Draw the dissociation of ammonium ion. If the pKa =9.3, what form is found at pH=7?
4. Answer: B, 60%. Chapter 4, Objective 14; “Regarding the Di Beatty Case; Explain why an increase in a metabolic acid would cause the changes seen in PaCO2 and serum bicarbonate. What would happen to the concentration of CO2 and serum bicarbonate after the insulin injection?
5. Answer: D, 44%. Chapter 5, Objective 16; “What does the lyso in lysolecithin indicate?
6. Answer: A, 67%, Chapter 5, Objectives 14, "Recognize a mono, di and triacylglycerol."
7. Answer: C, 76%, Chapters 5, Objectives 21; “Be able to recognize the structure of a purine and a pyrimidine base. Be able to identify the structure of adenine, guanine or thymine.
8. Answer: E, 76%, Chapters 5, Objectives 11; “Be able to identify the structure of a fatty acid. Be able to differentiate between Palmitic acid, Stearic acid, Oleic acid, a-Linolenic acid and Arachidonic acid.
9. Answer: A, 69%. Chapter 6, Objective 13; “ Given any amino acid except cysteine serine, threonine and tyrosine, be able to predict the isoelectric point!”
10. Answer: A, 31%, Chapters 6, Objectives 1 and 10; “What is the approximate pKa for all alpha-amino groups and for all alpha-carboxyl groups? Are they charged at pH=7? Given the pH, predict whether the amino acids aspartic acid, glutamic acid histidine, lysine, and arginine would be neutral or would carry a net negative or net positive charge.
11. Answer: B, 70% Chapter 6, Objective 10; ”Given the pH, predict whether the R-groups of the amino acids aspartic acid, glutamic acid, histidine, lysine, and arginine would be neutral or would carry a net negative or net positive charge.
12. Answer: C, 54%. Chapter 6, Objective 10; “Given the pH, predict whether the amino acids aspartic acid, glutamic acid, histidine, lysine, and arginine would be neutral or would carry a net negative or net positive charge.”
13. Answer: D, 72%. Chapter 7, Objective 7; “What is a structural domain?

14. Answer: D, 64%, Chapter 7, Objective 2 “Be able to recognize and discern between the three types of secondary structure discussed in class!”
15. Answer: E, 43%, Chapter 7, Objective 27; “Concerning Di Abietes, What is HbA1c? How is it made and what does it measure?”
16. Answer: D, 81%, Chapter 7, Objective 24 “Concerning Will Sichel: In biochemical terms, explain the development of pain during a sickle cell crises. Include the specific mutation, oxygen pressure, and protein conformation in your answer.”
17. Answer: E, 47%. Chapter 8, Objective 12; “Concerning NAD+, what vitamin is it synthesized from? When lactate dehydrogenase or alcohol dehydrogenase oxidize their substrates, what is transferred to NAD+? Besides pyruvate and acetaldehyde, what is the other reaction product? What is the function of the ADP portion of NAD+?”
18. Answer: E, 18%. Chapter 8, Objective 18; “Explain why allopurinol is used to treat gout. Is allopurinol a irreversible inhibitor? Is allopurinol a suicide inhibitor? Why?
19. Answer: B, 81%, Chapter 8, Objective 5; “Define catalytic power. Explain catalytic power in terms of the transition state and activation energy.”
20. Answer: B, 73%. Chapter 8, Objective 21; “Be able to name the 6 major classes of enzymes. Given one of the following reactions, be able to match it with one of the 6 major classes of enzyme reactions catalyzed: alcohol dehydrogenase, glucokinase, chymotrypsin, aldolases, triosephosphate isomerase, and pyruvate carboxylase.
21. Answer: A, 83%. Chapter 9, Objective 16; “Explain how an increase in calcium in muscle cells simultaneously activates muscle contraction and glycogenolysis. Which system uses ATP and which helps to produce ATP?
22. Answer:D, 70%, Chapter 9; Objective 4, “ What is the effect of a competitive inhibitor on the KM and Vmax?
23. Answer: E, 35%. Chapter 9, Objectives 8 ;”The substrates of allosteric enzymes exhibit positive cooperativity. Explain positive cooperativity in terms of conformation and activity of the active site.”
24. Answer: C, 79%, Chapter 7, Objective 16; “What is a ligand? What is an apoprotein? What is a holoprotein? What would an apoenzyme be?”
25. Answer: A, 50%, Chapter 11, Objectives 9 and 10, “ When a protein contains a src homology 2 domain (SH2 domain), what does it bind to? Is the binding specific? “ “ In the Ras and MAP kinase pathway, how does the occupied receptor activate Grb2? What is the last step in the pathway that is catalyzed by MAP-kinase and what is the effect?”
26. Answer: C, 62%, Chapter 11, Objectives 11 and 25, “ What are the functions served by phosphatidylinositol phosphates in signal transduction? “ “ When phosphatidyl inositol bisphosphate is hydrolyzed by phospholipase C, what is the next step in the signal transduction pathway for diacylglycerol? What are the next several steps in the signal transduction pathway for inositol trisphosphate? Use protein kinase C, target proteins, endoplasmic reticulum, calcium, calmodulin, and calmodulin binding proteins in your answer.”
27. Answer: E, 70%, Chapter 11, Objectives 3 and 27, “ Beginning with the response to a stimulus, list the common characteristics of all chemical messenger systems as they apply to the chemical messenger acetylcholine at the neuromuscular junction. Use the terms nerve cell action potential, Ca2+-channel, vesicles, fusion, presynaptic membrane, acetylcholine, diffusion, acetylcholine receptors, gated ion channels, muscle cell action potential, and acetylcholinesterase.” “ Concerning Mya Sthenia who has myasthenia gravis, explain how her chemical messenger system differs from a normal person. How did this happen? Why do the anticholinesterase drugs do to temporarily alleviate the problem?”
28. Answer: D, 79%. Chapter 11, Objective 20; “Explain the sequence of reactions that occur following the binding of glucagon or epinephrine to a heptahelical receptor. Include the terms: glucagon, epinephrine, heterotrimeric G proteins, α-subunit, βγ-complex, GDP, GTP, tethered, lipid anchor, adenylyl cyclase, ATP, cAMP, PPi, and hydrolysis How long does the Gαs protein stay active?.”
29. Answer: E, 83%. Chapter 19, Objective 8; “Given two equations with the Delta Go' for each reaction, be able to add or subtract an equation and determine if the reaction as spontaneous.”

30. Answer: A, 85%. Chapter 19, Objective 16; “How do NAD, FAD, and FMN function?
31. Answer: E, 68%. Chapter 19, Objective 20; “Assume a sudden loss of oxygen supply to a cell. Give a simple scenario (sequence of events) that might lead to cell death (necrosis) and release of enzymes. Use the terms hypoxia, oxidative phosphorylation, ATP concentration, active transport, intracellular Ca2+, swelling, permeability, and creatine kinase.”
32. Answer: D, 22%, Chapter 19, Objective 9; “Given the equation at the bottom of Table 19.2, be able to explain why delta-G can be positive while delta-Go' is negative and vice versa.”
33. Answer: E, 76%. Chapter 20, Objectives 11 ; “How is the rate of the TCA cycle linked to muscle contraction and the utilization of ATP?
34. Answer: B, 86%. Chapter 20, Objective 1; “To describe any pathway or cycle, start with the following paradigm for the TCA cycle; Names; Functions; Substrates; Products; Control Enzymes; Regulation; Compartment; Tissues of Interest;”
35. Answer: C, 58%, Chapter 20, Objective 2; “Name the four dehydrogenase enzymes of the TCA cycle. What are the substrates and products of each reaction?
36. Answer: D, 81%, Chapter 20, Objectives 16 and 17; “Explain how the rate of the pyruvate dehydrogenase complex is related to the rate of utilization of ATP” “ Explain how muscle contraction is related to the rate of the pyruvate dehydrogenase reaction.”
37. Answer: E, 71%. Chapter 21, Objective 15; “Be able to go through the series of events whereby pyruvate dehydrogenase is activated by increased ATP utilization.
38. Answer: B, 64%, Chapter 21, Objective 8; “Be able to state the chemiosmotic theory!
39. Answer: C, 45%, Chapter 21, Objective 17; “What is the difference between an inhibitor of electron transport and an uncoupler of electron transport with respect to NADH utilization, proton pumping, and ATP synthase?
40. Answer: E, 67%. Chapter 21, Objective 16 and 17;” Understand how a chemical uncoupler works. What happens to heat production, proton pumping, ATP synthesis, and NADH utilization following uncoupling?” “What is the difference between an inhibitor of electron transport and an uncoupler of electron transport with respect to NADH utilization, proton pumping, and ATP synthase?”
41. Answer: D, 30%. Chapter 22, Objective 11; “Compare the energy produced from glucose during anaerobic glycolysis with the energy produced in the conversion of glucose to pyruvate during aerobic glycolysis.”
42. Answer: E, 81%. Chapter 22, Objective 23; “Concerning Ivan Applebod: Streptococcus mutans needs energy for growth and cell division. As a result, they also cause dental caries. What is the relationship between the production of energy and dental caries?”
43. Answer: A, 55%, Chapter 22, Objective 14; “Explain the Cori cycle.
44. Answer: B, 90%. Chapter 22, Objectives 21;”Concerning Lopa Pusor; Explain why hemorrhage, anemia, COPD, or any combination of these three might result in lactic acidosis.
45. Answer: E, 38%. Chapter 23, Objective 4; “What are the reactants and products of the fatty acyl CoA synthetase reaction?”
46. Answer: E, 80%. Chapter23, Objective 10; “ Describe the pathway for the synthesis of ketone bodies by naming substrates, the first ketone body made in the pathway, the next two ketone bodies made in the pathway, the intermediate in the pathway that can be used either for ketone body synthesis or cholesterol synthesis, and the enzyme that actually produces the first ketone body as a product. Control? Where does this pathway reside?”
47. Answer: C, 95%, Chapter 23, Objective 2; “How are free fatty acids transported from adipose tissue to muscle or liver cells?
48. Answer: C, 65% Chapter 23, Objectives 8 and 10; “ Be able to name the three metabolites and two important cofactors in the conversion of part of an odd chain fatty acid to a TCA cycle intermediate. (Skip the epimerase reaction.)” “Describe the pathway for the synthesis of ketone bodies by naming substrates, the first ketone body made in the pathway, the next two ketone bodies made in the pathway, the intermediate in the pathway that can be used either for ketone body synthesis or cholesterol synthesis, and the enzyme that actually produces the first ketone body as a product. Control? Where does this pathway reside?”

49. Answer: B, 63%. Chapter 26, Objective 6; “What is the effect of glucagon upon the following metabolic pathways...the storage of glucose in glycogen, the mobilization of glucose from glycogen, the synthesis of fatty acids from glucose in the liver, the synthesis of triacylglycerols in liver and adipose tissue, the mobilization of free fatty acids from adipose tissue, and the mobilization of amino acids from proteins for gluconeogenesis.
50. Answer: C, 46%. Chapter 26, Objective 26; “Concerning Bea Selmass...Explain why a patient with an insulinoma would have fasting hypoglycemia.
51. Answer: E, 37%, Chapter 26, Objective 20; “Concerning Ann Sulin; She has type 2 and her blood insulin levels are within the normal range. Are her B-cells secreting enough insulin? Are her muscle and adipose cells responding normally to insulin?”
52. Answer: D, 92%. Chapter 26, Objective 9;”Know the important events in the synthesis of insulin from synthesis of the preprohormone to precipitation in storage granules.”
53. Answer: D, 79%. Chapter 28, Objective 20; “Concerning Jim Bodie...Jim injected insulin just before exercise. What were the affects upon the pathways and transport mechanisms of the liver and muscle that led to his hypoglycemic coma?
54. Answer: C, 83%, Chapter 28, Objectives 5 and 11; “Describe the pathway for glycogen synthesis from glucose in liver and muscle; Name, Function, Substrates, Products, Control Enzyme, Regulation, Compartment. What is the effect of changes in the insulin, blood glucose or epinephrine upon glycogen synthesis or glycogen degradation in muscle?
55. Answer: D, 81%. Chapter 28, Objective 2;”What are the functions of glycogen in liver and skeletal muscle? Why must glucose-6-phosphate produced from glycogen in muscle enter glycolysis? Why does glucose produced from glycogen in liver usually enter the blood stream instead of glycolysis?
56. Answer: D, 81%. Chapter 28, Objective12; “ In order of their activation, be able to name and give the reason for the activation of all the intermediates in the cAMP cascade in liver. Start with a decrease in the insulin/glucagon ratio or an increase in epinephrine and end with the change in activity of glycogen synthase, phosphorylase kinase and phosphorylase a?”
57. Answer: D, 87%. Chapter 29, Objective 1; “Describe the pentose phosphate pathway ...Names, Functions, Substrates, Product, Control Enzymes, Regulation, Compartment(s), Tissues of interest.
58. Answer: D, 82%, Chapter 29 Objective 3; “What is NADPH used for?
59. Answer: C, 56%, Chapter 29, Objective 5; “Concerning Al Martini; This patient has glucose-6-phosphate dehydrogenase deficiency. Why are red blood cells lysed while other cells of the body remain intact? Why didn't this disease show up earlier in life?
60. Answer: B, 70%, Chapter 29, Objective 4; “Assume that you have a patient that has hemolytic anemia a result of eating fava beans. Name the deficient enzyme and the other enzymes and products in the pathway that leads to the reduction of HOOH. Why didn't this disease show up earlier in life?
61. Answer: D, 80%, Chapter 31, Objective 12; “Name the enzyme that converts glucose-6-phosphate to glucose in liver.”
62. Answer: C, 78%, Chapter 31, Objective 3; “What are the sources of the gluconeogenic precursors and how are they converted into pyruvate, TCA cycle intermediates, or dihydroxyacetonephosphate?
63. Answer: E, 80%. Chapter 31, Objective 25; “ Be able to state the major source of glucose (ingested, glycogenolysis, or gluconeogenesis) used by a sedentary person following ingestion of a meal. For example, at l hour, 4 hours, 16 hours, and 30 hours. Assume that the subject was sedentary. What would happen to this timetable if the person were running a marathon?”
64. Answer: C, 88%. Chapter 31, Objective 24; “Between 3 days and 6 weeks of starvation, what happens to the blood concentrations of glucose, free fatty acids, and ketone bodies? What happens to the total utilization of glucose by the body? What happens to the total utilization of fat by the body? Between 3 days and 6 weeks of starvation, what happens to total urinary nitrogen excretion? Note that total urinary nitrogen is at least 80% urea. Explain this change in urea excretion.”
65. Answer: A, 90%, Chapter 33, Objective 8; “What are the essential fatty acids and why are they essential?
66. Answer: C, 90%. Chapter 33, Objective 16;”In the synthesis of membrane lipids, what is the function of SAM?
67. Answer: A, 56%. Chapter 33, Objective 6;” Where does the elongation of most fatty acids take place?”

68. Answer: E, 60%. Chapter 33, Objective 19; “ Concerning Colleen Lakker; What was the cause of respiratory distress syndrome of this premature infant? What specific compounds are missing? Are any derivatives of phosphatidic acid?”
69. Answer: E, 82%. Chapter 36, Objective 1; “ Describe the pathway for the storage of glucose in the liver in the fed state? How is this pathway regulated.? Are there any possible futile cycles prevented?
70. Answer: E, 60%. Chapter 36, Objective 20; “Concerning Di Beatty who has type I diabetes has developed ketoacidosis...On a molecular level, explain why she has opalescent serum. Why does she have high blood glucose? Why does she have ketonemia?
71. Answer: D, 77%, Chapter 36, Objective 20; “Concerning Di Beatty who has type I diabetes has developed ketoacidosis...On a molecular level, explain why she has opalescent serum. Why does she have high blood glucose? Why does she have ketonemia?
72. Answer: B, 86%. Chapter 36, Objective 15;” What is the control enzyme for the release of free fatty acids during a fast and how is this enzyme regulated?”
73. Answer: C, 96%. Chapter 38, Objective 5;”What are the cofactors for ALT and AST. Are the coenzymes prosthetic groups? What vitamin are the cofactors derived from?
74. Answer: E, 43%. Chapter 38, Objective 18; “Concerning Percy Veere who has hepatitis A; Why would a low protein diet, antibiotics, enemas and lactulose lower his blood ammonium ion level?
75. Answer: C, 89%. Chapter 38, Objective 12; “Know the substrates, products, and five enzymes of the urea cycle. Which compartments are involved? What tissues are involved?
76. Answer: B, 56%, chapter 38, Objective 4; “Be able to write a reaction for AST, ALT, or any other transamination reaction. What is the approximate Keq for these reactions?
77. Answer: C, 79%. Chapter 39, Objective 1; “What is an essential amino acid? Which ones are they?
78. Answer: E, 71%. Chapter 39, Objective 13; “ Concerning Homer Sistine; If he had an inborn error in cystathionine synthase, what would happen to his concentrations of methionine, homocysteine, and cysteine? Why? If his problem had been a deficiency of folate or vitamin B12 , what would you expect to happen to the concentrations of methionine, homocysteine, and cysteine? Why?
79. Answer: C, 76%, Chapter 39, Objective 5; “For each amino acid, be able to say where its catabolic products enter the TCA cycle, the glycolytic/gluconeogenic pathways, or the ketone body pathway.
80. Answer: A, 58%, Chapter 39, Objective 13; “ Concerning Homer Sistine; If he had an inborn error in cystathionine synthase, what would happen to his concentrations of methionine, homocysteine, and cysteine? Why? If his problem had been a deficiency of folate or vitamin B12 , what would you expect to happen to the concentrations of methionine, homocysteine, and cysteine? Why?
81. Answer: D, Estimated 70%, Practice Question 22, Chapter 4, Objective 14; "Regarding the Di Beatty Case; Explain why an increase in a metabolic acid would cause the changes seen in PaCO2 and serum bicarbonate. What would happen to the concentration of CO2 and serum bicarbonate after the insulin injection?"
82. Answer: B, Estimated 70%, Practice question 25, Chapter 6, Objective 16; "Concerning Michael Sichel; To the extent covered in this chapter, explain his disease in terms of amino acids. In the African American population, is the Sickle Cell allele a polymorphism?"
83. Answer: D, Estimated 70%, Practice question 21, Chapter 8, Objective 21; "Be able to name the 6 major classes of enzymes. Given one of the following reactions, be able to match it with one of the 6 major classes of enzyme reactions catalyzed; alcohol dehydrogenase, glucokinase, chymotrypsin, aldolases, triosephosphate isomerase, and pyruvate carboxylase."
84. Answer: B, Estimated 70%, Practice question 24, Chapter 11, Objective 24; "Name the enzyme that synthesizes cAMP, the enzyme that hydrolyses cAMP and the enzyme that is activated allosterically by cAMP. Which of these three enzyme reactions is affected by insulin?"
85. Answer: E, "Estimated 65%, Practice question 4, Chapter 19, Objective 4; "Understand the difference between ΔG and ΔG0!?"
86. Answer: E, Estimated 70%, Practice question 29, Chapter 20, Objective 29; "Concerning Al Martini; Given that a-ketoacids build up in the heart in wet beriberi, develop a scenario that would explain why peripheral vessels dilate and cardiac muscles lose their contractility."

87. Answer: D, Estimated 70%, Practice question 19, Chapter 22, Objective 19; "In cardiac muscle, high adrenalin and high cAMP will activate protein kinase A. High protein kinase A activity will phosphorylate the enzyme phosphofructokinase-2/fructose-2,6-bisphospahtase. How will this effect the activity of phosphofructokinase 1 and the rate of glycolysis?"
88. Answer: E, Estimated 70%, Practice question 10, Chapter 26, Objective 10; "Describe the mechanism of release of insulin from β-cells in response to increased blood glucose. Include the terms; blood glucose, glucose transporter, glucokinase, glycolysis, ATP concentration, ATP sensitive K+ channel, membrane depolarization, calcium concentration, exocytotic vesicle, plasma membrane, fusion, insulin release."
89. Answer: E, Estimated 70%, Practice Question 1, Chapter 29, Objective 1; "Describe the pentose phosphate pathway; Names; Functions; Substrates; Product; Control Enzymes; Regulation; Compartment(s); Tissues of interest."
90. Answer: A, Estimated 70%, Practice Question 11, Chapter 31, Objective 11; "Explain the activation of the fructose-1,6-bisphosphatase during gluconeogenesis. What prevents the reverse reaction and a futile cycle from occurring?"
91. Answer: E, Estimated 70%, Practice Question 12, Chapter 33, Objective 12; " Be able to list the sequence of events from the time epinephrine binds a receptor on the surface of an adipose cell until acetyl CoA is made in muscle or liver. Don't forget the key enzyme that controls the process."
92. Answer: C, Estimated 70%, Practice Question 15, Chapter 38, Objective 15; "Name 3 ways to treat argininosuccinate lyase deficiency and explain their rationale."
93. Answer: B, Estimated 70%, Practice Question 13, Chapter 39, Objective 13; "Concerning Homer Sistine; If he had an inborn error in cystathionine synthase, what would happen to his concentrations of methionine, homocysteine, and cysteine? Why? If his problem had been a deficiency of folate or vitamin B12 , what would you expect to happen to the concentrations of methionine, homocysteine, and cysteine? Why?"