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Enzyme Catalysis and Regulation, Exams of Biochemistry

An overview of various enzyme-catalyzed reactions and their regulatory mechanisms. It covers topics such as proenzymes, catalysis of addition, transfer, and hydrolysis reactions, as well as enzyme regulation through allosterism, feedback control, and isoenzymes. The document also discusses carbohydrate metabolism, including glycolysis, gluconeogenesis, and glycogenesis/glycogenolysis, as well as lipid metabolism and the role of enzymes in these processes. Additionally, it touches on nucleic acid metabolism, including dna replication and repair, and the involvement of enzymes in these pathways. A comprehensive understanding of the diverse functions and regulation of enzymes in various metabolic processes within the human body.

Typology: Exams

2024/2025

Available from 10/12/2024

wilfred-mburu
wilfred-mburu 🇬🇧

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Biochem - Final Exam Review

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  1. Which of the following is representative of transferases? a. Catalyze hydrolysis reaction b. Catalyze addition of two groups across a double bond c. Catalyze oxidation and reduction d. Catalyze joining of two groups e. transfer a group of atoms from one molecule to another - ANSE 2. Which of the following statements about competitive and noncompetitive inhibition is false? a. A competitive inhibitor does not change the Vmas of the enzyme b. A competitive inhibitor decreases the apparent Km for a given substrate c. Increasing the [S[] for a noncompetitive inhibitor results in a decrease in Vmas of the enzyme d. A noncompetitive inhibitor does not change the Km of the enzyme whereas the Vmas of the enzyme is unaffected by a competitive inhibitor - ANSB 3. HIV protease illustrates a example of which of the following types of catalysis? a. Acid-base catalysis b. Catalysis by strain c. Covalent catalysis d. Catalysis by proximity - ANSA 4. In the regulation of enzymes, which of the following represents a regulation process in which different forms of the same enzyme (which differ in amino acid sequence) controls the activity of the enzyme? a. Proenzymes b. Protein modification c. Allosterism d. Isoenzymes e. Feedback control - ANSD 5. Which of the following is representative of ligases? a. Catalyze oxidation and reduction b. Catalyze addition of two groups across a double bond c. Transfer a group of atoms from one molecule to another d. Catalyze joining of two groups e. Catalyze hydrolysis reaction - ANSD 6. Extreme pH can lead to denaturation of the enzyme. True or False? a. True b. False - ANSA 7. Dephosphorylation is catalyzed by enzymes called a. Phosphatase b. Kinase - ANSA 8. Which of the following is representative of oxidoreductases? a. Catalyze addition of two groups across a double bond b. Catalyze joining of two groups c. Catalyze oxidation and reduction d. Catalyze hydrolysis e. Transfer a group of atoms from one molecule to anotion - ANSC 9. An NH3+ group from an amino acid is exchanged with a C=O group of Pyruvate (CH3-CO-COO-) by an enzyme. This enzyme is categorized as? a. Transferase b. Oxidoreductase c. Isomerase d. Lyase - ANSA 10. In the

mechanism of enzyme action, which model assumes that enzymes are rigid molecules? a. Lock and Key model b. Induced fit model - ANSA 11. In which of the following two inhibition mechanisms does the inhibitor molecule bind to another site on the enzyme? a. Competitive Inhibition b. Noncompetitive inhibition - ANSB

  1. Chymotrypsin illustrates an example of which of the following types of catalysis? a. Catalysis by proximity b. Acid-base catalysis c. Covalent catalysis d. Catalysis by strain - ANSC 13. Phosphorylation is catalyzed by enzymes called a. Phosphatase b. Kinase - ANSB 14. In the regulation of enzymes, which of the following represents a regulation process in which the enzyme is manufactured by the body in the inactive form? a. Proenzymes b. Feedback control c. Protein modification d. Allosterism e. Isoenzymes - ANSA 15. Which of the following is representative of isomerases? a. Catalyze addition of two groups across a double bond b. Catalyze isomerization reactions c. Transfer a group of atoms from one molecule to another d. Catalyze oxidation and reduction e. Catalyze hydrolysis reaction - ANSB 16. In which of the following two inhibition mechanisms does the inhibitor molecule fit into the active site cavity in the same way as the substrate does? a. Competitive Inhibitor b. Noncompetitive inhibitor - ANSA 17. In the regulation of enzymes, which of the following represents a regulation process in which the regulator controls the activity of the enzyme? a. Allosterism b. Feedback control c. Proenzymes d. Protein modification e. Isoenzymes - ANSA 18. Glucose and Galactose are epimers of each other or two molecules having the same number of C, H, O but different conformation of the OH group at C#4. If an enzyme converts Galactose into Glucose, which of the following categories would you classify or categorize this enzyme under? a. Transferase b. Oxidoreductase c. Isomerase d. Lyase - ANSC 19. An enzyme converts Acetyl-CoA (CH3-CO-SCoA) into Acetic acid and CoA-SH. Which of the following categories does this enzyme belong to? a. Oxidoreductase b. Hydrolase c. Lyase d. None of these - ANSB 20. An enzyme converts alcohol into an aldehyde. Which of the following enzymes categories would this enzyme be grouped under? a. Lyase b. Oxidoreductase c. Ligase d. Transferase - ANSB 21. Vitamins a. The reduced co-enzyme form of this folate receives one carbon from Ser, Gly, His and is used for the biosynthesis of C#2 and C#8 of Purines? Folic Acid b. This vitamin is required for the remethylation of Homocysteine to methionine? Cobalamin (Vitamin B12) c. This

coenzyme for hydroxylation reactions to form hydroproline and hydroxylysine? Ascorbic Acid (Vit C) d. This Vitamin is required for synthesis of active form of Pyridoxal phosphate (PLP)? Vitamin B6 e. Conversion of Homocysteine to cysteine requires this co-enzyme? PLP (Pyridoxalphosphate) f. The active form of this vitamin serves as a co- enzyme for oxidative decarboxylation of alpha keto glutarate to SuccinylCoA (in the Citric Acid cycle)? Vitamin B1 (Thiamine/ active form: thymine pyrophosphate) g. This vitamin which is a substituted pyridine derivative is used in the production of a co-enzyme that is used for oxidation-reduction react - ANS 22. Which of the following statement about Vitamins is false? a. The active form of Vitamin B9 is required for transfer of one carbon unity in the synthesis of methionine b. Ascorbic acid is the active form of vitamin C that is required for the hydroxylation of proline or lysine c. The active form of Vitamin B7 is used for decarboxylation reactions d. Thiamine provides the active form - thiamine pyrophosphate - which is used as a co-enzyme catalyzing that conversion of pyruvate into acetyl-CoA - ANSC

  1. Which of the following statements about B-complexes is false? a. Thiamine is classified as energy releasing vitamin b. Folic acid is classified as hematopoietic vitamin c. Active form of Vitamin B6 is used in transamination reactions d. Niacin provides the active form for the coenzyme NAD+ which contains the heterocycles - Piperidine - ANSD 24. An enzyme that catalyzes the joining of two molecules in a reaction is categorized as? a. Oxidoreductase b. Lyase c. Hydrolase d. None of these - ANSD 25. Glycogen phosphorylase is used for the breakdown of Glycogen (a glucose containing polysaccharide) and Glycogen synthase is used for the synthesis of Glycogen. Both enzymes can be modified covalently (made active or inactive) by phosphorylation or dephosphorylation. Which of the following statements about the enzymes glycogen phosphorylase (or phosphorylase) and glycogen synthase is True? a. Covalent modification of Glycogen Synthase by Phosphorylation makes the enzyme active (for biosynthesis of Glycogen) b. Covalent modification of Glycogen Phosphorylase by dephosphorylation (or hydrolysis of glycogen phosphorylase) makes the enzyme active (for breakdown of Glycogen) c. Covalent modification of Glycogen Phosphorylase by Phosphorylation makes the enzyme active (for breakdown of Glycogen) - ANSC 26. In the regulation of enzymes, which of the following represents a regulation process in which the addition or removal of a

group controls the activity of the enzyme? a. Isoenzymes b. Allosterism c. Protein modification d. Feedback control e. Proenzyme - ANSC 27. Which of the following is representative of lyases? a. Catalyze joining of two groups b. Catalyze addition of two groups across a double bond c. Catalyze hydrolysis reaction d. Transfer a group of atoms from one molecule to another e. Catalyze oxidation and reduction - ANSB

  1. In the regulation of enzymes, which of the following represents a regulation process in which the formation of the product inhibits an earlier reaction in the sequence? a. Feedback control b. Proenzymes c. Protein modification d. Isoenzymes e. Allosterism - ANSA 29. To activate proenzymes, what needs to be done? a. Polypeptide chains need to be added b. Polypeptide chains need to be removed - ANSB 30. N-acetylneuraminic acid is he combination of pyruvate and which other molecule? a. Glucosamine b. Mannose c. Glucose d. Mannosamine - ANSD 31. In the test for blood glucose, which of the following is formed? a. D-glucuronic acid b. Methyl-m-D-glucopyranoside c. D-gluconic acid d. D-glucitol - ANSC 32. Which of the following reagents is capable of hydrolyzing glycosides? a. Acids b. Water c. Bases d. All of these - ANSA 33. Pair the Blood group types against the sugars in the terminal groups on RBC. a. Blood Group A - Has N-acetylegalactosamine b. Blood Group B - Has Galactose c. Blood Group O - Has neither GalNac or Gal - ANS 34. Complete hydrolysis of which of he following disaccharides yields two different monosaccharides? a. Lactose b. Trehalose c. Sucrose d. Maltose - ANSC 35. What type of organic reaction occurs when glucose is converted to glucuronic acid? a. Oxidation at C1 b. Oxidation at C6 c. Reduction at C6 d. Reduction at C1 - ANSB 36. When fructose adopts a furanose structure, which carbon number in the furanose is the anomeric carbon? a. C2 b. C6 c. C5 d. C1 - ANSA 37. How many chiral carbons are present in the open-chain form (fisher projection) of a ketohexose? a. 3 b. 4 c. 5 d. 6
  • ANSA 38. Which of the following contains beta (1,4) glycosidic bonds? a. Cellulose b. Amylopectin c. Amylose d. All of these - ANSA 39. Under which of the following conditions can monosaccharides be oxidized to uronic acids? a. Enzymatic b. Basic c. Acidic d. None of these - ANSA 40. Which of the following is true about the reducing properties of sugars? a. All monosaccharides and all disaccharides are reducing sugars b. All monosaccharides and all disaccharides are nonreducing sugars c. All monosaccharides and some disaccharides are reducing sugars d. All

monosaccharides and some disaccharides are nonreducing sugars - ANSC 41. This oxidized derivative of a primary -OH group in this aldohexose can be obtained from the lysosomal degradation of glycosaminoglycans (GAGs): a. Glucosamine b. Glucuronic acid c. Gluconate d. Glucitol - ANSB 42. How many chiral carbons are present in the open-chain form (Fisher projection) of an aldopentose? a. 2 b. 3 c. 4 d. 5 - ANSB 43. Which of the following determines blood type B in the ABO blood typing system? a. The presence of both N-acetyl-D-galactosamine and D-galactose antigens b. The presence of only N-acetyl-D-galactosamine c. The presence of only D- galactose d. The absence of both N-acetyl-D-galactosamine and D-galactose - ANSC

  1. The beta (1,4) glycosidic bond is found in which of the following disaccharides? a. Sucrose b. Lactose c. Maltose d. All of these - ANSB 45. The D-form of which of the following amino sugars is commonly found naturally? a. Mannosamine b. Allosamine c. Althrosamine d. None of these - ANSA 46. The alpha (1,2) glycosidic bond is found in which of the following disaccharides? a. Sucrose b. Lactose c. Maltose d. None of these - ANSA 47. Which of the following statements about monosaccharides and their reaction is false? a. Glucuronic acid is the oxidized product of C6 of glucose b. Fructose is not a reducing sugar c. Gluconate is the oxidized product of C1 of glucose d. Mannose is the C2 epimer of glucose - ANSB 48. a. Long, unbranched heteropolysaccharide chains containing repeating disaccharide units describes which of the following polysaccharides? Glycosaminoglycan b. 100 linear chains containing up to 200 disaccharide units are attached to a core protein describes which of the following polysaccharides? Proteoglycans c. Oligosaccharides (glycans) are covalently attached to proteins describes which of the following polysaccharides? Glycoproteins
  • ANS 49. When glucose adopts a pyranose structure, which carbon number in the pyranose form is the anomeric carbon? a. C1 b. C2 c. C5 d. C6 - ANSA 50. Hyaluronic acid is classified as which of the following? a. A polymer of N-acetyl-D-glucosamine only b. A polymer of D-glucuronic acid only c. A polymer of D-glycerate d. A polymer of both D-glucuronic and N-acetyl-D-glucosamine - ANSD 51. Which of the following determines blood type A in the ABO blood typing system? a. The absence of both N- acetyl-D-galactosamine and D-galactose antigens b. The presence of both N-acetyl- D-galactosamine and D-galactose antigens c. The presence of only D-galactose antigen d. The presence of only N-acetyl-D-galactosamine - ANSD 52. Under which of

the following conditions can monosaccharides be oxidized to aldonic acids? a. Neutral b. Basic c. Acidic d. All of these - ANSB 53. An alpha (1,4) glycosidic bond is found in which of the following disaccharides? a. Lactose b. Maltose c. Sucrose d. All of these - ANSB 54. Things: a. Found in cartilage, bind collagen, and hold fibers in a tight and strong network. This describes which of the following GAGs? Chondroitin 4 and 6 sulfate b. Found in corneas. This describes which of the following GAGs? Keratin Sulfates 1 (KS 1) c. Found in the loose connective tissue. This describes which of the following GAGs? Keratin Sulfate 2 (KS2) d. Found in synovial fluid of joins, vitreous humor of the eye. This describes which of the following GAGs? hyaluronic acid e. Found in skin, blood vessels, and heart valves. This describes which of the following GAGs? Dernatan Sulfate f. Serves as an anticoagulant. This describes which of the following GAGs? Heparin g. Extracellular GAG found in the basement membrane and as a ubiquitous component of cell surfaces. This describes which of the following GAGs? Heparan Sulfate - ANS 55. What organic reaction occurs when glucose is converted to glucitol? a. Oxidation at C1 b. Reduction at C6 c. Reduction at C1 d. Oxidation at C6 - ANSC 56. When ribose adopts a furanose structure which carbon is the anomeric? a. C1 b. C2 c. C5 d. C6 - ANSA 57. Which of the following determines blood type O in the ABO blood typing system? a. The absence of both N- acetyl-D-galactosamine and D-galactose antigens b. The presence of both N-acetyl- D-galactosamine and D-galactose antigens c. The presence of only D-galactose antigen d. The presence of only N-acetyl-D-galactosamine - ANSA 58. What organic reaction occurs when glucose is converted to gluconate? a. Oxidation at C6 b. Oxidation at C1 c. Reduction at C1 d. Reduction at C6 - ANSB 59. Glycogen is structurally similar to which of the following polysaccharides? a. Heparin b. Amylose c. Amylopectin d. Cellulose - ANSC 60. Sialic acids are constituents of both glycoproteins and ganglioside. Is this statement true or false? a. True b. False - ANSA

  1. The primary metabolic fate of lactate released from muscle during intense exercise is: a. Transported to liver for replenishment of blood glucose by gluconeogenesis b. Gradual reuptake in muscle during the recovery phase following exercise c. Excretion of lactate in urine d. Conversion to pyruvate - ANSA 62. A patient was doing a self-test to measure glucose concentration after an overnight fast. Serum glucose concentrations was found to be within the normal range. Which

of the following can explain the normal levels of glucose? a. Gluconeogenesis in the liver increased in response to insulin b. Ketogenesis in the liver increased in response to glucagon c. Glycogenolysis in the muscle increased in response to glucagon d. Gluconeogenesis in the liver increased in response to glucagon - ANSD 63. Both glycolysis and gluconeogenesis involve which of the following enzymes: a. Phosphofructokinase-1 b. Pyruvate carboxylase c. Hexokinase d. Aldolase - ANSD 64. Which of the following vitamins does not participate in the oxidative decarboxylation of pyruvate to acetyl-CoA? a. Thiamine b. Niacin c. Biotin d. Riboflavin - ANSC 65. Insulin promotes hypoglycemia by a mechanism including all of the following except: a. Stimulating glycogen phosphorylase enzyme b. Inducing the synthesis of key glycolytic enzymes c. Decreasing levels of cAMP d. Repressing the synthesis of key gluconeogenic enzymes - ANSA 66. Which of the following amino acids is the major contributor of hepatic gluconeogenesis? a. Leucine b. Alanine c. Lysine d. Glutamine

  • ANSB 67. The following enzymes catalyze a decarboxylation reaction except: a. Pyruvate carboxylase b. Pyruvate dehydrogenase c. Isocitrate dehydrogenase d. Alpha-ketoglutarate dehydrogenase - ANSA 68. Which of the following statements about the production of NADH in the conversion of pyruvate to PEP and lactate to PEP is false? a. When lactate is converted to PEP, 1 mole of NADH is produced in the cytosol b. When pyruvate is converted to PEP in the cytosol, 2 moles of NADH are produced in the overall reaction c. When lactate is converted to PEP, 1 mole of NADH is produced in the mitochondria when Lactate is converted to pyruvate d. When pyruvate is converted to PEP in the cytosol, 1 mole of NADH is produced in the cytosol and 1 mole of NADH is produced in the mitochondria - ANSC 69. Should there be a deficiency of pyruvate carboxylase, which of the following molecules can be used as a substrate for gluconeogenesis? a. Alanine b. Pyruvate c. Glycerol d. Lactate
  • ANSC 70. Glucose-6-phosphate is involved in which of the following patways: a. Pentose phosphate pathway b. Glycolysis c. Gluconeogenesis d. All the ones listed - ANSD 71. If a person has an impaired lactate dehydrogenase, gluconeogenesis can still proceed but would need one of the following enzymes to provide the reducing equivalent for Glyceraldehyde 3 Phosphate dehydrogenase (Gly3PD). Which of the following reactions can provide the reducing equivalents? a. Pyruvate carboxylase b. Glucose-6-phosphate dehydrogenase c. Malate dehydrogenase d. PEP carboxykinase
  • ANSC 72. Which of the following statement is true of TCA cycle? a. Enzymes are located in cytosol b. It participates in the synthesis of glucose from pyruvic acid c. Two NADH are produced per turn d. It requires coenzyme biotin, FAD, NAH, and coenzyme-A - ANSB 73. Gluconeogenesis can proceed from all of the following except: a. Palmitic acid b. Oxaloacetate c. Pyruvate d. Propionyl-CoA - ANSA 74. McArdle syndrome involves a deficiency of which of the following enzymes? a. Debranching enzyme b. Muscle phosphorylase c. Hepatic phosphorylase d. Hepatic glycogen synthase - ANSB 75. NADPH is used by which of the following to protect erythrocytes from lysis: a. Glutathione b. Cholesterol c. NADP d. Cysteine - ANSA 76. The principal source of glucose after an overnight fast is: a. Glycogenolysis b. Glycogenesis c. Gluconeogenesis d. Glycolysis - ANSC 77. The purpose of the Cori cycle is to shift the metabolites in which of the following directions? a. Muscle to liver b. Liver to muscle c. Brain to liver d. Liver to brain e. Cardiac to skeletal muscle - ANSA 78. Deficiency of glucose-6-phosphate dehydrogenase causes: a. Galactosemia b. Hypoglycemia c. Cataract d. Hemolytic anemia - ANSD 79. During early fasting, glycogen is used as a source of glucose for the blood. After liver glycogen is depleted which of the following occurs? a. Triacylglycerols in adipose tissue are converted into glucose in the liver using the Acetyl-CoA from fatty acids b. Muscle glycogen continues to be used as a source of glucose for the blood c. Liver fatty acids are degraded into acetyl-CoA for blood glucose d. Amino acids of muscle proteins are used to synthesis glucose in the liver - ANSD 80. In erythrocytes, the end product of glycolysis is: a. 2,3-bisphosphoglycerate b. Lactate c. Acetyl-CoA d. Pyruvate - ANSB
  1. Gluconeogenesis occurs in which of the following: a. Lungs b. Erythrocytes c. Heart d. Liver - ANSD 82. In a patient with galactosemia who is on a galactose free diet, the D-galactose that is required for cell membrane and other biopolymers is formed by: a. Epimerization of D-fructose b. Epimerization of glucose-6-phosphate c. Epimerization of UDP-glucose d. Isomerization of glucose-1-phosphate - ANSC 83. In skeletal muscle, glycogen synthesis occurs during: a. Contraction b. Well-fed state c. Increased level of insulin d. Relaxation - ANSD 84. The hormone that does not stimulate hepatic glycogenolysis is which of the following? a. Glucagon b. Thyroxine c. Epinephrine d. Cortisol - ANSC 85. The following hormones have hyperglycemic effect except: a. Thyroid hormone b. Glucagon c. Epinephrine d. Insulin - ANSD 86.

Essential pentosuria is due to metabolic defect in which of the following: a. Uronic acid pathway b. Glycogenolysis c. Pentose phosphate pathway d. Glycolysis - ANSA

  1. If you plan to state a low carb and protein rich diet, which of the following components or immediate metabolites can be sued to help maintain adequate serum glucose concentration? a. Glycerol b. Acetoacetate c. Hydroxybutyrate d. Palmitate - ANSA 88. Which of the following transformation or reactions to make glucose cannot take place in the human body? a. Transformation of lactate into glucose b. Transformation of propionyl-CoA into glucose c. Transformation of glycerol into glucose d. Transformation of acetyl-CoA into glucose - ANSD 89. Muscle glycogen is not available for maintenance of blood glycose concentration because: a. Muscle lacks glucose-6-phosphate activity b. Muscle lacks glucose transporter GLUT- 4 c. Muscle lacks glucagon receptors d. There is insufficient glycogen in muscle - ANSA 90. Which of the following actions by the hormones/allosteric molecules will increase the activity of the liver to carry out gluconeogenesis during starvation? a. Activation of glucose-6-phosphatse by insulin b. Inhibition of glucokinase by AMP c. Inhibition of fructose-1,6-bisphosphatase by F1,6BP d. Activation of PEP carboxykinase synthesis by glucagon e. Activation of pyruvate kinase by insulin - ANSD 91. When lactate is the substrate for gluconeogenesis, which reaction pathway is followed? a. Oxidation of lactate to pyruvate followed by decarboxylation to OAA and then carboxylation and phosphorylation by GTP to PEP b. Oxidation of lactate to pyruvate followed by carboxylation to OAA and then reduction to Malate c. Oxidation of lactate to pyruvate followed by carboxylation to OAA and then decarboxylation and phosphorylation by GTP to PEP d. Reduction of lactate to pyruvate followed by carboxylation of OAA and then reduction to malate - ANSC 92. The following are the function of the pentose phosphate pathway except: a. Coverts glucose to galactose b. Produced NADPH c. Interconverts hexoses and pentoses d. Supplies ribose-5-phosphate - ANSA 93. Deficiencies in the enzyme glucose-6- phosphatase will result in: a. Increased hepatic glycogen accumulation b. Decreased skeletal muscle glycogen accumulation c. Decreased glycogen production d. Hyperglycemia - ANSA 94. The glucose-6-phosphate dehydrogenase deficiency causes hemolytic anemia due to lack of: a. NADP b. NADPH c. Pentoses d. Cholesterol - ANSB 95. The major fuel for the brain after prolonged starvation is: a.

Glucose b. Fatty acids c. Glycerol d. Ketone bodies - ANSD 96. Which of the following compounds can be used for gluconeogenesis? a. A-hydroxybutyrate b. Acetoacetate c. Palmitate d. Glycerol - ANSD 97. When pyruvate is the substrate for gluconeogenesis, which reaction pathway is followed? a. OAA is transaminated to aspartate b. OAA is reduced to malate c. OAA is oxidized to malate d. OAA is converted to phosphoenolpyruvate - ANSB 98. Which of the following is a hyperglycemic hormone that is secreted by the pancreas? a. Epinephrine b. Insulin c. Growth hormone d. Glucagon - ANSD 99. Von Gierke's disease is characterized by deficiency of the enzyme: a. Phosphoglucomutase b. Glucokinase c. Glycogen synthase d. Glucose-6-phosphatase - ANSD 100. The major fate of glucose-6- phosphate in tissues in a well-fed state is: a. Hydrolysis of glucose b. Conversion to glycogen c. Conversion to ribulose-5-phosphate d. Isomerization to fructose-6- phosphate - ANSB 101. Which of the following statements in summary of fructose metabolism is false? a. Glyceraldehyde is converted to glycerol using alcohol dehydrogenase b. Aldolase B converted fructose-1-phosphate to glyceraldehyde and DHAP c. Deficiency of aldolase B can cause severe hypoglycemia, jaundice, hyperuricemia and more d. Essential fructosuria is because of deficiency of fructokinase which converts fructose to fructose-6-phosphate - ANSD 102. Hypoglycemia promotes the immediate secretion of which of the following hormones/neurotransmitters except: a. Insulin b. Glucagon c. Epinephrine d. Norepinephrine - ANSA 103. In the regulation of gluconeogenesis during fasting, which of the following does not increase? a. cAMP b. Acetyl-CoA c. Protein Kinase A activity d. Pyruvate kinase activity - ANSD 104. The G6PH deficiency causes hemolytic anemia due to lack of which of the following: a. NAD+ b. NADH c. NADPH d. NADP+ - ANSC 105. Glycogen phosphorylase activity will not be inhibited by which of the following molecules? a. ATP b. Glucose-6-phosphate c. AMP (in muscle) d. Glucose - ANSC 106. Which one of the following pathways or conversions DOES NOT produce NADPH required for reductive biosynthesis? a. Isocitrate to alpha-ketoglutarate by isocitrate dehydrogenase b. Oxaloacetate to malate by malate dehydrogenase c. Malate to pyruvate by malic enzyme d. Glucose-6-phophate to 6-phosphgluconate by G6PD - ANSB 107. In the oxidative phosphorylation process, which of the following does not act as a poison for cytochrome c oxidase? a. Malonate b. H2S c.

Cyanide d. Carbon Monoxide - ANSA 108. In the regulation of glycolysis in the well- fed state, which of the following does not increase? a. Blood glucose level b. Fructose-2,6,bisphosphate c. Release of glucagon d. Protein phosphatase activity - ANSC 109. Glucagon and epinephrine will decrease the activity of which of the following: a. Gluconeogenesis b. Ketogenesis c. Glycogenolysis d. Glycogenesis - ANSD 110. In the regulation of glycolysis during fasting, which of the following does not increase? a. cAMP b. Release of glucagon c. Protein kinase activity d. Fructose- 2,6-bisphosphate - ANSD 111. Pyruvate is converted into which amino acid in the muscle before being transported to the liver? a. Alanine b. Aspartate c. Glutamine d. Glutamate - ANSA 112. Excess ammonia from the catabolism of amino acid is transported to the liver as which of the following molecules? a. Alanine b. Pyruvate c. Glutamate d. Glutamine - ANSD 113. Which of the following statements about biosynthesis of various amino acids is false? a. Dopamine beta hydroxylase converts dopamine into norepinephrine b. Tryptophan hydroxylase converted tryptophan into 5-hydroxytryptophan c. Tyrosine hydroxylase converts tyrosine into DOPA d. Phenylethanolamine N-methyltransferase (PNMT) converts epinephrine into norepinephrine - ANSD 114. In the urea cycle, arginosuccinate is converted by arginosuccinate lyase into arginine and which other molecule? a. Aspartate b. Succinate c. Fumarate d. Glutamate - ANSC 115. Reductive amination of alpha- ketoglutarate occurs under what conditions? a. When ammonia levels are high b. When NAD+/NADPH is high c. When ammonia levels are low d. When glutamate levels are high - ANSA 116. Which of the following statements is false? a. Dopamine is oxidized to Vanillymandelic acid using COMT and MAO b. Dopamine is oxidized to Homovanillic acid using COMT and MAO c. Norepinephrine is oxidized into Homovanillic acid using COMT and MAO d. Epinephrine is oxidized to Vanniillymandelic acid using COMT and MAO - ANSA 117. Enzyme AST is present in many tissues. The enzyme catalyzes which of the following conversions? a. Alanine to alpha-ketoglutarate b. Aspartate to alpha-ketoglutarate c. Aspartate to Oxaloacetate d. Asparagine to alpha-ketoglutarate - ANSC 118. Which of the following statements about biosynthesis of amino acids is false? a. Alanine is synthesized from pyruvate by alanine aminotransferase b. Aspartate is synthesized from oxaloacetate by aspartate aminotransferase c. Serine is synthesized from

glycine by glycine hydroxymethyl transferase d. Glutamine is synthesized from glutamate by glutamine synthase - ANSC 119. Which of the followings statements is false? a. Glycine and succinyl-CoA are required for biosynthesis of the pyrrole unit required for Heme synthesis b. Glycine and arginine are condensed to form creatine c. Bilirubin is a reduced produced of Biliverdin d. MAO reduce the monoamines in catecholamines to an aldehyde or an acid group - ANSD 120. Glutamine is converted into glutamate using which of the following enzymes? a. Glutamine synthetase b. Glutamate dehydrogenase c. Gluaminase - ANSC 121. In the urea cycle, Citrulline combines with which amino acid to form arginosuccinate? a. Aspartate b. Fumarate c. Glutamate d. Succinate - ANSA 122. Which of the following statements about the diseases listed below is false? a. PKU is the result of the defect in tyrosine hydroxylase b. Maple syrup urine disease is because of the deficiency of BCKD c. Albinism refers to a defect in tyrosine metabolism d. A deficiency in dihydrobiopterin reductase results in decreased synthesis of catecholamines and serotonin - ANSA

  1. Which of the following statements about clinically important amino acids if false? a. Histidine is the precursor of Histamine and elevated levels of Histidine (Histidenemia) is the result of the deficiency in histidase b. Methionine is the precursor of Cysteine c. Phenylalanine is the precursor of tyrosine and elevated levels of phenylalanine is the result of the deficiency of the enzyme phenylalanine oxidase d. Arginine is the precursor of Nitric oxide - ANSC 125. Which of the following amino acid derivative present in protein can result in the protein having a longer half-life? a. Proteins with serine at the N-terminal b. Proteins with acetylated alanine at the N-terminal c. Proteins with arginine at the N-terminal d. Proteins with serine at the C-terminal - ANSA 126. Which of the following statements about the category of amino acids is false? a. Leucine is glucogenic and ketogenic b. Lysine is exclusively ketogenic c. Tryptophan is both glucogenic and ketogenic d. Isoleucine is both ketogenic and glucogenic - ANSA 127. An enzyme without a cofactor is referred to as a. Apoenzyme b. Co-factor c. Coenzyme - ANSA 128. Which of the following is representative of ligases? a. Catalyze hydrolysis reaction b. Catalyze addition of two groups across a double bond c. Catalyze joining of two groups d. Transfer a group of atoms from one molecule to another e. Catalyze oxidation and reduction - ANSC 129. Which of the following are common co-factors? a. Manganese b. Carbon c.

Phosphorus d. Cobalt - ANSA 130. In the regulation of enzymes, which of the following represents a regulation process in which different forms of the same enzyme (which differ in amino acid sequence) controls the acitivity of the enzyme? a. Isoenzyme b. Proenzymes c. Feedback control d. Allosterism e. Protein modification - ANSA 131. A ________ is a non-protein chemical compound that is tightly bound to an enzyme a. Co-factor b. Factor c. Coenzyme d. Apoenzyme - ANSA 132. Chymotrypsin illustrates an example of which of the following types of catalysis? a. Covalent catalysis b. Catalysis by proximity c. Catalysis by strain d. Acid-base catalysis

  • ANSA 133. In the regulation of enzymes, which of the following represents a regulation process in which the regulator controls the activity of the enzyme? a. Feedback control b. Allosterism c. Proenzymes d. Isoenzymes e. Protein modification
  • ANSB 134. In which of the following two inhibition mechanism does the inhibitor molecule fit into the active site cavity in the same way as the substrate does a. Non- competitive inhibition b. Competitive inhibition - ANSB 135. Which of the following is representative of isomerases a. Catalyze addition of two groups across a double bond b. Catalyze oxidation and reduction c. Catalyze hydrolysis reaction d. Transfer a group of atoms from one molecule to another e. Catalyze isomerization reactions - ANSC 136. Extreme pH can lead to denaturation of the enzyme. True or false? a. False b. True - ANSB 137. An enzyme that catalyzed the joining of two molecules in a reaction is categorized as? a. Lyase b. None of these c. Hydrolase d. Oxidoreductase - ANSB 138. When cofactors are tightly bound to the enzyme they are called ______. a. Co-enzymes b. Prosthetic groups c. Apoenzyme - ANSB 139. Which of the following is representative of oxidoreductases a. Catalyze addition of two groups across a double bond b. Catalyze joining of two groups c. Catalyze hydrolysis reaction d. Catalyze oxidation and reduction e. Transfer a group of atoms from one molecule to another - ANSD 140. Which of the following is a trivial names retained for enzymes (more than one answer): a. Trypsin b. Glycosidase c. Pepsidase d. Pepsin e. Ligase - ANSA 141. In the regulation of enzymes, which of the following represents a regulation process in which the enzyme is manufactured by the body in the inactive form? a. Isoenzymes b. Allosterism c. Feedback control d. Proenzymes e. Protein modification - ANSD 142. Glucose and galactose are epimers of each other or two molecules having the same number of C,H, O but different conformation of the OH

group at C#4. If an enzyme converts galactose into glucose, which of the following categories would you classify or categorize this enzyme under? a. Oxidoreductase b. Lyase c. Transferase d. Isomerase - ANSD 143. An NH3+ group from an amino acid is exchanged with a C=O group of pyruvate (CH3-CO-COO) by an enzyme. This enzyme is categorized as? a. Transferase b. Lyase c. Oxidoreductase d. Isomerase - ANSA 144. A metal ion that is associate reversibly with an enzyme is considered as which of the following? a. Cofactor b. Coenzyme - ANSA 145. Phosphorylation is catalyzed by enzyme called as _____. a. Kinase b. Phosphatase - ANSA 146. HIV protease illustrates an example of which of the following type of catalysis? a. Covalent catalysis b. Catalysis by proximity c. Catalysis by strain d. Acid-base catalysis - ANSD

  1. When cofactors are loosely bound to the enzyme they are called ______. a. Apoenzyme b. Co-enzymes c. Prosthetic group - ANSB 148. In the regulation of enzymes, which of the following represents a regulation process in which the formation of the product inhibits an earlier reaction in the sequence? a. Protein modification b. Isoenzymes c. Proenzymes d. Feedback control e. Allosterism - ANSD
  2. Which of the following statements about B-complexes is false? a. Niacin provides the active form for the co-enzyme NAD+, which contains the heterocycle - Pipieridine b. Thiamine is classified as energy releasing vitamin c. Folic acid is classified as hematopoietic vitamin d. Active form of Vitamin B6 is used in transamination reactions - ANSA 150. Dephosphorylation is catalyzed by enzymes called as _______ a. Phosphatase b. Kinase - ANSA 151. Which of the following is true of enzymes (more than one answer) a. They are scheleroproteins b. They are globular proteins c. They are catalysts that increase the rate of reaction d. They are not specific in action - ANSB AND C 152. The common cofactors in an enzyme is a. Non-metal ion b. Metal ion - ANSB 153. Which of the following are common coenzymes (more than 1 answer) a. Vitamin B12 b. Vitamin C c. Manganese ion d. Cobalt ion - ANSA AND B 154. Which of the following statements about vitamins is false? a. The active form of vitamin B7 is used for decarboxylation reaction b. The active form of vitamin B9 is required for transfer of one carbon unit in the synthesis of methionine c. Thiamine provides the active form - Thiamine pyrophosphate which is used as a co-enzyme catalyzing the conversion of pyruvate into Acetyl CoA d. Ascorbic acid is the acid form of vitamin C that is required for the hydroxylation of

proline or lysine - ANSA 155. Which of the following is true of enzymes? a. It changes the activation energy b. It changes the dGo (Gibbs free energy) of a reaction c. It changes the energy of the reactants d. It changes the energy of the product - ANSA

  1. In the mechanism of enzyme action, which model assumes that enzymes are rigid moleules a. Lock and key model b. Induced fit model - ANSA 157. Which of the following statements about competitive and noncompetitive inhibition is false? a. A competitive inhibitor decreases the apparent Km for a given substrate b. Increasing the [S] for a noncompetitive inhibitor results in a decrease in Vmax of the enzyme c. A competitive inhibitor does not change the Vmax of the enzyme d. A noncompetitive inhibitor does not change the Km of the enzyme whereas the Vmax of the enzyme is unaffected by a competitive inhibitor - ANSA 158. Many coenzymes cofactors and prosthetic groups are derivatives of which of the following? a. Fat soluble vitamins b. Water soluble vitamins - ANSB 159. The active site on the enzymes contains _____ a. Carbohydrates b. Lipids c. Amino acids - ANSC 160. Enzyme activity _____ regulated a. Cannot be b. Can be - ANSB 161. Which of the following is representative of lyases a. Catalyze oxidation and reduction b. Transfer a group of atoms from one molecule to another c. Catalyze addition of two groups across a double bond d. Catalyze joining of two groups e. Catalyze hydrolysis reaction - ANSC 162. Enzymes can work at any pH value. True or false? a. False b. True - ANSA 163. In the regulation of enzymes, which of the following represents a regulation process in which the addition or removal of a group controls the activity of the enzymes? a. Protein modification b. Isoenzymes c. Allosterism d. Proenzymes e. Feedback control - ANSA 164. Enzymes change the energy of reactants or products of a reaction and thereby increase the reaction rate. True or false? a. False b. True - ANSA 165. Which of the following is presentative of transferase a. Catalyze oxidation and reduction b. Transfer a group of atoms from one molecule to another c. Catalyze hydrolysis reaction d. Catalyze addition of two groups across a double bond e. Catalyze joining of two groups - ANSB 166. An enzyme converts alcohol into an aldehyde. Which of the following enzymes categories would this enzyme be grouped under? a. Transferase b. Oxidoreductase c. Lyase d. Ligase - ANSB 167. To activate proenzymes, what needs to be done? a. Polypeptide chains need to be removed b. Polypeptide chains need to be added - ANSA 168. In which of the following two

inhibition mechanisms does the inhibitor molecule bind to another site on the enzyme a. Non-competitive inhibition b. Competitive inhibition - ANSA 169. What is the effect of enzymes on activation energy? a. Reduces activation energy b. Increases activation energy - ANSA 170. An enzyme converts Acetyl CoA into acetic acid and CoA-SH. Which of the following categories does this enzyme belong to? a. Hydrolase b. Oxidoreductase c. None of these d. Lyase - ANSA 171. Cofactors change their oxidation states during a reaction and return back to their original oxidation state. True or false? a. True b. False - ANSA 172. When a ketohexose such as fructose adopts the furanose structure which atoms are connected by an oxygen atom? a. C- and C-6 b. C-2 and C-6 c. C-1 and C-5 d. C-2 and C-5 - ANSD 173. When an aldohexose such as glucose adopts the pyranose structure which atoms are connected by an oxygen atom? a. C-1 and C-5 b. C-2 and C-6 c. C-2 and C-5 d. C-1 and C-6 - ANSA 174. Hyaluronic acid is which of the following? a. An oligosaccharide b. A polymer of N- acetyl-D-glucosamine only c. A polymer of D-glucuronic acid only d. A polymer of both D-glucuronic acid and N-acetyl-D-glucoamine - ANSD 175. Under which of the following conditions can monosaccharides be oxidized to aldonic acids? a. Neutral b. All of these c. Basic d. Acidic - ANSC 176. Which sugar is starting material used by plants to synthesize vitamin C/ a. D-fructose b. L-glucose c. L-fructose d. D-glucose - ANSD 177. Under which of the following conditions can monosaccharides be oxidized to uronic acids? a. Acidic b. Basic c. None of these d. Enzymatic - ANSD 178. Which of the following is true of the spatial distribution of the hydroxyl groups of alpha-D- glucopyranose? a. The hydroxyl on C-1 is equatorial, those on C-2, C-3 and C-4 are axial b. They are all in equatorial positions c. They are all in axial positions d. The hydroxyl on C-1 is axial, those one C-2, C-3 and C-4 are equatorial - ANSD 179. Insulin is a polysaccharide of which of the following? a. Glucose b. Fructose - ANSB 180. Sialic acids are constituents of both glycoproteins and ganglioside. Is this statement true or false? a. True b. False - ANSA 181. Which of the following determines blood type A in the ABO blood typing system? a. The presence of only D-galactose antigen b. The presence of only N-acetyl-D-galactosamine antigen c. The presence of both N- acetyl-galactosamine and D-galactosamine antigens d. The absence of both N-acetyl- D-galactosamine and D-galactose antigens - ANSB 182. N-acetylneuraminic acid is the combination of pyruvate and which other molecule? a. Glucose b. Glucosamine

c. Mannose d. Mannosamine - ANSD 183. In the test for blood glucose which of the following is formed? a. D-gluconic acid b. Methyl-m-D-glucopyranoside c. D-glucitol d. D-glucuronic acid - ANSA 184. Which of the following are components of glycoproteins, gangliosies and glycoaminoglycans? a. Glucitol b. Glucosamine c. Glucouronic acid d. Gluconate - ANSC 185. An alpha 1?2 glycosidic bond is found in which of the following? a. Lactose b. None of these c. Sucrose d. Maltose - ANSC 186. What is the relationship between the number of stereocenters in a monosaccharide in its open-chain and ring structures? a. The open-chain form contains one less stereocenter than does the ring b. The open-chain form contains ones more stereocenter than does the ring c. There is no general relationship, each case must be considered separately d. The two structures contain the same number of stereocenters - ANSA 187. Which of the following occurs when a monosaccharide is converted to an amino sugar? a. An amino group replaces a hydroxyl group b. An amino group replaces a ketone carbonyl c. An amino group replaces an aldehyde carbonyl d. Any of the above, it depends on the identity of the monosaccharide - ANSA 188. Which of the following contains beta 1?4 glycosidic bonds? a. All of these b. Amylopectin c. Cellulose d. Amylose - ANSC 189. Which carbon is the site of reaction when glucose reacts to form a glucoside? a. C-5 b. C-2 c. C-6 d. C-1 - ANSD

  1. Glycogen is structurally similar to which of the following? a. Cellulose b. None of these c. Amylopectin d. Amylose - ANSC 191. Glycosides are examples of which class of compounds? a. Acetals b. Esters c. Hemiacetals d. Ethers - ANSA 192. When ribose adopts furanose structure which carbon is the anomeric carbon? a. C-5 b. C-6 c. C- d. C-1 - ANSD 193. Which of the following reacts with sugars to form glycosides? a. Amines b. Water c. Alcohols d. Hemiacetals - ANSC 194. Complete hydrolysis of which of the following disaccharides yields a single monosaccharide? a. Sucrose b. Lactose c. Maltose d. None of these - ANSC 195. When glucose adopts a pyranose structure which carbon is the anomeric carbon? a. C-5 b. C-1 c. C-6 d. C-2 - ANSB 196. How many chiral carbons are present in the open-chain form of a ketohexose? a. 4 b. 6 c. 3 d. 5 - ANSC 197. Where is glycogen stored? a. Only in the liver b. In both liver and muscles, but largely in the liver c. Only in the muscles d. In both the liver and muscles with approximately equal amounts in both - ANSD 198. What reaction occurs when glucose is converted to glucitol? a. Reduction at C-1 b. Oxidation at C-

c. Reduction at C-6 d. Oxidation at C-6 - ANSA 199. Which of the following is true of glucitol? a. It exists as both ring and open-chain structures with the open-chain structure predominating b. It exists only as a ring structure c. It exists only as an open-chain structure d. It exists as both ring and open-chain structures with the ring structure predominating - ANSC 200. Including pairs of enantiomers, how many different 2-ketohexoses are there? a. 2 b. 8 c. 16 d. 4 - ANSB 201. When fructose adopts a furanose structure which carbon is the anomeric carbon? a. C-6 b. C-1 c. C- d. C-5 - ANSC 202. Which of the following statements is false? a. Mannose is the C- epimer of glucose b. Gluconate is the oxidized product of C-1 of glucose c. Glucouronic acid is the oxidized product of C-6 of glucose d. Fructose is not a reducing sugar - ANSD 203. Which of the following are components of glycoptoreins, gangliosides and glycosaminoglycans? a. Glucitol b. Gluconate c. Glucosamine d. Glucouronic acid - ANSD 204. Which of the following explains why ketoses are reducing sugars? a. Under basic conditions they are converted to aldoses b. Under acidic conditions they are converted to aldoses c. Neither a nor b d. Both a and b - ANSA 205. The D-form of which of the following amino sugars is commonly found naturally? a. Althrosamine b. None of these c. Mannosamine d. Allosamine - ANSC

  1. Which of the following is true about the reducing properties of sugars? a. All monosaccharides and some disaccharides are reducing sugars b. All monosaccharides and all disaccharides are nonreducing sugars c. All disaccharides and some monosaccharides are nonreducing sugars d. All monosaccharides and all disaccharides are reducing sugars - ANSA 207. Which of the following is true of the spatial distribution of the hydroxyl groups of beta-D-glucopyranose? a. They are all in axial b. The hydroxyl on C-1 is equatorial, those C-2, C-3 and C-4 are axial c. They are all in equatorial positions d. The hydroxyl on C-1 is axial, those on C-2, C-3 and C- are equatorial - ANSC 208. When an aldopentose such as ribose adopts the furanose structure which atoms are connected by an pxygen atom? a. C-2 and C-4 b. C-2 and C-3 c. C-1 and C-4 d. C-1 and C-3 - ANSC 209. A beta 1?4 glycosidic bond is found in which of the following? a. Lactose b. Maltose c. Sucrose d. All of these - ANSA 210. Which of the following is true of the alpha and beta anomers of glucose? a. They are equally stable b. They both rotate light to the right, but not to the same extent c. Neither a nor b - ANSB 211. Which of the following determines blood type B in the

ABO blood typing system? a. The presence of only D-galactose antigen b. The presence of only N-acetyl-D-galactosamine antigen c. The presence of both N-acetyl- galactosamine and D-galactosamine antigens d. The absence of both N-acetyl-D- galactosamine and D-galactose antigens - ANSA 212. Which carbon is the site of reaction when fructose reacts to form a fructoside? a. C-6 b. C-1 c. C-2 d. C-5 - ANSC

  1. Which of the following determines blood type O in the ABO blood typing system? a. The presence of only D-galactose antigen b. The presence of only N- acetyl-D-galactosamine antigen c. The presence of both N-acetyl-galactosamine and D-galactosamine antigens d. The absence of both N-acetyl-D-galactosamine and D- galactose antigens - ANSD 214. Which of the following reagents is capable of hydrolyzing glycosides? a. Bases b. Water c. All of these d. Acids - ANSD 215. How many chiral carbons are present in the open-chain form of an aldopentose? a. 5 b. 4 c. 2 d. 3 - ANSD 216. What reaction occurs when glucose is converted to glucuronic acid? a. Oxidation at C-6 b. Oxidation at C-1 c. Reduction at C-1 d. Reduction at C-6 - ANSA 217. In sucrose, which of the following describes the glycosidic bond between C-1 of glucose and C-2 fructose? a. For fructose it is alpha and for glucose it is beta b. For both fructose and glucose it is alpha c. For both fructose and glucose it is beta d. For fructose it is beta and glucose it is alpha - ANSD 218. The D-form of which of the following amino sugars is not commonly found naturally? a. Glucosamine b. Galactosamine c. Mannosamine d. Ribosamine - ANSD 219. The formation of a glycoside from a sugar is an which of the following reactions? a. Reduction b. Condensation c. Hydrolysis d. Oxidation - ANSB 220. In an ATP molecule, the heterocyclic base is not made from which of the following amino acid (or which of the following amino acids do not take part in the biosynthesis of a purine molecule)? a. Gln b. Asn c. Gly d. Asp - ANSB 221. ATP synthase conducts which of the following reactions? a. ADP to ATP b. ATP to ADP - ANSA 222. Oligomycin inhibits which of the following reactions? a. ADP to ATP b. ATP to ADP - ANSA 223. Which of the following statements is false? a. Catalase hydrolyzes H2O2 to O2 and H2O b. Oxidases uses atmospheric oxygen from oxidation reactions c. Dehydrogenases uses atmospheric oxygen for oxidation reactions d. Peroxidases hydrolyzes H2O2 to H2O - ANSC 224. H2S, CO and cyanide inhibit which of the following complexes? a. Complex 1 b. Complex 3 c. Complex 4 d. Complex 2 - ANSC 225. In the citric acid cycle, when

malate is oxidized to oxaloacetate, which of the following co-enzymes is used? a. FAD b. NAD+ - ANSB 226. One mole of QH2 reduces how many moles of CytC? a. 3 b. 1 c. 4 d. 2 - ANSD 227. Which of the following is the is the greatest quantitative source of the phosphate group? a. Phosphagens b. Oxidative phosphorylation c. Citric acid cycle d. Glycolysis - ANSB 228. Which of the following conversions occur in Complex 2? a. Fumarate to succinate b. FADH2 to FAD c. Succinate to fumarate d. NADH to NAD - ANSC 229. Which of the following statements about ATP is false? a. The ribose sugar is connected to the N-9 carbon of the heterocyclic base b. The phosphoric anhydride group is stabilized by Mg+@ ion c. It contains two phosphate ester groups d. It contains two phosphoric anhydride groups - ANSC 230. H2S, CO and cyanide inhibit which of the following complexes? a. Complex 3 b. Complex 2 c. Complex 1 d. Complex 4 - ANSD 231. In which of the following complexes (or enzyme complexes) is the Q (Ubiquinone or Co-Q) reduced? a. None of the options listed b. Complex 1,2, and 3 c. Complex 1,2,3, and 4 d. Complex 1 and 2 - ANSD 232. One mole of QH2 reduces how many moles of CytC? a. 1 b. 2 c. 4 d. 3 - ANSB 233. ATP synthase conducts which of the following reactions? a. ADP to ATP b. ATP to ADP - ANSA 234. Complex 2 refers to which of the following enzyme system? a. NADH-Q oxidoreductase b. CytC oxidase c. None of the options listed d. Q-Cyt C oxidoreductase - ANSC 235. Which of the following reactions occur in Complex 3? a. Oxidation of NADH b. Oxidation of FADH2 c. Oxidation of Q and reduction of Cyt C d. Reduction of Cyt C and oxidation of QH2 - ANSD 236. In the citric acid cycle, when succinate is converted to Malate, which of the following co-enzymes are used? a. NAD+ b. FAD - ANSB 237. Which of the following is the action of myokinase? a. ATP + AMP => 2ADP b. ATP + ADP => 2ADP - ANSA 238. IN which of the following complexes (or enzyme complexes) is the Q (Ubiquinone or Co-Q) reduced? a. Complex 1 and 2 b. None of the options listed c. Complex 1,2,3 and 4 d. Complex 1,2, and 3 - ANSA 239. Which of the following statements is false? a. Peroxidases hydrolyzes H2O2 into H2O b. Dehydrogenases uses atmospheric oxygen for oxidation reacions c. Catalase hydrolyzes H2O2 to O2 and H2O d. Oxidases uses atmospheric oxygen for oxidation reactions - ANSB 240. Cytochrome P450 is classified as a ___________. a. Monooxygenase b. Dioxygenase - ANSA 241. Which of the following reactions occur in Complex 4? a. Reduction of H2O b. Oxidation of O

c. Reduction of O2 d. Reduction of CytC - ANSC 242. In an ATP molecule, the heterocyclic base is not made from which of the following amino acid (or which of the following amino acids do not take part in the biosynthesis of a purine molecule)? a. Asp b. Gln c. Asn d. Gly - ANSC 243. Oligomycin inhibits which of the following reactions? a. ADP to ATP b. ATP to ADP - ANSA 244. Complex 2 refers to which of the following enzyme system? a. Q-Cyt C oxidoreductase b. NADH-Q oxidoreductase c. Cyt C oxidase d. None of the options listed - ANSD 244. In the citric acid cycle, when Malate is oxidized to Oxaloacetate, which of the following co-enzymes is used? a. FAD b. NAD+ - ANSB 245. Cytochrome P450 is classified as a ________________ a. Monooxygenase b. Dioxygenase - ANSA 246. Oligomycin inhibits which of the following reactions? a. ADP to ATP b. ATP to ADP - ANSA 247. Complex II refers to which of the following enzyme systems? a. Cyt C oxidase b. Q-Cyt C oxidoreductase c. None of the options listed d. NADH-Q oxidoreductase - ANSC 248. Which of the following is the greatest quantitative source of the phosphate group? a. Citric Acid Cycle b. Oxidative Phosphorylation c. Phosphagens d. Glycolysis - ANSB 249. Which of the following reactions occur in Complex IV? a. Oxidation of O2 b. Reduction of H2O c. Reduction of Cyt C d. Reduction of O2 - ANSD 250. Which of the following reactions occur in Complex III? a. Reduction of Cyt C and oxidation of QH2 b. Oxidation of NADH c. Oxidation of Q and reduction of Cyt C d. Oxidation of FADH2 - ANSA 251. Complex I oxidizes which of the following molecules? a. NAD+ b. NADH c. FADH2 d. FAD - ANSB 252. H2S, CO, and Cyanide inhibit which of the following complexes? a. Complex IV b. Complex I c. Complex II d. Complex III - ANSA 253. Which of the following has the highest free energy of hydrolysis? a. PPi b. Creatine Phosphate c. Glucose-6-P d. Phosphoenolpyruvate - ANSD 254. Which of the following conversions occur in Complex II? a. NADH to NAD b. FADH2 to FAD c. Fumarate to Succinate d. Succinate to Fumarate - ANSD 255. In the citric acid cycle, when Succinate is converted to Malate, which of the following coenzymes is used? a. NAD+ b. FAD - ANSB 256. Which of the following statements about ATP is false? a. The ribose sugar is connected to the N-9 carbon of the heterocyclic base b. It contains two phosphoric anhydride groups c. The phosphoric anhydride group is stabilized by the Mg2+ ion d. It contains two phosphate ester groups - ANSD 257. Which of the following is the action of Myokinase? a. ATP + ADP => 2 ADP b. ATP +

AMP => 2 ADP - ANSB 258. Assume that the phosphorylation of serine is an endergonic reaction with a value of 8 kJ/mol. To which of the following reactions does it need to couple for the reaction to happen (or proceed)? a. Hydrolysis of Glucose-1-P with a value of -5.0 kJ/mol b. Hydrolysis of Creatine Phosphate with a value of -10.3 kJ/mol c. Hydrolysis of ATP to AMP with a value of -7.7 kJ/mol d. Hydrolysis of ATP to ADP with a value of -7.3 kJ/mol - ANSB 259. Complex I oxidizes which of the following molecules? a. FAD b. FADH2 c. NAD+ d. NADH - ANSD 260. Assume that the phosphorylation of serine is an endergonic reaction with a value of 8 kJ/mol. To which of the following reactions does it need to couple for the reaction to happen (or proceed)? a. Hydrolysis of Glucose-1-P with a value of -5.0 kJ/mol b. Hydrolysis of Creatine Phosphate with a value of -10.3 kJ/mol c. Hydrolysis of ATP to AMP with a value of -7.7 kJ/mol d. Hydrolysis of ATP to ADP with a value of -7.3 kJ/mol - ANSC 261. Which of the following has the highest free energy of hydrolysis? a. Creatine Phosphate b. Phosphoenolpyruvate c. PPi d. Glucose-6-P - ANSB 262. Which of the following reactions occurs in Complex III? a. Reduction of Cyt C and oxidation of QH2 b. Oxidation of FADH2 c. Oxidation of NADH d. Oxidation of Q and reduction of Cyt C - ANSA 263. Which of the following statements is false? a. Glutathione Peroxidase protects erythrocytes against hemolysis by reducing (or converting) H2O2 into H2O b. Reactions of the Pentose Phosphate Pathway (PPP) occur in the cytosol c. The oxidative phase of the Pentose Phosphate Pathway (PPP) generates NADH d. The non-oxidative phase of the Pentose Phosphate Pathway (PPP) generates Ribose-5-P - ANSC 264. Which of the following statements about Acetyl-CoA and gluconeogenesis is true? a. Increased levels of Acetyl-CoA results in inhibition of Pyruvate Carboxylase b. Increased levels of Acetyl-CoA results in activation of Pyruvate Kinase c. Increased levels of Acetyl-CoA results in activation of PDH Kinase d. Increased levels of Acetyl-CoA results in activation of PDH - ANSC 265 Which of the following statements about cAMP is false? a. Higher levels of ATP will result in active Phosphorylase in liver and muscle, being allosterically inhibited b. Epinephrine, Norepinephrine, and Glucagon decrease the activity of Adenylyl Cyclase c. In the muscle, the role of Glycogen is to provide Glucose-6-P for energy needs d. cAMP integrates the regulation of glycogenolysis and gluconeogenesis - ANSB 266. Which of the following statements about Ca2+ (secondary messenger) is false? a.

Increasing Ca2+ increases the activity of Glycogen Synthase b. Increasing Ca2+ increases the activity of Calmodulin-dependent Protein Kinase c. Increasing Ca2+ increases the activity of Phosphorylase Kinase d. Increasing Ca2+ increases the activity of PDH phosphatase - ANSA 267. Which of the following statements is false? (SELECT ALL THAT APPLY) a. 5' AMP integrates the regulation of glycogenolysis as well as glycogenesis b. Glycogen Synthase is made active by phosphorylation c. Protein Phosphatase-1 hydrolyzes the phosphate group from active Glycogen Phosphorylase as well as active Glycogen Synthase d. Glycogen Phosphorylase (or Phosphorylase) is made active by phosphorylation - ANSA, B, AND C 268. Which of the following statements is false? a. Sialic acids are constituents of glycoproteins and gangliosides b. Ganglioside GM1 contains N-acetylneuraminic acid attached to Glucose in the Ceramide-Glc-Gal chain c. Neuraminic acid is derived from Mannosamine and Pyruvate d. Mucoproteins are proteins containing branched or unbranched oligosaccharide chains - ANSB 269. Which of the following statements about inhibition of active phosphorylase is false? a. Glucose inhibits inactive phosphorylase in the muscle b. Glucose inhibits active phosphorylase in the muscle c. ATP inhibits active phosphorylase in the liver d. Glucose-6-P inhibits active phosphorylase in the muscle - ANSA 270. Which of the following statements about control of Glycogen Phosphorylase in muscle is false? a. G6P (Glucose-6-P) activates Phosphorylase b. cAMP activates inactive cAMP-dependent Protein Kinase c. cAMP is deactivated by hydrolysis of the phosphodiester bond d. Phosphorylation of Phosphorylase Kinase activates Phosphorylase Kinase - ANSA 271. Which of the following statements about the well-fed state is false? a. Protein Phosphatase activity increases b. Fructose-1,6-bisphosphate decreases c. Phosphofructokinase-1 (PFK-1) activity increases d. Insulin is released - ANSB 272. Which of the following statements about mono- and disaccharide metabolism is false? a. A student answers Alcohol Dehydrogenase reduces Glyceraldehyde into Glycerol and the student's answer is correct b. A student answers Essential Fructosuria is the deficiency of Fructokinase and the answer is correct c. A student mentions Glycerol-3-P Dehydrogenase is the enzyme that will reduce Dihydroxyacetone Phosphate (DHAP) into Glycerol-3-P d. A student answers Aldolase A can hydrolyze Fructose-1-P into DHAP and Glyceraldehyde-3-P and the student's answer is correct - ANSD 273.

Which of the following statements about Glucagon is false? a. In the muscle, Norepinephrine activates Adenylyl Cyclase b. Muscle is insensitive to Glucagon c. Glucagon secretion from the alpha cells of the pancreas is inhibited by Insulin d. Release of Glucagon results in a decreased shunt of Citrate from the mitochondria into the cytoplasm - ANSD 274. Which of the following statements about Pyruvate is false? a. Pyruvate is converted into Oxaloacetate using Pyruvate Carboxylase b. Pyruvate is converted into Acetyl-CoA using Pyruvate Dehydrogenase c. Pyruvate is converted to aldehyde using Pyruvate Carboxylase d. Pyruvate is converted to Phosphoenolpyruvate using Phosphoenolpyruvate Carboxykinase (PEP-CK) - ANSC

  1. Which of the following statements about the fasting state is false? a. Glucagon is released b. PFK-1 activity decreases c. Bifunctional enzyme PFK-2/FBP-2 is dephosphorylated d. Adenylyl Cyclase activity decreases - ANSC 276. Which of the following statements is false? a. Pyruvate is converted into Oxaloacetate which is then exported into the cytosol to be eventually converted to Glucose b. Hers Disease is caused by a deficiency of the enzyme Liver Phosphorylase c. In gluconeogenesis, G6P is converted to Glucose using Glucose-6-phosphatase d. Lactate can be a substrate for gluconeogenesis - ANSA 277. Which of the following statements about glycogenolysis in the liver is false? a. Increased Ca2+ would result in an increased rate of glycogenolysis b. Release of nonapeptides Vasopressin and Oxytocin increases the rate of glycogenolysis c. Decreased Ca2+ activates Protein Phosphatase and results in Phosphorylation of Phosphorylase Kinase which slows down glycogenolysis d. Glycogenolysis by Phosphorylase produces a monosaccharide with a free anomeric -OH group - ANSD 278. Increased concentration of which of the following molecules inhibits Glycogen Phosphorylase? a. ATP b. Glucose-6-P c. Glucose in the liver d. AMP in the muscles - ANSA 279. Which of the following statements about regulation during fasting is false? a. More ketone bodies are produced in the liver from increased Acetyl-CoA b. Glycogenolysis in the liver is inhibited c. Glucagon is released from the pancreas d. More Glucose is produced in the liver by gluconeogenesis - ANSB 280. Which of the following statements is true? (SELECT ALL THAT APPLY) a. Fructose-1,6-bisphosphatase hydrolyzes Fructose-1,6- bisphosphate b. Glycerol obtained by the lipolysis of Triglycerides enters the Citric Acid Cycle by being converted into DHAP c. PFK-2 synthesizes Fructose-1,6-

bisphosphate d. Phosphoenolpyruvate Carboxykinase converts Oxaloacetate into Phosphoenolpyruvate - ANSA, B AND D 281. NADPH is not used by which of the following processes? a. Cytochrome P450 to introduce an -OH group b. Reductive biosynthesis of macromolecules c. Lipogenesis d. Reduction of Glutathione by Glutathione peroxide - ANSD 282. Which of the following statements is false? (SELECT ALL THAT APPLY) a. The NADH formed in the oxidation of Glyceraldehyde-3- P under aerobic conditions is transported by the Malate shuttle and converted into FADH2 inside the mitochondria b. Inhibition of Pyruvate metabolism leads to lactic acidosis c. PDH Kinase is allosterically activated by high levels of Pyruvate d. Glycolysis is regulated by three enzymes catalyzing nonequilibrium reactions: hexokinase, phosphofructokinase, and pyruvate kinase - ANSA AND C 283. Which of the following statements is false? a. Citrate lyase is activated by high levels of Citrate and converts Citrate in the cytosol into Oxaloacetate and Acetyl-CoA b. Glutamate can be converted into alpha-ketoglutarate and both of these molecules are part of the Malate shuttle used to transport reducing equivalents of NADH from the cytosol into the mitochondria c. Tissues in which gluconeogenesis occurs contain two isoenzymes of succinate thiokinase, one specific for ADP and one for GDP d. Decarboxylation of Malate by Malic Enzyme converts Malate into Oxaloacetate - ANSD 284. Which of the following statements about Insulin is false? a. Release of insulin decreases glycogenolysis b. Release of insulin increases lipolysis c. Release of insulin increases uptake of Glucose d. Release of insulin increases synthesis of Glycogen - ANSB 285. Which of the following statements about the regulation of gluconeogenesis during fasting is false? a. Release of Glucagon is increased b. [Fatty acid] increases c. [Acetyl-CoA] decreases in the liver d. Beta-oxidation of fatty acid increases - ANSC 286. Which of the following about Glucagon is true? a. Release of Glucagon increases glycogenesis b. Release of Glucagon decreases glycogenolysis c. Release of Glucagon increases gluconeogenesis d. Release of Glucagon decreases fatty acid oxidation - ANSC 287. Which of the following statements about diseases related to carbohydrate metabolism is false? a. Glucose can be converted into Fructose using Sorbitol as an intermediate in the presence of Sorbitol Dehydrogenase. Low levels of Sorbitol Dehydrogenase in the cells of the retina and lens results in cell-swelling b. Aldolase Reductase converts Glucose into Sorbitol and