Download PASS MOCK EXAM

PASS MOCK EXAM – FOR PRACTICE ONLY –
Course: BIOL/BIOC 2200
Dates and locations of mock exam take-up:
Facilitator: Sumiya Sheikh Abdirashid
th
Monday Dec. 7 6-7:30pm, SA 304
th
Tuesday Dec. 8 1-2:30pm, AP 132
It is most beneficial to you to write this mock midterm UNDER EXAM CONDITIONS. This means:
• Complete the midterm in 2 hour(s).
• Work on your own.
• Keep your notes and textbook closed.
• Attempt every question.
After the time limit, go back over your work with a different colour or on a separate piece of paper and
try to do the questions you are unsure of. Record your ideas in the margins to remind yourself of what
you were thinking when you take it up at PASS.
The purpose of this mock exam is to give you practice answering questions in a timed setting and to
help you to gauge which aspects of the course content you know well and which are in need of further
development and review. Use this mock exam as a learning tool in preparing for the actual exam.
Please note:
•
Come to the PASS session with your mock exam complete. There, you can work with other
students to review your work.
•
Often, there is not enough time to review the entire exam in the PASS session. Decide which
questions you most want to review – the Facilitator may ask students to vote on which
questions they want to discuss.
•
Facilitators do not bring copies of the mock exam to the session. Please print out and complete
the exam before you attend.
• Facilitators do not produce or distribute an answer key for mock exams. Facilitators help
students to work together to compare and assess the answers they have. If you are not able to
attend the PASS session, you can work alone or with others in the class.
Good Luck writing the Mock Exam!!
DISCLAIMER: PASS handouts are designed as a study aid only for use in PASS workshops. Handouts may
contain errors, intentional or otherwise. It is up to the student to verify the information contained within.
1. Which of the following statements about hormone regulation of fatty acid synthesis is TRUE?
a. Glucagon activates downstream protein kinase to stimulate fatty acid synthesis
b. Glucagon activates downstream protein kinase to inhibit fatty acid synthesis
c. Glucagon inactivates downstream protein kinase to stimulate fatty acid synthesis
d. Glucagon inactivates downstream protein kinase to inhibit fatty acid synthesis
2. Which of the following statements best describes the function of Lipase?
a. Hydrolyze triacylglycerols to fatty acids and glycerol
b. Hydrolyze fatty acids to acetyl co-A
c. Hydrolyze glycerol to acetyl co-A
d. Hydrolyze acetyl co-A to form fatty acids
3. Which of the following statements about the rate-limiting step of fatty acid oxidation is TRUE?
a. Carnatine transfers fatty acyl CoA from mitochondrial matrix to cytosol
b. Carnatine transfers CoA-SH from mitochondrial matrix to cytosol
c. Carnatine transfers fatty acyl CoA from cytosol to mitochondrial matrix
d. Carnatine transfers CoA-SH from cytosol to mitochondrial matrix
4. Fatty acid esterification with CoA-SH followed by a series of carbon backbone reactions best
describes which process?
a. Lipid Mobilization
b. Gluconeogenesis
c. Fatty acid synthesis
d. Beta oxidation
5. Which of the following statements about ACC is FALSE?
a. ACC catalyzes the carboxylation of acetyl-CoA to malonyl-CoA
b. ACC is phosphorylated by protein kinase A to promote fatty acid synthesis
c. ACC catalyzes an irreversible reaction
d. Insulin promotes the dephosphorylation of ACC
6. Ketone bodies:
a. Form acetyl-coA and enter the TCA cylce
b. Can not be broken down as an energy source
c. Form intermediates that enter glycolysis to form ATP
d. Have decreased glucose uptake in the presence of insulin
7. Which of the following statements about polysaccharides is FALSE?
a. Amylose is an energy storage polysaccharide with both α(1à4) and α(1à6) glycosidic
linkages
b. Chintin is made up of N-acetylglucosamine monomers
c. Cellulose is a structural polysaccharide with ß(1à4) glycosidic linkages
d. Starch is more branched than glycogen, allowing for a helical formation
8. The most abundant (by weight) macromolecule in biological cell membranes are:
a. Nucleic acids
b. Proteins
c. Lipids
d. Carbohydrates
9. __________ is a glucose epimer at carbon 4
a. Beta-glucose
b. Fructose
c. Manose
d. Galactose
10. Which of the following molecules arises from mutarotation of α-D-Glucose
a. α-D-Manose
b. α-L-Manose
c. ß-D-Glucose
d. ß-L-Glucose
11. Which of the following is the most stable cyclic state
a. Chair conformation
b. Boat conformation
c. Linear molecules
d. None of the above
12. In a sugar with multiple chiral centers, stereochemical (D and L) assignment is determined by
which carbon?
a. The carbonyl carbon
b. The carbon existing outside of the carbon ring
c. The carbon farthest away from the carbonyl carbon
d. None of the above
13. Assuming they have equal affinity for the enzyme, which would be MORE effective: a noncompetitive inhibitor or a competitive inhibitor?
a. Both would have equal effect
b. Noncompetive inhibitor
c. Competitive inhibitor
d. It would depend on enzyme concentration
14. Which of the following it true about the active site of an enzyme?
a. It is rigid and does not change shape
b. It contains amino acids without sidechains
c. It is found at the center of globular enzymes
d. None of the above
15. Which of the following ions is commonly required in reactions involving ATP?
a. Cu 2+
b. Mg 2+
c. Fe 2+
d. Ca 2+
16. An allosteric inhibitor:
a. Increases the rate of substrate binding.
b. Binds and activates the high-affinity state of the enzymes.
c. Binds to the active site.
d. Does not bind to the active site.
17. Reactions are the result of collisions. Which of the following factors does not contribute to the
likelyhood of a reaction taking place?
a. High concentration of reactants
b. High temperature
c. A catalyst
d. None of the above
18. In the lab, a 2D – Polyacrylamide gel is useful in separating proteins. Its 2 dimensions provide
twice the separation power of SDS-PAGE. What are the 2 dimensions by which 2D-PAGE
separates proteins?
a. pI and MW (molecular weight)
b. Number of helices and number of sheats
c. Hydrophobic residues and hydrophilic residues
d. None of the above
19. Which association of structure and property holds true?
a. Tertiary → more than 1 polypeptide
b. Secondary → overall arrangement of α-helices, β-sheats, turns and loops
c. Primary → amino acid sequence
d. Quaternary → local spatial arrangement of residues
20. 16:1cis∆9 refers to a fatty acid that:
a. Has 9 carbons
b. Has two cis double bonds at C1 and C9
c. Has one double bond
d. None of the above
21. Temperature can readily make a cell membrane more solid or more fluid in response to the
temperature. This phenomenon is called:
a. Liquidation
b. Membrane flexibility
c. Phase transition
d. Membrane asymmetry
22. A chemical reaction has a ∆Go’ = -2000 kJ/mol. If this were an enzyme-catalyzed reaction what
can you predict about the kinetics?
a. It will exhibit very rapid kinetics b. It will exhibit very slow kinetics c. The kinetics of the reaction cannot be predicted d. The kinetics depend on the nature of the reactants 23. For an enzyme displaying Michaelis-Menten kinetics, the reaction velocity (as a fraction of Vmax) at
a substrate concentration of [S] = 9 x KM is:
a. 0.1
b. 0.9
c. 1.0
d. none of the above
24. Which of the following is NOT a component seen in glycolipids?
a. Sphingosine
b. Galactose
c. Phosphate
d. Fatty acid tail
25. Which of the following bonds links glycerol backbones to fatty acid tails
a. Phosphodiester
b. Phosphoanhidride
c. Phosphate ether
d. Ester linkage
26. Which of the following is NOT an example of a polar head group found in glycerophospholipids?
a. Chlorine
b. Inositol
c. Serine
d. Choline
27. Transmembrane lipid asymmetry is maintained by:
a. The Na+/K+ ATPase b. G proteins
c. Protein kinase A
d. Phospholipid specific flippase
28. This class of fatty acid are found in blood group antigens:
a. Sphingolipids
b. Cholesterol
c. Phospholipids
d. None of the above
29. Which of the following statements about membranes is FALSE?
a. Composition can vary depending on type of membrane
b. Composition of the inner and outer monolayers is the same
c. Membranes spontaneously self-assemble
d. None of the above
30. Change in the ionic strength of the solution can remove which class of membrane proteins from
the membranes?
a. Integral b. Fatty-acid anchored c. Peripheral
d. All of the above 31. What is meant by the term “fluid mosaic model”?
a. Diffusion of lipid-soluble substances through the lipid bilayer b. Movement of lipids and integral proteins within the lipid bilayer c. Solubility of water in the membrane d. Method of substance transport across the membrane
32. Which of the following statements about cholesterol is FALSE?
a. Buffers fluidity at high temperatures by increasing melting point
b. Buffers fluidity at low temperatures by preventing tail interactions
c. Buffers fluidity at high temperatures by restricting movement of phospholipids
d. None of the above
33. Which of the following is true about biological membranes?
a. The distribution of phospholipids makes the membrane more symmetrical b. Phospholipids favor flip motion rather than lateral motion c. Cholesterol is equally distributed over both sides d. Lipid self-assembly is an enzyme catalyzed process 34. Which class of membrane protein is incorrectly matched?
a. Peripheral à can only be moved with detergent
b. Lipid-anchored à some are G-Protein coupled receptors
c. Integral à typically have α-helices spanning membrane
d. None of the above
35. Which of the following ions is commonly required in reactions involving ATP?
a. Cu2+ b. Mg2+ c. Fe 2+ d. Ca 2+ 36. Kinases and phosphatases:
a. Are enzymes that destroy damaged proteins b. Help turn proteins "on and off" through changes in phosphorylation status c. Sense short poly A tails in mRNA as a signal to degrade the mRNA d. Destroy 2nd messengers, thereby turning off a signal transduction pathway. 37. Which of the following molecules would not readily cross an intact cell membrane by simple
diffusion?
a. Water b. Glucose c. Oxygen d. Fatty acids 38. he Michaelis constant (Km)
a. Can be easily determined using the Scatchard plot. b. Is equal to twice the Vmax. c. Is equal to the substrate concentration at Vmax / 2. d. Is equal to the turnover number 39. n a biochemical reaction, reactants may be converted into products. The extent to which this
occurs spontaneously is expressed as which of the following?
a. ∆G b. Keq c. Temperature d. All of the above 40. A properly folded protein contains which amino acid in its core depth?
a. Lys
b. Gln
c. Thr
d. Val 41. Primary active transport:
a. Is driven by a direct source of energy (e.g. ATP)
b. Is driven by an ion concentration gradient
c. Both a and b
d. None of the above
42. Which of the following statements about the Na+K+ ATPase is FALSE:
a. Uses energy from ATP to pump Na+ into a cell and K+ out of a cell
b. Maintains cell volume and osmotic stability
c. Restores membrane potential in excitable cells
d. Generates heat
43. Which of the following statements about large molecule transport is FALSE:
a. Low-Density Lipoprotein is taken into the cell via receptor mediated endocytosis
b. Phagocytosis is the most common form of endocytosis
c. Pinocytosis takes up proteins and other molecules from ECF
d. Exocytosis is important in the nervous system for signal proliferation
44. Which of the following statements is FALSE:
a. Can function with or without oxygen
b. Can function with oxygen but prefer to function without
c. Autotrophs use CO2 to fulfill their carbon requirement
d. Chemotrophs use energy from oxidation/reduction reactions
45. The term amphibolic refers to:
a. A protein that is both hydrophilic and hydrophobic
b. A molecule that is both acidic and basic
c. A pathway that is both anabolic and catabolic
d. None of the above
46. Which of the following statements about ATP is FALSE?
a. ATP is a currency for free energy in biological systems
b. It is made up of an adenine base and three phosphates
c. ATP wastes little energy during phosphorylation of an intermediate
d. UTP and GTP have lower energies than ATP
47. Thioesters are:
a. Energetically less stable than oxygen esters
b. Found in the center of membrane proteins
c. Used in proliferation of cell signals
d. None of the above
48. Which of the following reaction types is not correctly matched?
a. Oxidation/reduction à electron transfer
b. Lyases à formation of C-C bond
c. Hydrolytic à cleavage of bonds
d. None of the above
49. Insulin regulation of metabolism is an example of:
a. Intrinsic regulation
b. Extrinsic regulation
c. Competitive regulation
d. Feedback inhibition
50. The enzyme that catalyzes the rate-limiting step in glycolysis is
a. Hexokinase b. Citrate synthase c. Phosphofructokinase d. Pyruvate kinase 51. A drug is tested in the laboratory and is found to create holes in both mitochondrial membranes.
Which of the following will be inhibited in the human cell:
a. Glycolysis b. TCA Cycle
c. Oxidative phosphorylation d. B and C
e. All of the above
52. Once glucose enters the cell, its phosphorylation
a.
a. Keeps the glucose from being transported back out of the cell
b. Allows the cell to maintain higher levels of cytosolic glucose
c. Puts glucose into a form for use in cellular respiration
d. Puts glucose into a form to be eventually stored
53. Which molecule is incorrectly matched with the number of carbon atoms it possesses? a. citrate - 6
b. α-ketoglutarate - 5
c. acetyl-CoA - 2
d. malate - 5
54. Glycogen phosphorylase is inhibited by the which allosteric inhibitor
a. AMP
b. ADP
c. glycogen
d. glucose
e. ATP 55. Phosphorylation does NOT play a regulatory role in the reaction catalyzed by:
a. glycogen phosphorylase b. α-ketoglutarate dehydrogenase c. pyruvate dehydrogenase d. pyruvate kinase e. none of the above 56. When the liver converts excess glucose to fatty acids all of the following are true EXCEPT:
a. The control enzyme is acetyl CoA carboxylase b. The enzyme is activated by protein phosphatase c. Protein phosphatase is activated as a result of glucagon binding to liver cells d. The control enzyme converts ATP, CO2, and acetyl CoA into malonyl CoA, ADP, and Pi e. The concentrations of glucagon, epinephrine, or AMP are low because high concentrations
would inhibit the control enzyme 57. Pyruvate, the end product of glycolysis, is converted to __________ in humans and to
__________ in yeast under anaerobic conditions.
a. acetaldehyde and methanol. b. lactic acid and ethanol c. acetic acid and ethanol d. acetyl-CoA and ethanol e. None of the above
58. Which of the following statements best describes the role of NAD+/NADH in glycolysis?
a. NADH is used to produce energy by directly creating the phosphoanhydride bonds
in ATP.+ b. NAD is used to carry electrons. c. NADH is capable of pumping ions during glycolysis. d. NADH is used primarily in substrate-level phosphorylation. e. all of the above 59. Glucose is transported in the bloodstream to cells in all parts of your body. Once glucose reaches
the cell, Which of the following is incorrect:
a. Glucose is transformed into sucrose b. Glucose is catabolized to carbon dioxide and water c. Glucose is converted to lactate d. Glucose is converted to acetyl CoA to make body fat 60. Which of the following enzymes carries out an anaplerotic reaction that produces citric-acid cycle
intermediates?
a. pyruvate dehydrogenase kinase b. malate synthase c. acetate thiokinase d. dihydrolipoamide dehydrogenase e. none of the above 61. n organisms that lack the glyoxylate cycle, can glucose be made from acetyl-CoA?
a. No b. Yes, via the citric-acid cycle and the conversion of oxaloacetate to PEP c. Yes, via the pentose phosphate pathway and the conversion of erythrose- 4-phosphate to
glyceraldehyde-3-phosphate d. Yes, via gluconeogenesis 62. Which of the following is the first committed step of glycolysis?
a. Phosphofructokinase I
b. Hexokinase
c. Phosphoglucomutase
d. Glucose-6-phosphate isomerase
63. Which of the following statements about oxidative phosphorylation is NOT true (Note! The electron
transport chain or electron transfer chain is abbreviated etc.)
a. The movement of electrons down the etc. only happens if protons are pumped out of the
mitochondria b. If the proton gradient is too high, electrons will not move through the etc. c. A proton gradient is formed across the outer mitochondria membrane d. The fee energy of the proton gradient can be used to create high energy bonds 64. Which of the following statements about the electron transport chain is correct?
a. The electron transport chain is made up of a chain of electron carriers with decreasing
electron affinity
b. The electron transport chain is made up of a chain of electron carriers with increasing redox
potential
c. The electron transport chain is made up of a chain of electron carriers with decreasing
oxidising power
d. The electrons transferred from carrier to carrier in the electron transport chain gain energy
65. When glucose is oxidised, which of the following processes produces the most ATP per molecule
a. aerobic respiration
b. lactic acid fermentation
c. anaerobic respiration
d. all produce approximately the same amount of ATP
66. Which enzyme complex in the Citric Acid Cycle requires the cofactors thiamine pyrophosphate,
Lipoic acid, CoA, FAD and NAD+? a. α-ketoglutarate dehydrogenase b. Succiny-CoA synthetase
c. Malate dehydrogenase d. None of the above
67. The pyruvate dehydrogenase complex:
a. is located in the sarcoplasm b. catalyses the conversion of pyruvate to acetyl CoA c. catalyses the conversion of pyruvate to lactate d. catalyses the conversion of lactate to pyruvate e. catalyses the conversion of pyruvate to glucose 68. The purpose of conversion of pyruvate to lactate during anaerobic fermentation of glucose is to
a. produce carbon dioxide b. produce oxygen c. allow for the reoxidation of NADH d. allow the complete oxidation of glucose 69. Which of the following reactions of the Citric Acid Cycle produces CO2?
a. the formation of α-ketoglutarate b. the formation of succinate c. the formation of isocitrate d. the formation of oxaloacetate 70. Regulated metabolic pathways are a. Irreversible
b. Usually regulated at the first step
c. Compartmentalized in eukaryotes
d. All of the above
71. Which of the following is true abut the inner mitochondrial membrane
a. It is invaginated forming cristae
b. It surrounds a space that is more acidic than the cytoplasm
c. It is permeable to charged molecules
d. Surrounds a space that is more acidic than the intramembrane space
72. Choose the list of intermediates in the correct order for the citric acid cycle
a. succinyl-CoA, succinate, a-ketoglutarate, fumarate, Malate
b. α-ketoglutarate, succinyl-CoA, succinate, fumarate, Malate
c. succinate, succinyl-CoA, fumarate, α-ketoglutarate, Malate
d. α -ketoglutarate, succinyl-CoA, succinate, malate, fumarate
73. Which of the following is the central intermediate that links several carbohydrate metabolic
pathways?
a. Glucose b. Glucose-1-phosphate c. Glucose-6-phosphate d. UDP-glucose 74. Muscles feel sore and burn after strenuous exercise. What is the best explanation for this?
a. Proteins are being digested to provide energy. b. Carbon dioxide is building up in muscle and changing the pH. c. Without oxygen, pyruvate is being converted to lactic acid. d. ADP is accumulating, which produces a burning sensation. 75. Succinate dehydrogenase is an essential enzyme (E.C. 1.3.5.1) of the electron transport chain in
the mitochondria of mammals. Which of the following reactions is it responsible for?
a. NAD+ + ATP→NADP + ADP b. FADH2 + Q→FAD+ +QH2 c. ATP + NAD+ + H2O → NADPH + ADP + OH- d. Glucose + ATP → Glucose 6-phosphate 76. Which of the following statements about the electron transport chain is NOT correct
a. It is located in the inner mitochondrion membrane b. Cytochrome c accepts electrons from complex II
c. Cytochrome oxidase (complex IV) accepts electrons from Cytochrome c d. Coenzyme Q accepts electrons from complex I and complex II 77. In electron transport, the flow of electrons from NADH does not involve which of the following
respiratory complex
a. complex I b. complex II c. complex III d. complex IV 78. In the electron transport chain the final electron acceptor is
a. a molecule of water
b. a molecule of carbon dioxide
c. ATP
d. an oxygen atom
79. Oxidation in biological systems is usually accompanied by:
a. repulsion b. dehydrogenation c. resonance stabilization d. all of the above 80. The conversion of pyruvate to lactate by lactate dehydrogenase (LDH) is accompanied by the
consumption of:
a. ATP
b. ADP
c. NADH
d. NAD+
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