Download bioc-2200-a-biol-2200-a-mock-final-exam

BIOC/BIOL 2200
Gabriela Bernal Astrain
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need of further development and review. Use this mock exam as a learning tool in preparing
for the actual exam.
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Good Luck writing the Mock Exam!!
Dates and locations of mock exam take-up: Thursday December 15th, 2016 4:00pm (ME 3380)
Office Hours: Saturday December 17th, 2016 – 10:00 am – 12:00pm (ML 413)
BIOC/BIOL 2200
Gabriela Bernal Astrain
1. 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
2. Which of the following is the central intermediate that links several carbohydrates metabolic
pathways?
a. Glucose
b. Glucose-1-phosphate
c. Glucose-6-phosphate
d. UDP-glucose
3. Succinate dehydrogenase is an essential enzyme (E.C. 1.3.5.1) of the electron transport chain
inthe 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
4. 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
5. 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
BIOC/BIOL 2200
Gabriela Bernal Astrain
6. 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
7. 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
8. In a newly discovered fungus, am unknown protein is isolated that is localized in the inner
mitochondrial membrane. Upon removal of the protein, the cell appears to be capable of
metabolizing FADH2, however fermentation products begin to accumulate. What is the most
likely identity of this protein?
a. hexokinase
b. pyruvate decarboxylate
c. citrate synthase
d. NADH dehydrogenase
9. Fatty acid catabolism will cause which of the following?
a. increased glycolytic activity
b. decreased phosphofructokinase activity
c. increased utilization of the malate-aspartate shuttle
d. decreased electron transport chain activity
10. Glucagon has what impact on glucose metabolism?
a. increased glycogen synthesis
b. decreased glycogen synthesis
c. increased glucose uptake from the bloodstream
d. decreased gluconeogenesis activity
BIOC/BIOL 2200
Gabriela Bernal Astrain
11. What best describes the active site of an enzyme designed to catalyze a reaction with a
positively charged transition state?
a. hydrophobic amino acids to stabilize the transition state with weak interactions
b. acidic amino acids to stabilize the transition state with electrostatic interactions
c. basic amino acids to stabilize the transition state with electrostatic interactions
d. large variability in the active site.
12. Soap bubbles form because fatty acids:
a. lysosomes
b. phospholipids bilayers
c. micelles
d. hydrogen bonds
13. Which of the following describes the structure of steroids?
a. three cyclopentane rings, one cyclohexane ring
b. four carbon rings, but no real pattern
c. three cyclohexane rings, one cyclopentane ring
d. three cyclic carbon rings and a functional group
14. Why are triglycerols used in the human body for storage?
a. highly hydrated, and can store a lot of energy
b. Carbon atoms on fatty acids are very reduced and therefore yield more energy
c. always have short fatty acid chains for ease of access
d. polysaccharides are the better source of energy
Gabriela Bernal Astrain
BIOC/BIOL 2200
15. What is true about cholesterol?
a. is a steroid precursor
b. interacts only with hydrophobic tails of phospholipids
c. always increases membrane fluidity
d. cholesterol is just horrible for you
16. Which is true about glycerophospholipids?
a. they can sometimes be sphingolipids, depending on the head group
b. have only one glycerol, one polar head, and one fatty acid
c. are used in the ABO blood typing system
d. are a subgroup of phospholipids
17. A large, polar molecule is transported across the energy without ATP- the likely mechanism
is:
a. active transport
b. facilitated diffusion
c. exocytosis
d. endocytosis
18. What is NOT a function of the cell membrane?
a. cytoskeleton attachment
b. transport regulation
c. protein synthesis
d. second messenger reservoir
19. The bulk movement of liquid into a cell is called:
a. phagocytosis
c. pinocytosis
b. exocytosis
d. drinking
Gabriela Bernal Astrain
BIOC/BIOL 2200
20. Which of the following statements conflicts with the fluid mosaic model?
a. cell membranes are static in nature
b. hydrophobic interactions stabilize the membrane
c. membrane components can be derived from many biomolecules
d. proteins are asymmetrically distributed within the membrane
21. Which of the following is a sphingolipid?
a. lecithin
b. cholesterol
c. phosphatidylinositol
d. gangliosides
22. When Beta oxidation predominates in liver, mitochondrial pyruvate is likely to be:
a. carboxylated to phosphoenolpuruvate for gluconeogenesis
b. carboxylated to oxaloacetate for entry into gluconeogenesis
c. oxidatively decarboxylated to acetyl-CoA for [O] in TCA
d. reduced to lactate in the process of fermentation
23. Each of the following catalyzes a rate-limiting step of a carbohydrate metabolism pathway
except:
a. hexokinase
b. G6P dehydrogenase
c. glycogen synthase
d. phosphofructokinase
24. After a large, balanced meal, all of the following should be present except:
a. fatty acids
c. insulin
b. glucagon
d. glucose.
Gabriela Bernal Astrain
BIOC/BIOL 2200
25. After fasting, ________levels should be elevated
a. glycolysis
c. glycogenesis
b. glycogenolysis
d. glycerol synthesis
26. What gluconeogenesis enzyme is correctly linked with the glycolysis enzyme?
a. phosphofructokinase/fructose 1,6 bisphosphatase
b. hexokinase/glucokinase
c. pyruvate dehydrogenase/pyruvate carboxylase
d. pyruvate kinase/ glucose 6 phosphatase
27. When oxygen levels are reduced, which enzyme would be activated by increased levels of
AMP
a. succinate dehydrogenase
b. isocitrate dehydrogenase
c. phosphofructokinase
d. pyruvate dehydrogenase
28. A toxic compound that disrupts the mitochondrial membrane permeability would result in:
a. increased ATP levels
b. increased ATP synthase activity
c. Increase oxygen use
d. decreased pyruvate dehydrogenase activity
29. what process-site is incorrectly matched?
a. glycolysis cytosol
b.ATP phosphorylation cytoskeleton and mitochondria
c. TCA  outer mitochondrial membrane
d. ETC  inner mitochondria membrane
Gabriela Bernal Astrain
BIOC/BIOL 2200
30. Fatty acids can enter the TCA cycle in the form of:
a. glycerol
c. adipose tissue
b. acetyl-CoA
d. ketone bodies
31. Where is cytochrome c located?
a. mitochondrial membrane
b. inner mitochondrial membrane
c. outer mitochondrial membrane
d. cytosol
32. Which reaction results in oxidation?
a. FAD to FADH2
b. NADPH to NADP+
c. NAD+ to NADH
d. ADP to ATP
33. Which of the following provides the energy needed for the ATP synthesis
a. electron transfer ETC
b. oxidation of acetyl-CoA
c. electrochemical proton gradient
d. B-oxidation of fatty acids
34. What amino acid provides the most energy when degraded?
a. glycine
b. valine
c. alanine
d. isoleucine
BIOC/BIOL 2200
Gabriela Bernal Astrain
35. 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.
36. 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
37. 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
38. 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
39. 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
BIOC/BIOL 2200
Gabriela Bernal Astrain
40. 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
41. Ketone bodies:
a. Form acetyl-coA and enter the TCA cycle
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
42. Which of the following is the most stable cyclic state
a. Chair conformation
b. Boat conformation
c. Linear molecules
d. None of the above
43. 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
44. Which of the following statements about polysaccharides is FALSE?
a. Amylose is an energy storage polysaccharide with both α(1a 4) and α(1a 6) glycosidic
linkages
b. Chitin is made up of N-acetylglucosamine monomers
c. Cellulose is a structural polysaccharide with ß(1a 4) glycosidic linkages
d. Starch is more branched than glycogen, allowing for a helical formation
BIOC/BIOL 2200
Gabriela Bernal Astrain
45. Which of the following ions is commonly required in reactions involving ATP?
a. Cu 2+
b. Mg 2+
c. Fe 2+
d. Ca 2+
46. 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.
47. Reactions are the result of collisions. Which of the following factors does not contribute to
the likelihood of a reaction taking place?
a. High concentration of reactants
b. High temperature
c. A catalyst
d. None of the above
48. 16:1cisΔ 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
49. 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
BIOC/BIOL 2200
Gabriela Bernal Astrain
50. 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
51. Which of the following is NOT a component seen in glycolipids?
a. Sphingosine
b. Galactose
c. Phosphate
d. Fatty acid tail
52. Which of the following bonds links glycerol backbones to fatty acid tails
a. Phosphodiester
b. Phosphoanhydride
c. Phosphate ether
d. Ester linkage
53. Which of the following is NOT an example of a polar head group found in
glycerophospholipids?
a. Chlorine
b. Inositol
c. Serine
d. Choline
54. Transmembrane lipid asymmetry is maintained by:
a. The Na+/K+ ATPase
b. G proteins
c. Protein kinase A
d. Phospholipid specific flippase
55. 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
BIOC/BIOL 2200
Gabriela Bernal Astrain
56. 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
57. 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
58. 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
59. Which of the following statements about the role of the pentose phosphate pathway is
correct?
a. it produces ribose-5-phosphate and NADPH
b. oxidizes glucose-6-phosphate completely to CO2 and water
c. the rate-limiting reaction of the pathway is catalyzed by transketolase
d. the pathway occurs in the mitochondria of most cells
60. The pentose phosphate pathway phosphate pathway represents an oxidation/reduction.
The most reduced product of this pathway is
a. CH4
b. ethanol
c. NADPH
d. ATP
Gabriela Bernal Astrain
BIOC/BIOL 2200
61. The pentose phosphate pathway involves:
a. only pentoses
b. pentoses and hexoses only
c. hexoses only
d. trioses, tetroses, pentoses, hexoses, and heptoses
e. only tetroses and pentoses
62. All of the following statements about the pentose phosphate pathway are true EXCEPT
a. Its two functions are to produce NADPH and ribose-5-P
b. It uses glucose-6-P as a substrate when producing NADPH and CO2
c. Glucose-6-phosphate dehydrogenase is the control enzyme and it is regulated by the
NADPH concentration of the cell
d. If it is producing more than twice as much NADPH as ribose-5-P, it can produce
glyceraldehyde-3-P and fructose-6-P
e. It is found in the mitochondria of liver, muscle and brain but is absent from most
other tissues of the body
63. Which of the following types of membrane transporters show saturable kinetics?
a. passive transporters
b. active transporters
c. pores/channels
d. a and b
e. a and c
64. Which of the following metabolic processes is amphibolic?
a. glycolysis
d. glycogen synthesis
b. the TCA cycle
e. All of the above
c. gluconeogenesis
Gabriela Bernal Astrain
BIOC/BIOL 2200
65. How many protons need to transverse the inner mitochondrial membrane to produce one
molecule of ATP in the mitochondrial matrix and deliver it to the cytosol?
a. 1
b. 2
c. 3
d.4
66. Which of the following steps of glycolysis catalyze substrate level phophorylations?
a. phosphoglycerate kinase
b. pyruvate kinase
c. phosphofructokinase-1
d. a and b
e. a and c
67. How many electrons does NADH donate to Complex I of the electron transport chain?
a. 1
b. 2
c. 3
d. 4
d. None
68. Anabolic processes results in the _________.
a. breakdown of complex molecules to produce simple molecules and the generation of
energy
b. synthesis of complex molecules from simple molecules through the consumption of
metabolic energy
c. none of the above
69. Fructose 2,6 bisphosphate is an inhibitor of what enzyme?
a. Pyruvate kinase
b. Aldolase
c. Alpha-ketogluturate dehydrogenase
d. Phosphofructokinase-1
e. Fructose 1,6 bisphosphatase
Gabriela Bernal Astrain
BIOC/BIOL 2200
70. Which of the following classes of acyl-lipids is primarily used as a source of stored energy?
a. phospholipids
b. sphingolpids
c. triacylglycerol
d. cholesterol
e. none of the above
71. An antiport transports ___________________.
a. a single molecule across a membrane.
b. two molecules in the same direction across a membrane.
c. two molecules in the opposite directions across a membrane.
d. None of the above.
72. _______ moles of ATP are produced through glycolysis from one mole of glucose to the
formation of two moles of pyruvate.
a. One
b. Two
c. Three
d. Four
73. Factors influencing the phase transition temperature of a lipid bilayer are _______.
a. the length of the fatty acids attached to the phospholipids.
b. the number of double bonds in the fatty acids attached to the phospholipids.
c. the amount of cholesterol present.
d. All of the above.
e. None of the above.
Gabriela Bernal Astrain
BIOC/BIOL 2200
74. The purpose of the Cori Cycle is to_______________________.
a. regenerate glucose in the liver from ethanol produced in the muscle tissues under
anaerobic conditions.
b. regenerate glucose in the liver from lactic acid produced in the muscle tissues under
anaerobic conditions.
c. regenerate lactic acid in the liver from ethanol produced in the muscle tissues under
anaerobic conditions.
d. regenerate glucose in the liver from galactose produced in the muscle tissues under
anaerobic conditions.
e. None of the above
75. 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.
76. Which of the following molecules would not readily cross an intact cell membrane by simple
diffusion?
a. Water
c. Oxygen
b. Glucose
d. Fatty acids
77. 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
78. In a biochemical reaction, reactants may be converted into products. The extent to which
this occurs spontaneously is expressed as which of the following?
a. ΔG
b. Keq
c. Temperature
d. All of the above
BIOC/BIOL 2200
Gabriela Bernal Astrain
79. A properly folded protein contains which amino acid in its core depth?
a. Lys
b. Gln
c. Thr
d. Val
80. 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
81. 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
82. Which of the following reaction types is not correctly matched?
a. Oxidation/reduction  electron transfer
b. Lyases  formation of C-C bond
c. Hydrolytic  cleavage of bonds
d. None of the above
83. Insulin regulation of metabolism is an example of:
a. Intrinsic regulation
b. Extrinsic regulation
c. Competitive regulation
d. Feedback inhibition
84. An 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- 4phosphate toglyceraldehyde-3-phosphate
d. Yes, via gluconeogenesis
BIOC/BIOL 2200
Gabriela Bernal Astrain
85. 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
86. 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
87. Which of the following describes uncompetitive inhibition?
a. An inhibitor that is a structural analog of the substrate
b. An inhibitor that binds to the enzyme-substrate complex
c. An inhibitor that binds to an allosteric site on the free enzyme
d. None of the above
88. A cofactor is:
a. A component that works with the enzyme to assist in catalysis
b. A molecule derived from a B-vitamin
c. A mechanism affected by factors that can affect rate of enzymatic reactions
d. A region on an enzyme where reactions occur
BIOC/BIOL 2200
Gabriela Bernal Astrain
89. Which of the following statements about protein folding is FALSE?
a. Non-polar amino acids form a molten hydrophobic core
b. Proteins fold via folding landscapes that allow proteins to form the correct 3D
structure
c. The overall free energy change of folding is positive
d. α-helices and β-sheets make up most of the polypeptide backbone than any other
secondary structure
90. Which of the following statements describes the 2nd Law of Thermodynamics?
a. Energy in a closed system is always constant
b. Entropy in the universe is always increasing
c. Energy in an open system is always increasing
d. Entropy in a closed system is constant