Download biochemistry, cell and molecular biology test

BIOCHEMISTRY, CELL AND MOLECULAR BIOLOGY TEST
Time—170 minutes
180 Questions
Directions: Each of the questions or incomplete statements below is followed by five suggested answers or
completions. Select the one that is best in each case and then completely fill in the corresponding space on the
answer sheet.
1.
Regulation of metabolic pathways includes all
of the following except:
a. Regulation of key enzymes in a pathway.
b. Control transcription and translation to
regulate enzyme amounts.
c. Tissue-specific enzymes and receptors.
d. Reciprocal synthetic and degradative
pathways utilize the same set of enzymes.
e. Compartmentation of reciprocal synthetic
and degradative pathways.
5.
2.
Which of the following statements concerning
cell adhesion complexes is INCORRECT?
a. Tight junctions are a type of
communicating junction.
b. Adherens junctions are a type of
anchoring junction.
c. Selectins form anchoring junctions.
d. Claudins are a component of tight
junctions.
e. Connexons are a component of gap
junctions.
6.
3.
Which of the following statements concerning
homeotic (Hox) genes is INCORRECT?
a. A Hox gene taken from one organism can
function in another organism.
b. The order of Hox gene expression along
the embryo matches the order of Hox
genes on the chromosome.
c. Mutations in Hox genes can create flies
with legs where their antennae should be.
d. Hox genes encode cell surface receptors.
e. Antennapedia is a Hox gene.
a.
b.
c.
d.
e.
In the diagram below, the plane drawn
behind the peptide bond indicates the:
a.
plane of rotation around the Cα—N bond.
b.
absence of rotation around the C—N
bond because of its partial double bond
character.
region of steric hindrance determined by
the large C¬O group.
theoretical space between –180° and
c.
d.
4.
Meiosis can occur
a. in all organisms
b. only when an organism is diploid
c. only in multicellular organisms
d. only in haploid organisms
e. only in single-celled organisms
At the isoelectric pH of a tetrapeptide:
the amino and carboxyl termini are not
charged.
two internal amino acids of the
tetrapeptide cannot have ionizable R
groups.
the total net charge is zero.
there are four ionic charges.
only the amino and carboxyl termini
contribute charge.
e.
angles in the peptide bond.
region of the peptide bond that
contributes to a Ramachandran plot.
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7.
Which of the following situations would result
in an increase in ketone body synthesis?
a. High insulin/glucagon ratio
b. High citrate levels in the cytosol
c. High levels of fructose-2,6-bisphosphate
d. Low oxaloacetate levels in the
mitochondria
e. Low acetyl CoA levels in the mitochondria
10. The pyruvate dehydrogenase complex is
INCORRECTLY described by which of the
following?
a. Produces CO , NADH and acetyl Coenzyme
2
b.
c.
d.
8.
Which of the following statements concerning
tumor suppressor genes is most accurate?
a. In a normal individual, mutation of one
copy of a tumor suppressor gene leads to
cancer.
b. In a normal individual, the development of
cancer requires mutation of one copy of a
tumor suppressor gene in one cell plus the
mutation of the other copy of the gene in
another cell.
c. In a normal individual, the development of
cancer requires mutation of one copy of a
tumour suppressor gene plus the
mutation of the other copy of the gene in
the same cell.
d. In a normal individual, the development of
cancer requires mutation of one copy of a
tumor suppressor gene in one cell plus the
mutation of the same copy of the gene in
another cell.
e. Mutations in tumor suppressor genes are
not passed onto the offspring because the
individual dies.
9.
e.
A
Is phosphorylated in the presence of
insulin
Requires thiamine pyrophosphate to carry
carbons
Can be directly inhibited by NADH and
Acetyl Coenzyme A
Is a target for arsenic poisoning
11. In 1928, Griffith injected S (smooth) bacteria
into mice, and the mice died. When he
injected living R (rough) bacteria into mice, the
mice lived. When he injected heat-killed
smooth bacteria into mice, the mice lived.
What was the result when he mixed heatkilled S bacteria with live R bacteria and
injected this mixture into mice?
a. a. the mice lived
b. b. the mice died indicating that heat-killed
S bacteria came back to life
c. c. the mice lived, and living S bacteria
could be obtained from the tissues of
living mice
d. d. the mice died, indicating that DNA
replicated semi-conservatively
e. e. the mice died, and living S cells could be
isolated from the tissues of the dead mice
12. The regulation of cholesterol synthesis
involves all of the following EXCEPT:
a. glucagon activates HMG-CoA reductase
b. cholesterol inhibits the synthesis of HMGCoA reductase
c. cholesterol increases the degradation of
HMG-CoA reductase
d. the dephosphorylated form of HMG-CoA
reductase is active
e. cholesterol inhibits the synthesis of the
LDL receptor
Given the following reactions:
o
What is the ΔG ’ value for the reaction:
FADH2+½ O2FAD +H2O
o
(ΔG ’ = -nFΔEo’, where F = faraday’s constant=23
-
kcal/volt mole e )
a.
b.
c.
d.
e.
13. At the end of meiosis I, each chromosome
consist of
a. a homologous chromosome pair
b. four copies of a DNA molecule
c. one copy of a DNA molecule
d. two chromatids
e. a pair of polar microtubules
+46 kcal/mol
-46 kcal/mol
+23 kcal/mol
-23 kcal/mol
-11.5 kcal/mol
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14. Which of the molecules shown below can be
made directly from pyruvate?
a.
b.
c.
d.
e.
17. Individual cell migration is most accurately
described by which of the following sequence
of events?
a. (1) Actin polymerization extends from
focal contacts in the direction of
migration; (2) New focal contacts are
made and the treadmilling actin network
engages them to continue the cell
extension; (3) Actin depolymerization at
the minus end of the treadmilling network
detaches the cell from focal contacts at
the rear.
b. (1) Actin polymerization extends from
focal contacts in the direction of
migration; (2) New focal contacts are
made and the treadmilling actin network
engages them to continue the cell
extension; (3) Myosin II contraction
detaches the cell from focal contacts at
the rear.
c. (1) Actin polymerization extends the cell
forward in the direction of migration; (2)
Focal contacts are disassembled at the
front of the cell to allow it to move over
the substratum (3) Myosin II contraction
also detaches the cell from focal contacts
at the rear.
d. (1) Actin polymerization extends the cell
forward in the direction of migration; (2)
Focal contacts are disassembled at the
front of the cell to allow it to move over
the substratum; (3) Actin
depolymerization at the minus end of the
treadmilling network also detaches the
cell from focal contacts at the rear.
e. (1) Individual actin filaments are stabilized
by actin binding proteins; (2) Myosin II
thick filaments move the actin filament
past one another to extend the actin
filament system forward; (3) As the actin
filaments slide forward they engage focal
contacts to pull the rest of the cell
forward.
Molecules 1 and 4
Molecules 2 and 3
Molecules 1, 2, and 4
Molecules 1, 3, and 4
Molecules 1, 2, 3, and 4
15. A patient is taking a drug that must be
activated by cytochrome p450 enzymes to be
fully efficacious. A mutation that inactivates
which of the following enzymes would most
directly affect the patient’s ability to respond
to this medication?
a. A. pyruvate carboxylase
b. B. glucose 6-phosphate dehydrogenase
c. C. pyruvate kinase
d. D. malate dehydrogenase
e. E. citrate synthase
16. A mutation in the lac operator sequence
prevents the lac repressor from binding. What
would you expect to see in bacteria
harbouring this mutation?
a. The bacteria would have difficulty growing
in media containing only lactose.
b. In the presence of glucose and lactose,
the polycistronic message for the lac
operon would accumulate to its maximum
level.
c. The catabolite activator protein would no
longer be able to bind.
d. cAMP levels would be constitutively high.
e. When both glucose and lactose are
absent, lac permease activity would be
higher in the mutant than in normal
bacteria.
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18. Which of the following statements do NOT
account for the differences in complexity
between eukaryotic transcriptional regulation
and bacterial transcriptional regulation?
20. Which of the following oligonucleotides will
dissociate at the lowest temperature?
a. ACGTACGTACGT
TGCATGCATGCA
b. TGCGACGCTGAG
ACGCTGCGACTC
c. ACTGCTGGACCT
TGACGACCTGGA
d. TGCATGCATGCA
ACGTACGTACGT
e. AATGCTTACTGTA
TTACGAATGACAT
i. Eukaryotic DNA is packaged into chromatin.
ii. Eukaryotic RNA Polymerase II cannot activate
transcription on its own.
iii. Eukaryotic Shine-Dalgarno sequences generate
complex patterns of transcriptional regulation.
iv. Eukaryotic gene regulatory proteins act at a
distance.
v. Eukaryotic gene regulatory proteins are not
regulated by ligand binding.
a.
b.
c.
d.
e.
21. In the presence of high glucagon levels, what is
the status of glycogen phosphorylase?
a. Is phosphorylated, active, and sensitive to
glucose 6-phosphate levels
b. Is unphosphorylated, active, and sensitive
to glucose 6-phosphate levels
c. Is phosphorylated, inactive, and sensitive
to glucose 6-phosphate
d. Is phosphorylated, active, and sensitive to
glucose levels
e. Is unphosphorylated, inactive, and
sensitive to glucose levels
i, ii, iii
ii, iv
iii, v
i, ii, iv
ii
19. In an experiment that attempts to identify
origins of replication in yeast, randomly
selected DNA fragments are introduced into a
plasmid that has a selectable marker such as
the HIS gene (histidine). Yeast that have
plasmids with various DNA fragments
introduced are then plated on a selective
medium (i.e. without histidine). What would
be expected in these experiments?
a. Yeast cells that have plasmids with DNA
fragments without putative origins of
replication should grow on media without
histidine.
b. The strain of yeast used for these
experiments should be able to grow in the
absence of histidine.
c. In order to replicate, the plasmids used for
these experiments do not need a DNA
fragment containing an origin of
replication.
d. Yeast cells that have integrated the
plasmid into their chromosome will be
able to grow on media without histidine,
regardless of whether they have a
putative origin of replication or not.
e. Yeast cells must be plated on medium
with histidine to determine if they have
plasmids with DNA fragments containing
putative origins of replication.
22. The cadherin-cadherin binding mechanism is
most accurately described by which of the
following sequence of events?
a. (1) cis-dimerization promotes receptor
straightening; (2) calcium promotes
heterophilic, trans-interactions between
the receptors; (3) the receptors interact
with actin.
b. (1) cis-dimerization promotes receptor
straightening; (2) calcium promotes
homophilic, trans-interactions between
the receptors; (3) the receptors form large
clusters.
c. (1) Calcium promotes receptor
straightening; (2) cis-dimerization
promotes homophilic, trans-interactions
between the receptors; (3) the receptors
form large clusters.
d. (1) Calcium promotes receptor
straightening; (2) cis-dimerization
promotes heterophilic, trans-interactions
between the receptors; (3) the receptors
form large clusters.
e. (1) trans-interactions between the
receptors promote cis-dimerization; (2)
calcium promotes receptor clustering; (3)
the receptors interact with actin.
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23. Assuming Hardy-Weinberg equilibrium, the
genoypte frequency of heterozygotes, if the
frequency of the two alleles at the gene being
studied are 0.6 and 0.4, will be:
a. 0.80
b. 0.64
c. 0.48
d. 0.32
e. 0.16
26. Of the 20 standard amino acids, only
___________ is not optically active. The
reason is that its side chain ___________.
a. proline; forms a covalent bond with the
amino group.
b. alanine; is a simple methyl group.
c. glycine; is unbranched.
d. alanine; contains only hydrogen.
e. glycine; is a hydrogen atom.
27.
A hydronium ion:
is a hydrated proton.
is a hydrated hydrogen ion
c. has the structure H3O+.
d. is the usual form of one of the
dissociation products of water in solution.
e. All of the above are true.
a.
b.
24. One of the reasons for glycosylation of
proteins is to serve as a tag for unfolded
proteins in the endoplasmic reticulum (ER).
What is the role of glycosyl transferase in this
process?
a. It removes the 3 glucose residues that are
found at the end of N-linked
oligosaccharides.
b. It is embedded in the membrane of the ER
and binds to unfolded proteins, thereby
preventing them from aggregating.
c. It binds to unfolded proteins in the lumen
of the ER and adds glucose molecules,
which then bind to calnexin.
d. It is the enzyme that adds a large
preformed oligosaccharide onto
asparagine residues in proteins.
e. It glycosylates calnexin and calreticulin
allowing them to interact and help to
properly fold proteins that are unfolded.
28. The gene coding for a soluble protein that is
normally targeted to the lumen of
peroxisomes is mutated so that an ER signal
sequence is added to the encoded protein at
the N-terminal end. The normal peroxisomal
signalling sequence remains in the encoded
protein. What is the most likely final
destination of the protein?
a. Lysosomes.
b. The nucleus.
c. The protein would be secreted from the
cell.
d. Peroxisomes.
e. The Golgi apparatus.
25. You have digested a plasmid with EcoRI and
expect to obtain fragments 5000 bp, 3000 bp,
and 2000 bp in length. You want to clone the
2000 bp fragment into another vector and to
be able to do this you need to obtain 1 μg of
the desired 2000 bp fragment. Given that you
will be using plasmid DNA at a concentration
of 0.5 μg/μl, how many μl of plasmid DNA
should you add to your EcoRI digest?
a. 2 μl
b. 5 μl
c. 10 μl
d. 4 μl
e. 8 μl
29. What is the function of Ran-GEF?
a. It binds to nucleoporins ensuring that
cargo is transported out of the nucleus.
b. It promotes the exchange of GDP for GTP
on Ran.
c. It binds to the nuclear export signal of the
cargo protein.
d. It transports the empty nuclear export
receptor into the nucleus.
e. It enhances the intrinsic GTPase activity of
Ran.
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30. The preparation of DNA for mitosis is most
accurately described by which set of events?
a. (1) During S phase, the chromatids
assemble kinetochores to interact with
microtubules; (2) During prophase,
condensins compact the chromatids and
cohesins hold the chromatids together; (3)
DNA is then duplicated to form sister
chromatids.
b. (1) During S phase, condensins compact
the chromatids and cohesins hold the
chromatids together; (2) During prophase,
the chromatids assemble kinetochores to
interact with microtubules; (3) DNA is
then duplicated to form sister chromatids.
c. (1) During S phase, DNA is duplicated to
form sister chromatids; (2) During
prophase, cohesins compact the
chromatids and condensins hold the
chromatids together; (3) The chromatids
then assemble kinetochores to interact
with microtubules.
d. (1) During S phase, cohesins compact the
chromatids and condensins hold the
chromatids together; (2) During prophase,
the chromatids assemble kinetochores to
interact with microtubules; (3) DNA is
then duplicated to form sister chromatids.
e. (1) During S phase, DNA is duplicated to
form sister chromatids; (2) During
prophase, condensins compact the
chromatids and cohesins hold the
chromatids together; (3) The chromatids
then assemble kinetochores to interact
with microtubules.
33. One of the in vitro muscle systems required
the addition of calcium ions. What is the
critical role of calcium with respect to muscle
contraction?
a. Calcium is a necessary co-factor for
ATPase activity of the myosin head.
b. Calcium binds to tropomyosin, which
sends a signal to troponin to pull
tropomyosin out of its actin binding
groove.
c. Calcium allows for the proper dynamics of
the large titin protein.
d. Calcium binds to troponin, which releases
tropomyosin into its normal binding
groove so that the myosin heads can bind.
e. Calcium activates calmodulin, which sends
a signal to the troponin complex to pull
tropomyosin out of its actin binding
groove, so the actin can bind to the
myosin heads.
34.
35.
31. Which of the following molecules is a product
of the urea cycle that can be converted back to
a substrate of the urea cycle?
a. aspartate
b. carbamoyl phosphate
c. fumarate
d. malate
e. oxaloacetate
32. The process of fatty acid synthesis involves all
of the following except:
a. A large multi-enzyme complex
b. Acetyl CoA carboxylase
c. NADPH
d. Malonyl CoA
e. CAT I (carnitine acyl transferase I)
In a highly basic solution, pH = 13, the
dominant form of glycine is:
a. NH2—CH2—COOH.
b.
NH3+—CH2—COOH.
c.
NH2—CH2—COO⁻.
d.
NH3+—CH2—COO⁻.
e.
NH2—CH3+—COO⁻.
The single most important contribution to
the stability of a protein's conformation
appears to be the:
a. sum of free energies of formation of
many weak interactions among the
hundreds of amino acids in a protein.
b. entropy increase from the decrease in the
number of ordered water molecules
forming a solvent shell around a protein.
c. sum of free energies of formation of
many weak interactions between a
protein's polar amino acids and
surrounding water.
d. maximum entropy increase from ionic
interactions between the ionized amino
acids in a protein.
e. stabilizing effect of hydrogen bonding in a
protein between the carbonyl group of
one peptide bond and the amino group of
another, as indicated by —C¬O|||H—N—.
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36. Skeletal muscle cells that have a functional
insulin signalling pathway are treated with
insulin. An hour later, a protein extract is
made from the cells. Proteins in the extract
are separated by SDS-PAGE and then the gel is
blotted. The blot is incubated with antibodies
that detect phosphoserine, phosphothreonine
and phosphotyrosine residues in proteins. The
blot is washed and then incubated with an
appropriate secondary antibody to allow for
detection of the primary antibodies. Which of
the following proteins would you expect to
detect on the blot? Give a complete list.
1. insulin receptor
2. IRS-1
3. Grb2
4. Phosphatidylinositol 3-kinase (PI 3-kinase)
5. PDK1
6. protein kinase B (PKB)
a. 2, 3, 4
b. 1, 2, 3, 5, 6
c. 4, 5, 6
d. 1, 2, 5, 6
e. 2, 4
39. What is the correct enzyme name for the
reaction drawn below?
a.
b.
c.
d.
e.
acetoacetate dehydrogenase
β-hydroxybutyrate reductase
β-hydroxybutyrate dehydrogenase
acetoacetate reductase
β-hydroxybutyrate synthase
40. Vitamin deficiencies may affect many
metabolic pathways due to the requirement of
cofactors in enzymatic reactions. The Pentose
Phosphate Pathway (PPP) can be run in one of
four modes, depending on the specific
purpose or product(s) needed (listed below).
Which of these four modes of the PPP would
NOT be affected by thiamine deficiency?
Mode #1: NADPH + Ribose-5-P
Mode #2: NADPH only
Mode #3: NADPH + energy
Mode #4: Ribose 5-P only
37. Which type of regular light microscopy is the
BEST for visualizing transparent internal
structures in living cells?
a. Bright-field microscopy.
b. Transmission electron microscopy.
c. Nomarski Imaging (Differential
Interference Contrast).
d. Fluorescence microscopy.
e. Confocal microscopy.
a.
b.
c.
d.
e.
Mode 1
Mode 2
Mode 3
Mode 4
All modes
41. Which of the following statements concerning
clathrin-coated vesicles is CORRECT?
a. Arf-1 is a GTPase that is needed for the
formation of clathrin-coated vesicles.
b. Clathrin-coated vesicles form in the
membrane of the endoplasmic reticulum.
c. Clathrin-coated vesicles lack V-SNARES.
d. Uncoating of clathrin-coated vesicles
requires a GAP protein.
e. There is a single type of adaptor protein
that interacts with clathrin.
38. Suppose one were provided with an actively
dividing culture of E. coli bacteria to which
radioactive thymine has been added. What
would happen if a cell replicated once in the
presence of this radioactive base?
a. One of the daughter cells but not the
other will have radioactive DNA
b. Neither of the two daughter cells will be
radioactive
c. All four bases of the DNA would be
radioactive
d. Radioactive thymine would pair with nonradioactive guanine
e. DNA in both daughter cells will be
radioactive
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42. New experimental evidence was presented in
class that favours the cisternal model of
protein transport through the Golgi apparatus.
In one experiment, a cis-Golgi resident protein
was labelled with GFP and a trans-Golgi
resident protein was labelled with RFP. Single
cisternae were observed over time with 3D
confocal microscopy. The researchers
observed that greencoloured cisternae
changed into red-coloured cisternae. Why did
the green disappear or the red appear?
a. The red appeared because the RFPlabelled proteins were transported to the
observed cisternae from the medial-Golgi.
b. The green disappeared because the GFPlabelled proteins were transported out of
the observed cisternae in an anterograde
direction.
c. The red appeared because the observed
cisternae fused with the cisternae that
contained the RFP-labelled proteins.
d. The green disappeared because the GFPlabelled proteins were transported out of
the observed cisternae in a retrograde
direction.
e. The green disappeared because the GFPlabelled proteins travelled through the
Golgi and were secreted from the cell.
44. A cell containing 92 chromatids at metaphase
of mitosis would, at its completion, produce
two nuclei each containing how many
chromosomes?
a. 12
b. 23
c. 46
d. 92
e. 184
45. The light reactions of photosynthesis occur in
what structure of the chloroplast?
a. thylakoid membrane
b. chlorophyll molecule
c. stroma of the chloroplast
d. cytoplasm surrounding the chloroplast
e. outer membrane of the chloroplast
46. The molecule shown below can be converted
into which of the following molecules by a
transamination reaction?
a.
b.
c.
d.
e.
43. You are trying to create an artificial
mitochondria with a new category II prosthetic
group to replace cytochrome c. You have
named this new prosthetic group substance X.
Given the standard redox potentials of the two
half reaction:
47. Which of the following correctly pairs a
pathway with one of its regulated enzymes?
a. TCA cycle: fumarase
b. beta-oxidation of fatty acids: CAT II
c. glycolysis: phosphoglycerate kinase
d. fatty acid synthesis: pyruvate carboxylase
e. urea cycle: carbamoyl phosphate
synthetase I (CPS I)
Substance X+ + 2H+ + 2e-  Substance X Eo’ = 0.25
½O2 + 2H+ + 2e-  H2O Eo’ = 0.75
What is the standard free energy change of
the following reaction?
48. Which of the following enzymes is the
common activator of the pancreatic zymogens
involved in polypeptide breakdown in the
small intestine?
a. Pepsin
b. Carboxypeptidase A
c. Elastase
d. Aminopeptidase
e. Trypsin
Substance X + ½O2  Substance X+ + H2O
(Given ΔGo’ = - n FΔEo’ and F = 23 kcal/volt mol e-)
a.
b.
c.
d.
e.
lactate
acetyl CoA
aspartate
alanine
glutamate
- 46 kcal/mol
– 23 kcal/mol
+ 46 kcal/mol
+ 23 kcal/mol
-11.5 kcal/mol
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The following 2 questions refer to the pathway drawn above. The letters in brackets [ ] represent
additional substrates and products for the reactions indicated.
49. Which of the following statements regarding
the above pathway is CORRECT?
a. Biotin provides the “long arm” of the
complex that carries out these reactions.
b. Reaction 3 is a hydration reaction.
c. The committed step of this pathway
produces the three carbon unit of
molecule B.
d. The enzymes that carry out reactions 2
and 4 are dehydrogenases.
e. Reaction 2 requires NAD+ (molecule [H])
and Reaction 4 requires FAD (molecule
[K]).
50. In a liver cell, molecule F (after it is released)
could be immediately used by that same liver
cell for which of the following pathways:
a. Ketone body synthesis only
b. Triacylglycerol synthesis only
c. Phospholipid synthesis only
d. Triacylglycerol synthesis or phospholipid
synthesis
e. Ketone body synthesis or triacylglycerol
synthesis or phospholipid synthesis
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51. Which statement about microarray
experiments is FALSE?
a. They are based on DNA:DNA hybridization
b. They are based on competitive hybrization
using two different pools of nucleic
acids
c. They used fluorescent labeling
d. They can be used to scan the expression
of many genes simultaneously
e. They can be useful in screening for genetic
diseases
55. 6. A compound has a pKa of 7.4. To 100 mL of
a 1.0 M solution of this compound at pH 8.0 is
added 30 mL of 1.0 M hydrochloric acid. The
resulting solution is pH:
a. 7.58.
b. 7.4. at pH=8.0 A/HA = 4/1 or 80mmols A
/ 20mmols HA
c. 7.22. 30mmols of HCl will convert
30mmols of A to HA
d. 6.8. this gives a final ratio of
50mmols/50mmols. pH=pK
e. 6.53.
56. The chirality of an amino acid results from the
fact that its alpha carbon:
a. is a carboxylic acid.
b. is bonded to four different chemical
groups.
c. is symmetric.
d. is in the L absolute configuration naturally
occurring proteins.
e. has no net charge.
52. What is the co-transduction frequency for the
A and B genes, from the following dataset?
(Assume that there has been selection for the
A+ form of the A gene).
Genotype
Number
A+B+ C+
10
A+B+ C30
A+ B- C+
20
A+ B- C40
a.
b.
c.
d.
e.
57. Which of the following would you add to a
tube containing bacterial DNA if you wanted
to make many copies of a portion of the 16S
rRNA gene using PCR?
a. dNTPs, lysozyme, buffer with Mg2+, RNA
primers, and water
b. dNTPs, DNA polymerase, buffer with
Mg2+, DNA primers, and water
c. ddNTPs, DNA polymerase, buffer with
Mg2+, DNA primers, and water
d. dNTPs, DNA polymerase, buffer with
Mg2+, RNA primers, and water
e. dNTPs, reverse transcriptase, buffer with
Mg2+, DNA primers, and water
.10
.20
.30
.40
.50
53. Regarding intermediate filaments, which of
the following statements is TRUE?
a. Intermediate filaments composed of one
type of protein are found in all cells.
b. Intermediate filaments are named
“intermediate” because their ability to
withstand force and deformation is
intermediate between that of
microtubules and actin filaments.
c. Keratin and collagen are two types of
intermediate filaments.
d. Some intermediate filaments can interact
with adhesion complexes and others
strengthen the cell nucleus.
e. Intermediate filaments are polarized.
58. What is the BEST way to determine the size of
a particular transcript in a specific cell type?
a. Perform a microarray analysis.
b. Perform a luciferase assay.
c. Perform a Northern blot.
d. Perform a Gel-Mobility Shift Assay (or
EMSA)
e. Perform a Chromatin
Immunoprecipitation assay.
54. Which of the following molecules is a major
link between the extracellular matrix and
integrins?
a. collagen
b. actin
c. elastin
d. aggrecan
e. laminin
59. Which of the following are primarily
responsible for cytokinesis in plant cells?
a. chromatid condensation
b. Golgi-derived vesicles
c. actin and myosin
d. centrioles and basal bodies
e. cyclin-dependent kinases
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60. The following experiment was performed to examine the unfolded protein response. One group of yeast
cells was treated with a chemical that causes the unfolded protein response, while another group of cells
remained untreated. RNA and protein were isolated from both groups of cells and northern and western
blots were performed. The northern blot was probed with DNA that is complementary to an exon that is
present in RNA coding for a gene regulatory protein that regulates the unfolded protein response. The
western blot was probed with an antibody that is specific for the gene regulatory protein. Which of the
following is the BEST answer for what you would expect to observe?
a.
Sample
Northern
Western
Untreated cells
Band present
No band
Treated cells
Band present same
Band present
weight as untreated
b.
Sample
Northern
Western
Untreated cells
Band present
No band
Treated cells
Band present smaller
Band present
weight than untreated
c.
Sample
Northern
Western
Untreated cells
Band present
No band
Treated cells
Band present larger
Band present
weight than untreated
d.
Sample
Northern
Western
Untreated cells
No band
Band present
Treated cells
Band present
Band present smaller
weight than untreated
e.
Sample
Northern
Western
Untreated cells
No band
No band
Treated cells
Band present
Band present
61. A siRNA from humans was found and
characterised. When the siRNA was introduced
as double-stranded RNA (dsRNA) back into an
undifferentiated human cell line, the cells
differentiated into blood cells. A siRNA with a
different sequence did not have this effect;
cells remained undifferentiated when dsRNA
corresponding to this second siRNA was
introduced into the cell line in an independent
experiment. Together, these results indicate
that:
a. a) the second siRNA is not a good control
for this experiment.
b. the first siRNA activates a gene that is
itself an activator of blood cell
differentiation.
c. the first siRNA represses a gene that is
itself a repressor of blood cell
differentiation.
d. the second siRNA competes with the first
siRNA to regulate blood cell
differentiation.
e. the RISC is not involved in the recognition
of the second siRNA to cause DNA
methylation.
62. Which of the following statements
CORRECTLY completes the following phrase?
During the process of ubiquitination
(ubiquitylation),
a. the carboxy terminus of ubiquitin is
initially activated through a high-energy
thioester linkage to a cysteine side chain
of the ubiquitin activating enzyme, E1.
b. E1 and E2 proteins together form the
ubiquitin ligase complex that binds to a
degradation signal on the target protein.
c. the amino terminus of ubiquitin is initially
activated through a high-energy thioester
linkage to a cysteine side chain of the
ubiquitin activating enzyme, E1.
d. E2 and E3 proteins together form the
ubiquitin activating enzyme that transfers
ubiquitin to E1 ligase before E1 ligase
binds to the degradation signal on the
target protein.
e. the carboxy terminus of ubiquitin is
initially activated through a high-energy
thioester linkage to a cysteine side chain
of the ubiquitin activating enzyme, E3.
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63. In the yeast two-hybrid assay, what is the
role of the GAL4 gene?
a. The GAL4 gene provides the upstream
activating sequences that allow the
expression of the LEU gene when the
“bait” and “prey” fusion proteins have
interacted.
b. The GAL4 gene is included on the bait
plasmid as a selectable marker, as the
yeast strain that is used is gal-.
c. The GAL4 gene provides the coding
sequences for the GAL4 protein
DNAbinding domain that comprise part of
the “bait” fusion protein, and the coding
sequences for the GAL4 protein
transcriptional activation domain that
comprise part of the “prey” fusion
protein.
d. The GAL4 gene encodes an enzyme that is
a reporter that indicates when the “bait”
and “prey” fusion proteins have
interacted and activated transcription.
e. The GAL4 gene is used to indicate the
extent of transformation efficiency when
the yeast strain has been transformed
with the bait plasmid.
66. How would you best describe the caspase
signaling pathway?
a. An inverted pyramid in which many
separate signals at the top converge to
elicit one final molecular effect.
b. A single pathway in which a signal at the
top elicits one final molecular effect in the
nucleus.
c. A single pathway in which a signal at the
top elicits one final molecular effect in the
mitochondria.
d. A normal pyramid in which one initial
signal at the top can elicit many separate
molecular effects.
e. A disorderly pathway associated with
necrosis.
67. DNA polymerase III moves in which direction
along the DNA?
a. 3´ → 5´ along the template strand
b. 3´ → 5´ along the coding (sense) strand
c. 5´ → 3´ along the template strand
d. 3´ → 5´ along the coding strand
e. 5´ → 3´ along the double-stranded DNA
68. Which of the following statements concerning
the mitotic spindle is INCORRECT?
a. Astral microtubules extend towards the
plasma membrane.
b. Overlapping microtubules pull the
centrosomes together.
c. Kinetochore microtubules form between
centrosomes and centromeres.
d. The movement of chromosomes involves
microtubule disassembly.
e. A functional spindle involves both plusand minus-end directed microtubule
motor proteins.
64. Ribosomal RNA is transcribed from multiple
copies of a specific operon in prokaryotes.
Which of the following is the CORRECT order
in descending size of the transcripts from that
operon (from largest to smallest):
a. 16S rRNA 23S rRNA 5S rRNA tRNA
b. 23S rRNA 16S rRNA mRNA 5S rRNA tRNA
c. 23S rRNA 16S rRNA 5S rRNA tRNA
d. 16S rRNA 23S rRNA mRNA 5S rRNA tRNA
e. tRNA 16S rRNA 23S rRNA mRNA 5S rRNA
65. Suppose that an exceptional girl is born who
has three copies of chromosome 22, and she
survives to early adulthood. Which of the
following characteristics would you NOT
expect to find in this woman?
a. Lower than average fertility
b. Health problems involving multiple organ
systems
c. Uneven pairing of some chromosomes
during meiosis
d. Two Barr bodies per cell
e. Production of some unbalanced gametes
(eggs)
69. Which of the following statements about
excision repair is incorrect?
a. Excision repair is always initiated by
specific enzymes that recognize damaged
DNA.
b. Excision repair removes a region of DNA
that extends beyond the damaged
bases on either side.
c. The gap resulting from an excision must
be filled in by special repair enzymes
(e.g. endonucleases).
d. Excision repairs all require an undamaged
template strand.
e. Excision repair usually results in a
perfectly restored DNA helix.
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70. The pathways of protein degradation involve
all of the following except:
a. The lysosomal pathway primarily degrades
proteins from endocytosis.
b. The attachment of ubiquitin to proteins
requires ATP.
c. The proteasome degrades ubiquinated
proteins.
d. Only one molecule of ubiquitin is attached
to a protein to be degraded.
e. The lysosomal pathway uses a variety of
proteases to degrade proteins.
74. Mitochondrial DNA is advantageous for
evolutionary studies because:
a. it is inherited only through the female
parent and thus evolves in a way that
allows trees of relationship to be easily
constructed
b. it is inserted into the X chromosome
c. it first appeared in humans and is not
found in other animals
d. it evolves more slowly than the genes in
the nucleus
e. it was derived from the globin genes as an
extra copy
71. What are the products of beta-oxidation of a
C14 fatty acid?
a. 1 propionyl CoA, 6 acetyl CoA, 6 FADH2,
and 6 (NADH + H+)
b. 8 acetyl CoA, 7 FADH2, 7 (NADH + H+)
c. 6 acetyl CoA, 5 FADH2, 5 (NADH + H+)
d. 7 acetyl CoA, 7 FADH2, 7 (NADH + H+)
e. 7 acetyl CoA, 6 FADH2, 6 (NADH + H+)
75. You would like to determine how a specific
membrane protein is anchored to the plasma
membrane. You express a fusion protein in
cells in which the protein of interest is fused to
GFP. As expected, most of the fluorescence is
localized to the plasma membrane. You then
add phospholipase C to the medium bathing
the cells. The fluorescence disappears from
the membrane. What can you conclude?
a. The protein is anchored via its
transmembrane region, which is
composed of amino acids.
b. The protein is a peripheral protein.
c. The protein is anchored via a prenyl
anchor.
d. The protein is anchored via a
glycosylphosphatidylinositol anchor.
e. The protein is anchored via a fatty acid
chain.
72. What is the correct sequence of enzymes for
the four repeated steps of β- oxidation of
fatty acids?
a. carnitine acyl transferase I (CAT I),
carnitine acyl transferase II (CAT II), βhydroxyacyl-CoA, β-ketothiolase
b. acyl CoA dehydrogenase, enoyl CoA
dehydratase, β-hydroxyacyl CoA
dehydrogenase, β-ketothiolase
c. β-ketoacyl ACP synthase, β-ketoacyl ACP
reductase, β-hydroxyacyl ACP
dehydratase, enoyl ACP reductase
d. acyl CoA dehydrogenase, enoyl CoA
hydratase, β-hydroxyacyl CoA
dehydrogenase, β-ketothiolase
e. acyl CoA reductase, enoyl CoA hydratase,
β-hydroxyacyl CoA reductase, βketothiolase
76. Complex V (ATP synthase) is most accurately
described by which of the following?
a.
b.
c.
73. If the frequency of males affected with an Xlinked recessive condition in a human
population is .10 (one in ten), what will be the
expected frequency of affected females?
a. 0.0001
b. 0.001
c. 0.02
d. 0.01
e. 0.05
d.
e.
+
Requires NAD to transfer protons across
membrane
Is comprised of two portions, one to allow
proton flow and one to synthesize ATP
Produced ATP is released directly into the
cytoplasm
Antimycin inhibits Complex V by stopping
the flow of protons
Its inhibition has no effect on
mitochondrial oxygen consumption
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77.
In the Watson-Crick model of DNA structure
(B-form DNA):
a. the 5' ends of both strands are at one end
of the helix, and both 3' ends are at the
other end of the helix.
b. the bases occupy the interior of the helix.
c. a purine in one strand always hydrogen
bonds with a purine in the other strand.
d. G–C pairs share two hydrogen bonds.
e. A–T pairs share three hydrogen bonds.
81. What functional groups are present on this
molecule?
CH2-CH2-CHO
|
OH
a.
b.
c.
d.
e.
78. RFLP analysis is a technique that
a. uses hybridization to detect specific DNA
restriction fragments in genomic DNA
b. is used to determine whether a gene is
transcribed in specific cells
c. measures the transfer frequency of genes
during conjugation
d. is used to detect genetic variation at the
protein level.
e. is used to amplify genes for producing
useful products
hydroxyl and carboxylic acid
hydroxyl and aldehyde
hydroxyl and ketone
ether and aldehyde
hydroxyl and ester
82. Which of the following statements about the
synthesis of double-stranded cDNA in vitro is
TRUE?
a. cDNA is made by the activity of an RNAdependent RNA polymerase.
b. The synthesis of the second strand takes
place after the degradation of the original
RNA template by RNAse H.
c. The enzyme that is used to synthesise the
first strand of the cDNA is derived from
the bacterial virus, bacteriophage lambda.
d. The first strand of the cDNA is primed by a
polyA primer that binds to the 3’ end of
the RNA template.
e. The first strand of the cDNA is primed by a
polyT primer that binds to the 5’ end of
the RNA template.
79. What is the name given to viruses that have
single-stranded RNA that acts as a template
for DNA synthesis in the host cell?
a. retroviruses
b. proviruses
c. bacteriophages
d. prions
e. phages
83. The gene cI of the bacteriophage lambda was
mutated so that its gene product was no
longer able to bind to DNA. What would you
expect?
a. The helix-loop-helix domain of the cro
protein would no longer bind to its target
DNA.
b. The bacteriophage would not be able to
sustain the lytic state.
c. The bacteria would always be in the
lysogenic state.
d. The cI gene would always be turned off by
the cro protein.
e. The cro protein would not be produced.
80. Following the consumption of a high
carbohydrate meal what following group of
enzymes would you expect to be POSITIVELY
regulated?
a. pyruvate dehydrogenase, hexokinase,
phosphofructokinase
b. fructose 1,6-bisphosphatase,
phosphofructokinase, hexokinase
c. phosphoenolpyruvate carboxykinase,
pyruvate kinase, pyruvate carboxylase
d. glycogen phosphorylase, pyruvate
dehydrogenase, glucokinase
e. phosphofructokinase,
phosphoenolpyruvate carboxykinase,
glucokinase
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84. Prosthetic groups in the class of proteins
known as glycoproteins are composed of:
a. lipids.
b. phosphates.
c. carbohydrates.
d. flavin nucleotides.
e. metals (e.g., molybdenum).
89. Which of the following is a step in the model
of Na+/K+ pump action?
a. The pump is not phosphorylated, instead
the hydrolysis of ATP simply provides
energy.
b. In one conformation, 3 Na+ ions bind to
high affinity sites on the extracellular face.
c. Na+ ions dissociate from low affinity sites
on the cytosolic face.
d. Na+ ions and K+ ions are transported
through the pump simultaneously.
e. In one conformation, 2 K+ ions bind to
high affinity sites on the exoplasmic face.
85. In a mixture of the five proteins listed below,
which should elute second in size-exclusion
(gel filtration) chromatography?
a. cytochrome c, Mr = 13,000
b. immunoglobulin G, Mr = 145,000 (next to
largest)
c. ribonuclease A, Mr = 13,700
d. RNA polymerase, Mr = 450,000
e. serum albumin, Mr = 68,500
90. Glucose uniporters are a family of proteins
that transport glucose. Which of the following
concerning these uniporters is CORRECT?
a. GLUT-2 has a high Km indicating that it
has a high affinity for glucose.
b. GLUT-4 is localized to plasma membranes
of fat and muscle cells when insulin levels
are low.
c. GLUT-1 supplies glucose to most cells of
the body independent of insulin
concentrations.
d. GLUT-1 has a low Km indicating that it has
a low affinity for glucose.
e. At low glucose concentrations, the rate of
transport through GLUT-2 is faster than
the rate of transport through GLUT-1.
86. To determine the isoelectric point of a protein,
a gel is first established that:
a. exhibits a stable pH gradient when
ampholytes become distributed in an
electric field.
b. contains a denaturing detergent that can
distribute uniform negative charges over
the protein's surface.
c. relates the unknown protein to a series of
protein markers with known molecular
weights, Mr.
d. is washed with an antibody specific to the
protein of interest.
e. neutralizes all ionic groups on a protein by
titrating them with strong bases.
87.
One hundred mL of 0.1 M NaOH is added to
55 mL of 0.2 M lactic acid. (The pKa of lactic
91. Which of the following ARE features of X
chromosome inactivation?
i. XIST RNA induces heterochromatin formation.
ii. Hyperacetylation of histones associated with the
X chromosome.
iii. DNA methylation of the X chromosome.
iv. Formation of Barr bodies in mammalian males,
ensuring dosage compensation.
v. Seeding of euchromatin formation by the Xinactivation centre.
vi. Translation of XIST RNA into a DNA methylase.
a. i, ii, iv
b. i, ii, iii, v, vi
c. ii, iii, v
d. i, iii
e. ii, iii, vi
acid is 4.1.) The resulting mixture has a pH
close to:
a. 2.
b. 3.
c. 4.
d. 5.
e. 6.
88. Which of the following are all POSITIVE
regulators of fatty acid synthesis?
a. ATP, citrate, glucagon
b. Insulin, citrate, ATP
c. Palmitoyl CoA, AMP, insulin
d. Glucagon, epinephrine, citrate
e. Palmitoyl CoA, AMP, glucagon
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92. The following is a gel showing the results of
manual sequencing. What is the sequence of
the template strand in the 5’ to 3’ direction?
a.
b.
c.
d.
e.
93.
a.
b.
c.
d.
e.
96. Which of the following statements concerning
ATP synthase and the synthesis of ATP is NOT
correct?
a. ATP synthase contains a transmembrane
F0 region through which protons travel.
b. The energy supplied as protons move
down their electrochemical gradient is
converted to mechanical energy.
c. ATP synthases are of ancient origin and
occur in plants, animals and bacteria.
d. ADP and Pi bind to subunits in the F1
region where they are converted to ATP.
e. V-type ATPases pump protons into the
intermembrane space of mitochondria to
generate a gradient that provides the
energy for ATP synthesis.
5’ TCGCAAGCTGA 3’
5’ ACGCTTGCAGT 3’
5’ TCAGTTCGCGA 3’
5’ TCAGCTTGCGA 3’
None of the above
97. Which of the following statements about
glucagon and epinephrine is incorrect?
a. The release of glucagon and epinephrine
both involve a response to low blood
sugar.
b. Muscle is a target tissue for both glucagon
and epinephrine.
c. Epinephrine is derived from tyrosine.
d. Both glucagon and epinephrine bind to Gprotein coupled receptors.
e. Epinephrine inhibits glucose uptake from
the blood in muscle tissue.
In the α-helix the hydrogen bonds:
are perpendicular to the axis of the helix.
occur mainly between electronegative
atoms of the R groups.
occur mainly between electronegative
atoms of the backbone.
occur only between some of the amino
acids of the helix.
occur only near the amino and carboxyl
termini of the helix.
98. The enzyme glyceraldehyde 3-phosphate
dehydrogenase (GAPDH) is involved in the
energy transfer of the glycolytic pathway.
Which of the following statements does NOT
accurately describe GAPDH?
a. Under anaerobic conditions it requires
lactate dehydrogenase to supply NADH
b. Contains a free sulfhydryl necessary to
bind the substrate
c. Produces a high energy intermediate that
is used for substrate level phosphorylation
d. Utilizes inorganic phosphate to produce
1,3-bisphosphoglycerate
e. The substrate glyceraldehyde 3-phosphate
is oxidized to form a high energy thioester
94. Which of the following complexes is most
likely to act as a green light to progress though
a cell cycle check point?
a. non-phosphorylated cyclin E bound to
phosphorylated Cdk2
b. phosphorylated cyclin E bound to nonphosphorylated Cdk2
c. non-phosphorylated cyclin E bound to
non-phosphorylated Cdk2
d. phosphorylated cyclin E bound to
phosphorylated CAK
e. phosphorylated cyclin E bound to nonphosphorylated CAK
95. Which organelle is primarily involved in the
synthesis of phospholipids and steroids?
a. ribosome
b. chloroplast
c. Golgi apparatus
d. smooth endoplasmic reticulum (ER)
e. nuclear envelope
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99.
The compound that consists of ribose linked
by an N-glycosidic bond to N-9 of adenine is:
a. a purine nucleotide.
b. a pyrimidine nucleotide.
c. adenosine.
d. AMP
e. a deoxyribonucleoside.
100.
In B-DNA each deoxyribose is in the C-2'
endo conformation. This means that it is
a. the furanose ring is completely planar
b. the 2' carbon is in the same plane as the
5' carbon
c. the 2' carbon is in the same plane as the
furanose ring oxygen
d. the 2' carbon is on the same side of the
furanose ring as the 5' carbon
e. the 2' carbon is on opposite side of the
furanose ring from the 5' carbon
101.
a.
b.
c.
d.
e.
102.
103. Which of the following statements about
electron microscopy is TRUE?
a. Scanning electron microscopy (SEM) is
generally used to view internal cellular
structures.
b. The wavelength of a beam of electrons is
about 1000 times shorter than that of
visible light.
c. Glass lenses are used to focus the electron
beam.
d. The achievable resolution of electron
microscopy is similar to that of light
microscopy.
e. Transmission electron microscopy (TEM)
can be combined with the metal
shadowing process to view external
cellular structures.
104. Which of the following statements regarding
aminotransferases (a.k.a. transaminases) is
incorrect?
a. High serum levels of alanine
aminotransferase (ALT) may indicate liver
damage.
b. Aminotransferase reactions are
irreversible.
c. Aminotransferases require a co-factor
derived from vitamin B6.
d. The co-factor of the aminotransferase is
attached to the enzyme via a Schiff base.
e. Glutamate is often a product of
aminotransferase reactions.
Which of the following is a mirror repeat?
GGATCC
CCTAGG
GTATCC
CATAGG
GAATCC
CTTAGG
AGGTCC
TCCAGG
CCTTCC
GCAAGG
The three-dimensional conformation of a
protein may be strongly influenced by amino
acid residues that are very far apart in
sequence. This relationship is in contrast to
secondary structure, where the amino acid
residues are:
a. always side by side.
b. generally near each other in sequence.
c. generally on different polypeptide
strands.
d. generally near the polypeptide chain's
amino terminus or carboxyl terminus.
e. restricted to only about seven of the
twenty standard amino acids found in
proteins.
105. Which of the following statements is correct?
a. CTP is used to activate phosphatidate in
phospholipid synthesis.
b. All of the carbons in cholesterol synthesis
come from malonyl CoA.
c. Phospholipases are used in the synthesis
of phospholipids.
d. HMG-CoA synthase catalyzes the
committed step of cholesterol synthesis.
e. Sphingosine is derived from palmitoyl CoA
and glycerol phosphate.
106. The regulation of cholesterol synthesis
involves which of the following:
a. glucagon dephosphorylates HMG-CoA
reductase
b. cholesterol increases the synthesis of
HMG-CoA reductase
c. cholesterol increases the synthesis of the
LDL receptor
d. cholesterol inhibits the activity of HMGCoA reductase
e. cholesterol inhibits the degradation of
HMG-CoA reductase
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107. Lipoprotein particles are able to transport
lipids, which are hydrophobic, through the
blood because
a. they have a hydrophilic surface and a
hydrophobic interior.
b. they contain bile salts to emulsify the
lipids.
c. they attach the triacylglycerols to
albumin.
d. they have a phospholipid bilayer
containing integral membrane proteins.
e. they degrade the lipids to form ketone
bodies.
108. At which oxidation level does biotin, a cofactor
in pyruvate carboxylase and acetyl
CoAcarboxylase, transfer one-carbon units?
a. –CH3
b. –CO2
c. –CH2d. –CH=O
e. =CH-
112. A pure-breeding collie (long-haired dog) is
bred to a pure-breeding pointer (short-haired
dog). The puppies have a variety of
intermediate hair lengths; some are much
shaggier than others. What kind of genetic
effect is this?
a. epistasis
b. pleiotropy
c. pseudoautosomal inheritance
d. variable expressivity
e. incomplete penetrance
113. Which of the following statements regarding
the regulation of beta-oxidation of fatty acids
is correct?
a. Beta-hydroxyacyl CoA dehydrogenase is
activated by high NADH concentrations.
b. Palmitate is an inhibitor of beta-oxidation.
c. Beta-ketothiolase is activated by high
acetyl CoA concentrations.
d. Carnitine acyl transferase I (CAT I) is
inhibited by high malonyl CoA
concentrations.
e. Insulin stimulates the beta-oxidation of
fatty acids.
109. Which two enzymes are used in the catabolism
of all pyrimidine nucleotides?
a. pyruvate carboxylase and acetyl CoA
carboxylase
b. PRPP (5-phosphoribosyl-1-pyrophosphate)
synthetase and PRPP amido transferase
c. 5’-nucleotidase and nucleoside
phosphorylase
d. ribonucleotide reductase and thymidylate
synthase
e. adenine phosphoribosyl transferase and
hypoxanthine-guanine phosphoribosyl
transferase
114.
In a plot of l/V against 1/[S] for an enzymecatalyzed reaction, the presence of a
competitive inhibitor will alter the:
a. Vmax.
b.
c.
d.
e.
intercept on the l/V axis.
intercept on the l/[S] axis.
curvature of the plot.
pK of the plot.
115. Which of the following proteins is NOT a
component seen in the sliding filament
contraction model?
a. Titin
b. Nebulin
c. Cadherin
d. Myosin
e. CapZ
110. A simple transposon:
a. is a DNA segment that codes for an
enzyme for its own insertion into other
DNA sequences
b. is a DNA segment that codes for several
genes, including one for its own insertion
c. is found only in chloroplasts
d. is the kind that never moves around in the
genome
e. codes for the lactose operon
111. A bacterial plasmid is:
a. the same as a transposable element
b. as large as the bacterial chromosome
c. an extrachromosomal piece of DNA
d. never inserted into the bacterial
chromosome
e. a control element for crossing over
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116. Which of the above molecules is the key intermediate (“branch point”) in the pathways
ofphosphosphingolipid and glycolipid synthesis?
a. A) molecule 1
b. B) molecule 2
c. C) molecule 3
d. D) molecule 4
e. E) molecule 5
117. What does NOT happen in a binding site
selection assay between a DNAbinding protein
and DNA?
a. Increasing concentrations of unlabelled
competitor DNA are added to examine the
specificity of the interaction.
b. The process starts by allowing a protein to
interact with a pool of random
oligonucleotides that have been
radioactively labelled.
c. Shifted bands are excised from the gel and
the DNA used as template in a PCR
reaction.
d. Following the final round of selection, the
DNA is cloned into plasmids and the
inserts from many plasmids are
sequenced.
e. The binding site is enriched in each round
of selection, ultimately revealing the
subset of DNA sites that the protein is
most likely to bind
119. Which of the following transporters is
correctly matched with what it transports?
a. Carnitine: fatty acids
b. LDLs: dietary triacylglycerols (TAGs)
c. Citrate: malonyl CoA
d. Albumin: ketone bodies
e. Glycerol-phosphate: protons (H+)
120. Which of the following statements most
accurately describes the processes in the liver
under conditions in which gluconeogenesis
(GNG) is necessary?
a. The consumption of alcohol would inhibit
GNG because of the excess NADH its
breakdown produces
b. Glucose 6-phosphatase activity would be
activated by high intracellular glucose
c. A pyruvate transporter will be active to
bypass the phosphoglycerate kinase step
of glycolysis
d. Excess fructose 1,6-bisphosphate will feed
forward to activate pyruvate kinase
e. Cytosolic
oxaloacetate
would
be
converted to malate
118. After double fertilization occurs in an
angiosperm:
a. the embryo is haploid
b. the endosperm is triploid
c. the embryo is triploid
d. the endosperm is diploid
e. the endosperm is haploid
121. QTL analysis is used to:
a. identify RNA polymerase binding sites
b. map genes in bacterial viruses
c. determine which genes are expressed at a
developmental stage
d. identify chromosome regions associated
with a complex trait in a genetic cross
e. determine the most rapidly-evolving parts
of genes
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122. A person is suffering from a mutation in a key enzyme involved in carbohydrate metabolism. You run a
battery of tests and determine the patient is capable of processing glucose all the way to pyruvate at normal
rates under standard conditions. During times of anaerobic stress, the patient has a decreased glycolytic
capacity. Which of the following mutated enzymes is matched with the metabolite most likely to be found at
abnormally high levels in this patient under anaerobic conditions?
a.
b.
c.
d.
e.
Mutated enzyme
Glyceraldehyde 3-P dehydrogenase
Lactate dehydrogenase
Glyceraldehyde 3-P dehydrogenase
Lactate dehydrogenase
Phosphofructokinase
Metabolite at high concentration
pyruvate
lactate
dihydroxyacetone phosphate
glyceraldehyde 3-phosphate
pyruvate
123. Which of the following groups contains
enzymes all of which are capable of producing
free ammonia (NH4+)?
a. amino acid oxidases, glutaminase,
glutamate dehydrogenase
b. carbamoyl phosphate synthetase I (CPS I),
glutaminase, glutamine synthetase
c. glutaminase, aminotransferases, amino
acid oxidases
d. glutamine synthetase, carbamoyl
phosphate synthetase I (CPS I), glutamate
dehydrogenase
e. glutamate dehydrogenase, amino acid
oxidases, aminotransferases
126. Which of the following statements about
bacterial conjugation is incorrect?
a. F+ cells act as genetic donors.
b. Genes on the F factor encode proteins for
cell-cell contact and the formation of sex
pili.
c. F+ cells convert F- cells into F+ cells.
d. F' cells have especially high rates of
recombination
e. The F factor is transferred as a single
strand.
127. Which of the following does not involve cyclic
AMP?
a. regulation of glycogen synthesis and
breakdown
b. regulation of glycolysis
c. signaling by epinephrine
d. signaling by acetylcholine
e. signaling by glucagon
124. Assume that a particular human cell is
examined under a microscope and it contains
22 autosomic chromosomes and a Y
chromosome. The cell is most likely to be
a. a somatic cell of a male
b. a somatic cell of an individual suffering
from Downs’s syndrome
c. a fertilized egg (a zygote)
d. a somatic cell of a female
e. a sperm
125. Positional cloning refers to:
a. using a selection procedure to clone a
cDNA
b. cloning a portion of a gene using PCR
c. isolating a gene by PCR using primers from
another species
d. isolating a gene from a specific tissue in
which it is being expressed
e. mapping a gene to a chromosomal region
and then identifying and cloning a
genomic copy of the gene from the region
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Directions: Each group of questions below consists of five lettered headings followed by a list of numbered
words, phrases, or sentences. For each numbered word, phrase or sentence, select the one heading that is most
closely related to it and fill in completely the corresponding space on the answer sheet. One heading may be
used once, more than once, or not at all in each group.
Questions 128-132 refer to the following terms:
Questions 137-141 refer to the following terms:
A. GMP
B. UMP
C. ATP
D. dTMP
E. dATP
a. Light dependent reactions
b. Light independent reactions
c. Glycolysis
d. Krebs cycle
e. Electron transport system
128. Inhibits synthesis of PRPP (5-phosphoribosyl-1pyrophosphate) from ribose 5-phosphate
129. Directly stimulates the overall activity of
ribonucleotide reductase
130. 5-fluorouracil is the chemotherapeutic drug
used to target the last enzyme in the synthesis
of this Nucleotide
131. Activates methyl group of methionine
132. Committed step in de novo synthesis of this
nucleoside monophosphate requires PRPP.
137. Make ATP from light.
138. Breakdown glucose into smaller carbon
compounds.
139. Make sugar from CO2.
140. Make ATP and water.
141. Make ATP and split water.
Questions 142-146 refer to the following terms:
a.
b.
c.
d.
e.
Questions 133-136 refer to the following terms:
Match the phrases about gene regulation in
prokaryotes to the terms in the list by putting a
single letter in each blank. Not all letters need to be
used, and a particular letter may be used more
than once.
Centrifugation
Light microscope
Scanning electron microscope
Transmission electron microscope
Paper chromatography
142. Examining the surface of cells.
143. Looking at the internal structure of
chloroplasts.
144. Watching cells with flagella move.
145. Separating pigments of a leaf.
146. Isolating nuclei from cells.
a. Effector molecule
b. Activator
c. Operator
d. Inducible
e. Repressor
133. Small molecule that binds to a regulatory protein to
change its action
134. Binding site for regulatory proteins
135. Regulatory molecule that binds to operator region in
DNA
136. Regulatory protein that promotes transcription
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Directions: Each group of questions below concerns a laboratory or an experimental situation. In each case, first
study the description of the situation. Then choose the one best answer to each question and fill in completely
the corresponding space on the answer sheet.
22
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23
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24
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25
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26
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27
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28
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29
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30
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Worksheet for the Biochemistry Test Only
31
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Answer Key and Percentages* of Examinees Answering Each Question Correctly
Question
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
Answer
D
A
D
B
C
B
D
C
D
B
E
A
D
E
B
E
B
C
D
E
D
C
C
C
C
E
E
C
B
E
C
E
D
C
B
D
C
E
C
A
A
D
B
C
A
D
E
E
C
D
A
D
D
E
B
B
B
C
B
B
Question
Number
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
Answer
C
A
C
C
D
D
A
B
C
D
E
D
D
A
B
B
B
A
A
A
B
B
D
C
B
A
D
B
E
C
D
A
C
A
D
E
B
A
C
D
E
B
E
B
A
D
A
B
C
A
C
D
D
C
C
E
A
C
A
A
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
D
D
A
E
E
D
D
A
C
D
C
A
A
C
E
B
A
C
B
E
A
C
D
B
E
A
D
B
B
B
C
D
B
A
D
C
D
C
C
B
C
D
B
D
E
D
C
C
D
C
D
C
B
B
B
D
B
E
Total correct: _________
Total Incorrect: ________
Score:Question
____________
Number
Answer
32
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