BIO 315 Exam I (F2014)

SID#: (w/9)________________________(Also give on last page of exam and on grid sheet)
BIO 315 Exam I (F2014)
Choose A,B, C, or D for each of the following Multiple Choice questions: (2 pt ea)
1) Which of the following properties of an atom affect its electronegativity:
A)
B)
C)
D)
number of electrons in the outer shell
number of protons in the nucleus
distance between the protons of the nucleus and electrons of the outer shell
both B and C x
2) Which of the following is responsible for C being slightly more electronegative than H:
A)
B)
C)
D)
C contains more protons in its nucleus than H. x
C contains fewer protons in its nucleus than H.
The outer shell electrons are closer to the nucleus of C than they are in H.
The outer shell electrons are closer to the nucleus of H than they are in C.
3) Which of the following contribute to C being more oxidized in the C-O bond:
A) O contains more protons in its nucleus than C, and the outer shell electrons of O are also
located closer to its nucleus than those of C.
B) O contains fewer protons in its nucleus than C, and the outer shell electrons of O are also
located closer to its nucleus than those of C.
C) The outer shell electrons are located the same distance from the nucleus in O and C, but
O contains fewer protons in its nucleus than C.
D) The outer shell electrons are located the same distance from the nucleus in O and C, but
O contains more protons in its nucleus than C. x
4) Which atoms of a polypeptide participate in the H bonds stabilizing the β-sheet:
A)
B)
C)
D)
electronegative atoms of polar charged amino acid R groups
electronegative atoms of polar uncharged amino acid R groups
electronegative atoms of nonpolar amino acid R groups
electronegative atoms of the peptide bonds x
5) Which of the following types of microscopy would provide the highest resolution
information about where a specific protein is located within a specific subcellular organelle:
A) electron microscopy
B) immunoelectron microscopy x
C) immunofluorescence
D) fluorescence microscopy of a GFP-tagged version of the protein
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6) Which of the following string of amino acids would you expect to find in the interior of a
properly folded protein:
A)
B)
C)
D)
Asp-Thr-Glu-Tyr-Ser-Lys-Lys
Thr-Ser-Tyr-Phe-Gln-Gln-Phe
Ala-Met-Ile-Leu-Met-Val-Leu x
Cys-Lys-Arg-His-Cys-Lys-Lys
7) Which of the following types of non-covalent bonds/interactions requires a specific pH range
to form:
A) H bond
B) Hydrophobic Interactions
C) Van der Waals Interactions
D) Ionic bond x
8) Use the Table of pK' values for various amino
acids on the right to determine which of the
following amino acids pairs could form an ionic
bond between their R groups at pH 5.0, but not
at pH 7.0.
A)
B)
C)
D)
Lysine and Histidine
Aspartic Acid and Glutamic Acid
Aspartic Acid and Lysine
Aspartic Acid and Histidine x
9) Which of the following conditions is MOST
likely to describe an exergonic reaction:
A) one that produces products with lower bond energies than the reactants and which are
more disordered than the reactants. x
B) one that produces products with lower bond energies than the reactants and which are less
disordered than the reactants
C) one that produces products with higher bond energies than the reactants and which are
more disordered than the reactants
D) one that produces products with higher bond energies than the reactants and which are
less disordered than the reactants
10) Which of the following describes a reaction in which the reactant bonds contain lower
energy than the product bonds and the reactants and products are equally ordered:
A)
B)
C)
D)
ΔH=0 and ΔS<0
ΔH<0 and ΔS<0
ΔH>0 and ΔS=0 x
ΔH>0 and ΔS<0
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11) A reaction with which of the following thermodynamic parameters would be LEAST likely
to occur spontaneously without any external energy:
A) ΔH=0 and ΔS<0
B) ΔH>0 and ΔS<0 x
C) ΔH=0 and ΔS>0
D) ΔH<0 and ΔS=0
12) Use the Table of Standard Redox
Potentials to the right to determine which
of the following electron transfer reactions
would occur spontaneously under
standard conditions:
A)
B)
C)
D)
from lactate to oxaloacetate x
from malate to NAD+
from NADH,H+ to Acetate
from Ubiquinol to fumarate
13) Which of the following electron transfer
reactions would release enough energy to
produce 1 mole ATP under standard
conditions:
A) from malate to NAD+
B) from isocitrate to NAD+
C) from cytochrome b(red) to cytochrome
c(ox) x
D) from cytochrome b(red) to Ubiquinone
14) The reaction shown to the right is the final step in the
TCA cycle. Use the Table of Standard Redox potentials
above and what you learned about thermodynamics and
enzymes to determine which of the following is a correct
statement:
A) The reaction would occur spontaneously under standard conditions, as well as under the
nonstandard conditions of the cell.
B) The reaction would not occur spontaneously under standard conditions, but the enzyme
catalyzing the reaction could alter the thermodynamics and allow it to proceed in the cell.
C) The reaction would not occur spontaneously under standard conditions, but it can occur in
the cell because it is coupled to the strongly exergonic reaction of ATP hydrolysis.
D) The reaction would not occur spontaneously under standard conditions, but it must be
followed by a strongly exergonic reaction that keeps oxaloacetate levels low and allows
the reaction to occur in the cell. x
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15) The X-Ray crystal structures of PrP protein variants that were either resistant, moderately
susceptible, or highly susceptible to forming the PrPsc prion form showed which of the
following:
A) Mutations in the highly susceptible variant optimized H-bonding between neighboring R
groups in a way that stabilized the β-sheet of the PrPsc prion protein.
B) Mutations in the resistant variant caused an ionic repulsion between neighboring R
groups in a way that destabilized the β-sheet of the PrPsc prion protein.
C) Both A and B. x
D) Neither A nor B
16) ATP production in fast twitch (white) muscle fibers is accomplished through which of the
following processes:
A) substrate level phosphorylation through reactions of glycolysis
B) substrate level phosphorylation from creatine phosphate stores
C) oxidative phosphorylation
D) A and B, not C x
17) During starvation, which of the following immediate allosteric effects occur:
A) High AMP inhibits the enzyme catalyzing a highly exergonic reaction of glycolysis and
stimulates the key enzyme bypassing this step in gluconeogenesis.
B) High AMP stimulates the enzyme catalyzing a highly exergonic reaction of glycolysis
and inhibits the key enzyme bypassing this step in gluconeogenesis. X
C) High ATP inhibits the enzyme catalyzing a highly exergonic reaction of glycolysis and
stimulates the key enzyme bypassing this step in gluconeogenesis.
D) High ATP stimulates the enzyme catalyzing a highly exergonic reaction of glycolysis
and inhibits the key enzyme bypassing this step in gluconeogenesis.
18) Which of the following is a true statement about how SIRT1 functions under prolonged
starvation conditions:
A) High NAD+ activates it to increase expression of both gluconeogenesis enzymes and
mitochondrial proteins. X
B) High NADH activates it to increase expression of both gluconeogenesis enzymes and
mitochondrial proteins.
C) High NAD+ activates it to decrease expression of both gluconeogenesis enzymes and
mitochondrial proteins.
D) High NADH activates it to decrease expression of both gluconeogenesis enzymes and
mitochondrial proteins.
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19) Dinitrophenol (DNP) is a lipid-soluble H+-binding drug that equalizes the concentration of
H+ across the inner mitochondrial membrane. Which of the following would you predict to
occur upon addition of DNP to an actively respiring preparation of isolated mitochondria
with pyruvate as an oxidizable carbon substrate (assume that pyruvate is able to cross the
mitochondrial membranes)
A)
B)
C)
D)
halt in pyruvate oxidation but continuation in ATP synthesis
continuation in pyruvate oxidation but halt in ATP synthesis X
halt in both pyruvate oxidation and ATP synthesis
continuation in both pyruvate oxidation and ATP synthesis
20) You used Na+-Azide in your lab to poison the normal flow of electrons through the Electron
Transport Chain and force the electrons to an artificial electron acceptor that undergoes a color
transformation upon accepting electrons. Which of the following would you predict to occur
upon addition of Na+-Azide to the actively respiring preparation of isolated mitochondria of
question #32:
A)
B)
C)
D)
halt in pyruvate oxidation but continuation in ATP synthesis
continuation in pyruvate oxidation but halt in ATP synthesis
halt in both pyruvate oxidation and ATP synthesis X
continuation in both pyruvate oxidation and ATP synthesis
21) Which of the following subunits of ATP synthase is primarily responsible for translocating
H+ across the inner mitochondrial membrane during ATP synthesis:
A)
B)
C)
D)
α subunit
c subunit x
β subunit
γ subunit
22) Which of the following mutations in the c subunit of ATP Synthase would you predict to
have the LEAST deleterious effect on its ability to synthesize ATP:
A) mutating Asp61 to Ala
B) mutating Asp61 to Arg
C) mutating Asp61 to His
D) mutating Asp61 to Glu x
23) Which of the following has been shown to life or health span-extending activities in a variety
of species:
A) over-expressing Sirt1 enzyme
B) restricted calorie diet
C) mutations in proteins of the insulin-signaling pathway
D) all of the above x
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24) Which of the following amino acid sequences would be most likely to form an amphipathic
helix as found in ion channel proteins:
Amino
Acid #:
A)
B)
C)
D)
1 2 3 4 5 6
7 8
9 10 11 12 13 14 15 16 17
His-Lys-Arg-His-His-Arg-Gly- Ile-Glu-Lys-Arg-Lys-Lys-Arg-Arg-Arg-His
Met-Ala-Val-Lys-Gly-Val-Leu-His-Leu-Ile- Leu-Lys-Leu-Val-Ile-Arg-Leu x
Val-Ala-Gly-Val-Leu-Val-Leu- Ile-Gly-Met-Leu-Ile-Leu-Leu-Val-Gly-Leu
Ile-Pro-Leu-Pro-Val- Met-Pro-Gly-Pro-Ala-Val- Pro-Ile-Leu- Val-Pro-Gly
25) Which of the same set of polypeptide sequences would be LEAST likely to form an alpha
helix of any kind, because it contains helix-breaking amino acids that induce a bend in
an α-helix:
Amino
Acid #:
A)
B)
C)
D)
1 2 3 4 5 6
7 8
9 10 11 12 13 14 15 16 17
His-Lys-Arg-His-His-Arg-Gly- Ile-Glu-Lys-Arg-Lys-Lys-Arg-Arg-Arg-His
Met-Ala-Val-Lys-Gly-Val-Leu-His-Leu-Ile- Leu-Lys-Leu-Val-Ile-Arg-Leu
Val-Ala-Gly-Val-Leu-Val-Leu- Ile-Gly-Met-Leu-Ile-Leu-Leu-Val-Gly-Leu
Ile-Pro-Leu-Pro-Val- Met-Pro-Gly-Pro-Ala-Val- Pro-Ile-Leu- Val-Pro-Gly x
26) The molecule diagrammed below belongs to which of the following classes of lipids:
A)
B)
C)
D)
phosphoglyceride
shingolipid x
glycolipid
cholesterol
27) Which of the following lipid compositions would you predict to find in the plasma
membrane surrounding a protein with very long FRAP time:
A)
B)
C)
D)
saturated phospholipids x
cis unsaturated phospholipids
phospholipids with fatty acids containing multiple C-C double bonds.
low cholesterol concentration dispersed throughout the membrane
28) Which of the following membrane transport proteins becomes localized on the plasma
membrane in response to hormonal stimulation:
A) H+/K+ ATPase
B) glucose transporter (GLUT4)
C) Voltage-gated K+ ion channel
D) A and B, not C x
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29) Which of the following proteins is responsible for pumping H+ concentration into the
stomach in response to food consumption resulting in hormone stimulation:
A) H+/K+ ATPase x
B) Neuroreceptors
C) Voltage-gated K+ ion channel
D) Na+/K+ ATPase
30) Which of the following proteins is responsible for the depolarization of a postsynaptic
membrane to threshold in generating an action potential:
A) Na+/K+ ATPase
B) Voltage-gated K+ ion channel
C) Voltage-gated Na+ ion channel
D) Neuroreceptors x
31) Which of the following proteins is responsible for the full depolarization of a postsynaptic
membrane only after reaching the threshold depolarization:
A) Na+/K+ ATPase
B) Voltage-gated K+ ion channel
C) Voltage-gated Na+ ion channel x
D) Neuroreceptors
32) Mutations in the gene for which of the following transporter proteins are thought to have
conferred selective resistance to the cholera bacterium:
A) H+/K+ ATPase
B) Glucose transporter (GLUT4)
C) CFTR Cl- channel x
D) Na+/K+ ATPase
33) Mutations in the gene for which of the following transporter proteins are responsible for
Cystic Fibrosis disease causing thickening of mucous secretions:
A) H+/K+ ATPase
B) Glucose transporter (GLUT4)
C) CFTR Cl- channel x
D) Na+/K+ ATPase
34) Proton Pump Inhibitor (PPI) drugs treat acid reflux by:
A)
B)
C)
D)
inhibiting binding of Histamine to Histamine Receptors of the stomach lining
inhibiting the fusion of vesicles bearing H+/K+ ATPase with the plasma membrane
inhibiting the action of H+/K+ ATPase on the plasma membrane x
neutralizing the excess acid inside the stomach
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35) Which of the following membrane proteins functions in active transport across the
membrane:
A)
B)
C)
D)
Neuroreceptors
Voltage-gated K+ channel
Glucose transporter (GLUT4)
CFTR Cl- channel x
36) The anti-depressive drug, Prozac, affects neurostimulation by:
A) activating release of a neurotransmitter
B) inhibiting release of a neurotransmitter
C) inhibiting destruction of a neurotransmitter in the synaptic cleft x (mistakenly keyed
correct on key to computer center)
D) inhibiting reuptake of a neurotransmitter in the synaptic cleft X (CORRECT
RESPONSE)
37) Amphipathic detergents, such as SDS, are sometimes used to induce protein unfolding.
Which of the following bonds/interactions would you MOST expect to be involved in this:
A) Hydrogen bonds
B) Hydrophobic interactions x
C) Disulfide bonds
D) Covalent bonds
38) Which of the following findings was discussed in the Charlie Rose Brain Series segment on
autism:
A) Mutations in genes of immune system function are associated with autism.
B) Mutations in genes of neural synaptic function are associated with autism.
C) Autism and Williams Syndrome are associated with reciprocal Copy Number Variant
mutations that arose spontaneously in the germline.
D) Both B and C x
39) Which of the following findings was discussed in the Charlie Rose Brain Series segment on
multiple sclerosis:
A) Mutations in genes of immune system function are associated with Multiple Sclerosis.
B) Mutations in genes of neural synaptic function are associated with Multiple Sclerosis.
C) Multiple Sclerosis shares disease susceptibility mutations with other autoimmune
disorders such as Diabetes Type I.
D) Both A and C x
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40) Which of the following domains of the voltage-gated K+ is responsible for preventing it from
re-opening for a brief refractory period immediately following channel opening:
A)
B)
C)
D)
S4 helix amphipathic helix
non-amphipathic helices
inactivation peptide x
K+-binding domain
FILL-IN-BLANK
WORD BANK Some options may be used more than once, and others may not be used at all.
α-helix
β-sheet
calorie restricted diet
depolarization to threshold
full depolarization
insulin signaling
into
K+
ligand-gated ion channel
Na+
Na+/K+ ATPase
NAD+
Neuroreceptors
out of
PrPc
PrPsc
repolarization
Resveratrol
Sirt1
Superoxide Dismutase
superoxide free radicals
voltage-gated ion channel
Voltage-gated K+ channel
Voltage-gated Na+ channel
+ 70 mV
-70 mV
+50 mV
-50 mV
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1) Use the word bank to fill in the blanks in the description of the steps in an action potential.(17 pts)
The Na+/K+ATPase uses the energy of ATP hydrolysis to move 3 Na+ out for every 2 K+ it
moves in across the post-synaptic membrane, establishing a charge gradient and a concentration gradient
for both ions across the membrane at rest, measured as -70 mV . Neurotransmitters released from the presynaptic neuron bind to neuroreceptors on the plasma membrane of the post-synaptic cell, stimulating it
to open its ion channel, allowing some Na+ to flow into the cell and bring about a depolarization to
threshold to -50 mV. This stimulates voltage-gated Na+ channels, to open, allowing even more Na+ to
rush into the cell until the membrane undergoes a full depolarization to +50 mV. This change in
membrane potential then stimulates voltage-gated K+ channels to open, allowing K+ to now flow out of
the cell. This brings about a repolarization of the membrane to near its resting membrane potential.
2) Use the word bank to fill in the blanks in the description of life span extending effects. (7 pt)
Destructive superoxide free radicals are an unwanted by-product of aerobic metabolism. They result
from the escape of singlet electrons from the Electron Transport Chain of mitochondria during oxidative
phosphorylation. Superoxide Dismutase (SOD) eliminates these free radical species by converting them
to H2O2. Overexpression of this enzyme or the transcriptional regulator of starvation/stress response
genes (Sirt1) also extend life/health span in a variety of species, presumably by reducing the amount of
these destructive species in cells. Because this transcriptional activator is dependent on the molecule,
NAD+, for activity, its activity is stimulated by increased levels of this molecule during starvation.
3) Use the word bank to fill in the blanks in the description of prion protein diseases. (6 pt)
A number of neurodegenerative diseases are being recognized as protein folding disorders. Jacob
Creutzfeld disease results from mutations in the PrP protein which predispose the protein to adopt an
abnormal conformation (called PrPsc) and is also capable of shifting the conformation of the normal
protein (called PrPc) to the abnormal one. X-ray crystallography and NMR spectroscopy of the two
protein conformers showed that the N-terminal region of the protein adopts an α-helical conformation in
the normally folded protein, whereas the abnormal protein adopts a β-sheetconformation in the same
region...
SID#:___________________________
Multiple Choice:_______________/ 80
Fill-in-Blank: _______________/ 20
Total Grade:
10
_______________/100