80 terms

Bio 1107 Exam 2

From Practice Exams 1-4
B. Bacterium do not have organelles like mitochondria, but ribosomes have been observed in the cytoplasm in prokaryotes.
1) Which would NOT be found in a bacterium
A) DNA B) mitochondria
C) phospholipid D) ribosome
2) Which statement is CORRECT?
A) Plants do not have mitochondria
B) Animals cells do not have a central
C) Nuclei do not contain proteins
D) The lysosome is only found in
prokaryotic cell
3) Why are lipids and proteins free to move
laterally in membranes?
A) Hydrophilic portions of the lipids are
in the interior of the membrane.
B) Molecules such as cellulose can pull
them in various directions.
C) The interior of the membrane is filled
with liquid water.
D) There are only weak hydrophobic
interactions in the interior of the
E) Lipids and proteins repulse each other
in the membrane
4) Which statement is CORRECT?
A) During exocytosis, vesicles in the
cytoplasm discharge their contents
outside the cell.
B) During endocytosis, particles enter the
cytoplasm through a pore in the
plasma membrane.
C) Human cells do not undergo exocytosis
since the elimination of waste products
is carried out by the excretory system.
D) Exocytosis transports waste but no
other materials outside of the cell
D, decrease. Per DG=DH - DS(T), DG will be more negative with rising entropy. Also, you can look at it as a whole breaking down into pieces, which increases disorganization.
5) Within a closed system, as entropy increases
the free energy must
A) increase then decrease
B) be constant
C) decrease
D) increase
B, plasma membrane of the host cell. Viruses can steal this membrane and use it as a viral envelope.
6) Some viruses have a phospholipid envelope
that originates from the
A) nucleus of the host cell.
B) plasma membrane of the host cell.
C) synthesis of proteins and lipids inside
the virus.
D) synthesis of lipids in the virus and
proteins in the host cell
7) Which statement about enzymes is FALSE?
A) They do not change the chemical
reactions they promote.
B) They catalyze specific chemical
C) Their speed up chemical reactions by
providing activation energy
D) They function best at a particular pH
B. ATP production does not occur in the mitochondria in plant cells. Glycolysis and fermentation can both occur in the absence of O2.
8) Which statement about cell respiration is
A) animals and plants both perform cell
B) All ATP production takes place in the
C) CO2
is made in the Citric Acid Cycle
D) Glycolysis and fermentation both occur
in the absence of O2
9) Which statement is FALSE?
A) NADH is last electron accepter of the
electron transport chain.
B) Electrons harvested from the oxidation
of pyruvate are eventually given to O2.
C) Oxidation of glucose produces two
ATP, 2 NADH, and 2 pyruvate
D) The ETC uses electrons from oxidation
of glucose to drive proton pump
10) When electrons move closer to a more
electronegative atom, what happens?
A) The more electronegative atom is
oxidized, and entropy decreases.
B) The more electronegative atom is
oxidized, and energy is released.
C) The more electronegative atom is
reduced, and entropy decreases.
D) The more electronegative atom is
reduced, and energy is released
11) Most weight loss programs recommend
aerobic exercise as a way to lose fat because
fatty acids are used by cells for energy during
aerobic respiration, but not at all during
anaerobic respiration. That is because
A) fatty acids are converted into acetyl
CoA which only enters the aerobic
pathway of the Krebs cycle.
B) anaerobic respiration occurs in the
cytoplasm, and fats are insoluble in the
C) fatty acids inhibit the enzymes
involved in anaerobic pathways.
D) fatty acids are converted into pyruvate
and eventually lactic acid.
E) fatty acids block transfer of electrons to
the electron transport chain.
A, facilitated diffusion. Endocytosis would be inefficient, active transport would require a lot of ATP, and the relative concentrations would not support osmosis. With facilitated diffusion, the cell will support entry of glucose without expending energy.
12) You put a cell in glucose solution and
measure the concentration of glucose inside
the cells after 30 minutes. You repeat the
experiment using double the concentration of
glucose in the solution and find that the
concentration of glucose inside the cells also
doubled. This result suggests that glucose
enters the cells by means of:
A) facilitated diffusion
B) endocytosis
C) active transport
D) osmosis
13) An animal cell releases calcium into the
surrounding medium. When a chemical that
interferes with mitochondrial function is
added to the cell, it stops releasing calcium.
Based on these results, which statement is
most likely CORRECT?
A) The calcium concentration outside the
cell was higher than the concentration
immediately inside the cell
B) Mitochondria need calcium to function
C) The calcium concentration outside the
cell was lower than the concentration
immediately inside the cell
D) Calcium was released from the cell by
14) Which of the following would NOT be
considered to be energetically spontaneous?
A) triglyceride --> fatty acids and glycerol
B) movement of ions through a
membrane channel from an area of
high to an area of low concentration.
C) an exergonic reaction
D) the energy of the products is greater
than the energy of the reactant
Equation did not copy. But turning glucose into CO2 is exergonic, and the carbon in glucose is oxidized.
15) Which statement best describes this reaction?
A) endergonic, C3H8
is oxidized
B) exergonic, C3H8
is oxidized
C) endergonic, C3H8
is reduced
D) exergonic, C3H8
is reduced
16) Long distance runners are often thin and run
slower than sprinters, who usually have large
muscles. What best explains this difference?
A) Being lighter and running slower helps
long distance runners ensure their
muscles receive enough oxygen for
aerobic respiration.
B) Sprinters can run faster because their
large muscles produce less lactic acid
than muscles in long distance runners.
C) Long distance runners run slower
because they use energy from
anaerobic respiration, which makes less
ATP than aerobic respiration.
D) Long distance runners burn more
energy than sprinters, which makes it
difficult for them to gain weight
A. Glycolysis is not part of aerobic respiration. So food (not simply glucose, which requires glycolysis) will give off electrons to NADH, the ETC, and end up in bonds with highly EN oxygen.
17) During aerobic respiration, electrons travel
downhill in which sequence?
A) food→NADH →ETC →oxygen
B) food→krebs cycle→ATP →NAD+
C) glucose→pyruvate →ATP →oxygen
D) glucose→ATP →electron transport
chain →NADH
E) food→glycolysis→krebs cycle→
18) Mammals that hibernate have "brown fat"
cells that contain many mitochondria. These
cells contain an protein that allows hydrogen
ions to freely cross membranes. The most
likely function of these cells is:
A) to make and store fat
B) to produce large amounts of ATP
C) to produce heat
D) to conserve energy
19) The ETC pumps hydrogen ions from the
stroma to the intermembrane space. If this
process is disrupted, you should see
A) an increase in the pH of the
intermembrane space
B) a drop in the pH of the intermembrane
space and an increase in the stroma
C) no change in the pH of the
intermembrane space
D) a drop in the pH of the intermembrane
20) Yeast cells that have defective mitochondria
incapable of respiration will be able to grow
by catabolizing which of the following carbon
sources for energy?
A) fatty acids
B) proteins
C) Such yeast cells will not be capable of
catabolizing any food molecules, and
will therefore die.
D) glucose
E) glucose, proteins, and fatty acid
1) All cells have
A) a nucleus and chloroplasts
B) a cell wall and nucleus
C) ribosomes and nucleus
D) a cell membrane and cytoplasm
2) Which best explains why plant cells can grow
larger than animal cells?
A) photosynthesis produces more energy
than does respiration.
B) much of the volume of a plant cell is
taken up by a metabolically inactive
central vacuole.
C) plant cells have a cell wall which
makes their surface to volume ratio
very large.
D) plants use their energy for growth
while animals spend much of their
energy on movement.
E) plant cells need less food than animal
B, amphipathic with at least one hydrophobic region. Integral membrane proteins are lodged into the membrane, with a hydrophilic region exposed to a region with water and the other hydrophobic region facing the hydrophobic pieces of the rest of the membrane.
3) For a protein to be an integral membrane
protein, it must be
A) exposed on only one surface of the
B) amphipathic, with at least one
hydrophobic region.
C) hydrophilic.
D) completely covered with
E) hydrophobic
D, endocytosis. Endocytosis is the re-folding of the cell membrane to encapsulate another substance. Anything else to do with diffusion and transport requires some sort of protein.
4) Which mode of transport does NOT require a
A) simple diffusion
B) facilitated diffusion
C) active transport
D) endocytosis
C, it is exergonic. -DG refers to exergonic reactions, while +DG is endergonic as well as anabolic. Also, the reaction is spontaneous, meaning it requires no energy. Lastly the reaction is not necessarily in equilibrium.
5) If ΔG of a chemical reaction is negative and
ΔS is positive, you can conclude that
A) it is in equilibrium
B) it is endergonic
C) it is exergonic
D) it requires energy
E) it is anabolic
B. A large number of new virus particles will be released at one time when the host cell is destroyed. Compare this to the lysogenic cycle, in which the virus' DNA is imparted into the host cell's DNA and it continues to reproduce for generations without killing off the host.
6) Which is characteristic of the lytic cycle?
A) The virus-host relationship usually
lasts for generations.
B) A large number of new virus particles
are released at a time.
C) The viral genome replicates without
destroying the host.
D) Many bacterial cells containing viral
DNA are produced.
E) Viral DNA is incorporated into the host
7) Which of the following statements is TRUE
about enzyme-catalyzed reactions?
A) The reaction is faster than the same
reaction in the absence of the enzyme.
B) Enzyme-catalyzed reactions require
energy to activate the enzyme.
C) The reaction always goes in the
direction toward chemical equilibrium.
D) The free energy change of the reaction
is opposite from the reaction that
occurs in the absence of the enzyme.
E) Enzyme-catalyzed reactions release
more free energy than noncatalyzed
8) Which statement is FALSE?
A) Pyruvate from glycolysis is converted
to acetyl-CoA in the mitochondria.
B) For each glucose molecule, the citric
acid (Kreb's) cycle produces more ATP
than glycolysis.
C) The energy to make ATP comes from a
proton gradient across the
mitochondrial membrane.
D) Some energy from ATP is required to
begin glycolysis
9) Which is NOT a product of glycolysis?
A) Pyruvate B) NADH
10) Fats are a better source of energy than
carbohydrates because
A) fats can be broken down by glycolysis
without entering the mitochondrion
B) fats cross the cell membrane more
easily than carbohydrates.
C) hydrolysis of fats is faster than
hydrolysis of carbohydrates.
D) oxidation of fats produces more ATP.
E) fats are converted to fatty acids that
directly enter the citric acid cycle
11) You have a friend who lost 7 kg (about 15
pounds) of fat on a regimen of strict diet and
exercise. How did the fat leave her body?
A) It was broken down to amino acids and
eliminated from the body.
B) It was released as CO2
and H2O.
C) It was converted to urine and
eliminated from the body.
D) It was converted to ATP, which weighs
much less than fat.
E) It was converted to heat and then
12) The size cells can grow to is limited. Of the
cells shown below, which one is likely to
experience the greatest difficulty as it grows
larger assuming it retains the same shape?
13) If you could suddenly remove all the protein
molecules from the plasma membrane of a
cell (without destroying the cell), which of
the following would you expect to happen?
A) The plasma membrane would become
much less fluid-like.
B) Movement of all molecules across the
plasma membrane would stop.
C) Movement of ions across the plasma
membrane would stop.
D) Large macromolecules would diffuse
out of the cell.
E) The amount of cholesterol in the
plasma membrane would decrease
14) You add cyanide to an animal cell to stop
aerobic respiration. Which of the
following is most likely to be affected?
A) hydrolysis of proteins into amino acids
B) lateral movement of phospholipids in
the cell's plasma membrane
C) facilitated diffusion of water across the
cell membrane
D) movement of K+ into the cell up its
concentration gradient
A, same +3.6 kCal/mol. Enzymes do not change the free energy of a reaction, just the activation energy (which is not included in the equation for finding free energy) so that it may occur faster.
15) The ΔG of reaction is +3.6 kCal/mol. If you
add an enzyme to catalyze this reaction the
ΔG should now be:
A) +3.6 kCal/mol
B) < +3.6 kCal/mol
C) it can't be determined without
additional information
D) > +3.6 kCal/mo
16) Why does aerobic respiration make more ATP
than anerobic respiration?
A) more energy is obtained through
glycolysis with aerobic than anerobic
B) there is a still a lot of unreleased energy
in the final breakdown products of
anerobic respiration.
C) the enzymes associated with aerobic
respiration are slower and less efficient
than those associated with aerobic
D) aerobic respiration requires O2 while
anerobic does not
17) Hibernating animals (sleep all winter) have
tissues containing mitochondria with a
membrane protein that accelerates electron
transport while blocking the synthesis of
ATP. What is the consequence of this?
A) Pyruvate is converted to lactic acid by
anaerobic fermentation.
B) Energy is saved because glycolysis and
the citric acid cycle shut down.
C) Hibernating animals can make fat and
not waste energy on respiration.
D) Hibernating animals do not have
enough energy to keep warm, so they
must sleep through the winter.
E) Most of the energy of respiration is
converted to heat.
18) A metabolic poison that would most directly
interfere with glycolysis is one that
A) reacts with oxygen and depletes its
concentration in the cell
B) oxidizes NADH to NAD+
C) blocks passage of electrons along the
electron transport chain
D) closely mimics the structure of glucose
but is not metabolized
E) binds to pyruvate and inactivates i
19) An organism is discovered that thrives both
with and without oxygen. As oxygen is
removed from the organism's environment,
the consumption of sugar increases but the
organism does not gain much weight. The
best explanation for this is that the organism
A) must break down more glucose using
less efficient anerobic respiration to
maintain ATP levels
B) must be converting the glucose to fat
which it can break down in the absence
of oxygen
C) must use a molecule other than oxygen
to accept electrons from the electron
transport chain.
D) must break down more glucose to
speed up aerobic respiration to
counteract the effects of low oxygen
20) Which of the following most accurately
describes what happens in the ETC?
A) Energy of the electrons increases at
each step.
B) Each electron carrier alternates
between being reduced and being
C) Molecules in the chain give up some of
their potential energy.
D) ATP is generated at each step
1) If a cell contains enzymes, DNA, ribosomes, a
plasma membrane, and mitochondria. It
could be a cell from
A) nearly any eukaryotic organism.
B) a plant or an animal.
C) an animal, but not a plant.
D) a bacterium.
E) any kind of organism
2) Which structure is NOT composed of
A) chloroplast B) chromosome
C) golgi D) lysosome
3) What do plant cell walls and the extracellular
matrix of animal cells have in common?
A) They limit the passage of small
B) They have functional connections with
the cytoskeleton inside the cell.
C) They form rigid structures that provide
structural support for cells but limit
their expansion.
D) Their proteins are made by free
cytoplasmic ribosomes.
E) They are largely composed of
phospholipids and glycoproteins
4) Motor proteins provide for molecular motion
in cells by interacting with what types of
cellular structures?
A) membrane proteins
B) ribosomes
C) mitochondria
D) cellulose fibers in the cell wall
E) cytoskeletal structures
5) Which would likely move through the lipid
bilayer of a plasma membrane most rapidly?
A) K+ B) starch
C) CO2 D) an amino acid
D. Chemiosmosis joins the electron transport chain to oxidative phosphorylation, and in between joins ADP and Pi to make ATP. More specifically, it uses ATP synthase to allow H+ ions back in to the mitochondrial matrix and uses the energy release to fuse the above reactants into ATP.
6) The ATP is made during glycolysis by
A) oxidation of NADH to NAD+
B) electron transport.
C) substrate-level phosphorylation.
D) chemiosmosis
A. Anabolic pathways use energy (therefore are nonspontaneous), and combine monomers into polymers.
7) Which is (are) true for anabolic pathways?
A) They consume energy to make
polymers from monomers.
B) They are usually highly spontaneous
chemical reactions.
C) They release energy as they degrade
polymers to monomers.
D) They do not depend on enzymes
E. Glycolysis first involves more molecules bonding to glucose, and enzymes can lower the activation energy of exergonic reactions. However, activation energy does not refer to the total energy released by a reaction (enthalpy does this).
8) Which statement is FALSE?
A) Enzymes can catalyse both exergonic
and endergonic reactions
B) An exergonic reaction is one in which
energy is released
C) The first steps of glycolysis are
endergonic reactions
D) Catabolism refers to the breakdown of
complex molecules into more simple
E) Activation energy refers the total
energy released by a reaction
B. Free energy is released as electrons move from moderately EN atoms to bond with more EN atoms.
9) Why does the oxidation of organic
compounds by molecular oxygen to produce
and water release free energy?
A) The covalent bond in O2
is unstable
and easily broken by electrons from
organic molecules.
B) Electrons are being moved from atoms
that have a lower affinity for electrons
(such as C) to atoms with a higher
affinity for electrons (such as O).
C) The covalent bonds in organic
molecules and molecular oxygen have
more kinetic energy than the covalent
bonds in water and carbon dioxide.
D) The oxidation of organic compounds
can be used to make ATP.
E) Electrons have a more potential energy
when associated with water and CO2
than they do in organic compounds
10) In the absences of oxygen, cells capable of
A) accumulate pyruvate
B) no longer produce ATP
C) accumulate glucose
D) oxidize NADH to produce NAD+
11) Which statement is FALSE?
A) Most biochemical reactions in your
body are irreversible.
B) The products of a reaction can have less
energy than the reactants.
C) Even exergonic reactions require some
activation energy
D) The products of a reaction can have
more energy than the reactants.
12) Which correctly describes some aspect of
protein secretion from prokaryotic cells?
A) In prokaryotes, the ribosomes that are
used for the synthesis of secreted
proteins are located outside of the cell.
B) Prokaryotes are unlikely to be able to
secrete proteins because they lack an
endomembrane system.
C) Proteins secreted by prokaryotes are
made by ribosomes bound to the
cytoplasmic side of the cell membrane.
D) The mechanism of protein secretion in
prokaryotes is probably the same as
that in eukaryotes
13) You isolate two different types of protozoa
(eukaryotes). When you give them glucose
and grown them in an open container, one
type of protozoa grows more quickly than the
other. When you provide them with glucose
and grow them in an airtight container, both
types grow at the slower rate. Which
statement could best explains this result?
A) One type of protozoa had functional
mitochondria, the other did not.
B) Neither type of protozoa can use
glucose as a food source.
C) One type of protozoa had functional
lysosomes, the other did not.
D) One type of protozoa could use glucose
as a food source, the other could not
14) Most CO2
from catabolism is released during
A) electron transport.
B) glycolysis.
C) oxidative phosphorylation.
D) lactate fermentation.
E) the citric acid cycle
15) Viagra blocks activity of phosphodiesterase-5
(PDE5) in the following reaction:
Blocking the enzyme results in a buildup of
B) cGMP and GMP
16) During a laboratory experiment, you discover
that an enzyme-catalyzed reaction has a ∆G
of -20 kcal/mol. If you double the amount of
enzyme in the reaction, what will be the ∆G
for the new reaction?
A) +40 kcal/mol
B) 0 kcal/mol
C) -40 kcal/mol
D) +20 kcal/mol
E) -20 kcal/mo
D, the cell will take up water. The water will flow into the cell with high solute concentration to even things out. Also, the cell membrane will not lyse because plant cells are stabilized by cell walls and will not rupture in isotonic solutions.
17) When a plant cell, such as one from a peony
stem, is submerged water containing very
little solute, what is likely to occur?
A) The cell breakdown in the water.
B) It will neither gain nor lose water.
C) The cell will lose water.
D) The cell will take up water.
E) The cell membrane will lyse
18) All of the following occur during completely
anaerobic breakdown of glucose in muscle
cells, EXCEPT:
A) release of CO2
B) production of pyruvate
C) lactic acid production
D) NADH converted to NAD+
E) creation of AT
19) Which statement is CORRECT regarding a
fasting cell performing aerobic respiration?
A) Entropy of the system decreases.
B) The free energy of the system increases.
C) The free energy remains constant.
D) Entropy is converted into free energy.
E) Entropy of the system increases
20) What would you see if you could follow the
location of the dye by live-cell fluorescence
microscopy if the red fluorescent lipid
dye-labeled HIV membrane fuses with the
target cell plasma membrane?
A) A spot of red fluorescence will remain
on the infected cell's plasma
membrane, marking the site of
membrane fusion and HIV entry.
B) Red fluorescence will move into the
cytoplasm as well as remain in the cell
membrane after delivering the capsid.
C) The dye-labeled lipids will diffuse in
the infected cell's plasma membrane
and become difficult to detect.
D) A spot of red fluorescence will move
into the infected cell's cytoplasm
1) Most cells observed in nature fall within
certain size ranges due to the
A) limited strength and integrity of the
plasma membrane, large cells can't be
structurally supported
B) need for a surface area sufficient to
support the cell's metabolic needs
C) differences in plasma membranes
between prokaryotes and eukaryotes
D) rigid cell walls that limit the expansion
of cells
E) evolutionary progression in cell size;
more primitive cells have smaller size
C, cytoskeleton. They cytoskeleton is responsible for cell motility, including movement of organelles.
2) You treat an animal cell with a chemical. The
cell rounds up and materials in the cell stop
moving but cell respiration continues. The
chemical most likely affects the cell's:
A) membrane B) ER
C) cytoskeleton D) cell wal
C. Both plant cells and animal cells have mitochondria.
3) Which of the following is NOT a basic
difference between plant and animal cells?
A) Plants have cell walls, and animal cells
do not.
B) The cell wall plays a major role in
determining plant cell shape while the
cytoskeleton plays a major role in
determining animal cell shape.
C) Animal cells have mitochondria but
plant cells do not.
D) Plant cells contain chloroplasts, but
animal cells do not.
4) Which would probably have the LEAST
difficulty diffusing across a cell membrane?
A) pyruvate B) ATP
C) ethyl alcohol D) glucose
A, cofactor necessary for enzyme activity.
5) Zinc, an essential trace element, is present in
the active site of carboxypeptidase enzyme.
The zinc most likely functions as a(n)
A) cofactor necessary for enzyme activity.
B) allosteric activator of the enzyme.
C) competitive inhibitor of the enzyme.
D) noncompetitive inhibitor of the
E) coenzyme derived from a vitamin
D, cells need a constant input of energy to maintain a high level of organization. Cells will inevitably lose some energy as heat to the universe, so they need an influx of energy to replace it and stay organized.
6) Which statement is representative of the
second law of thermodynamics?
A) Every energy transformation by a cell
decreases the entropy of the universe.
B) Heat is a form of energy that can be
used by most organisms to do work.
C) Conversion of energy from one form to
another is always accompanied by
some gain of free energy.
D) Cells need a constant input of energy to
maintain a high level of organization
7) Which statement is CORRECT regarding
aerobic respiration?
A) the energy for oxidative
phosphorylation comes from ATP.
B) energy to make ATP comes from
protons moving down a concentration
C) glucose is first converted to pyruvic
acid in the mitochondrion.
D) The electron transport chain makes
ATP by pumping electrons across the
cell membrane
8) Which statement best describes this reaction?
+ 6 O2 →6 CO2
+ 6 H2O +Energy
A) CO2
is reduced and O2
is oxidized.
B) O2
is oxidized and H2O is reduced.
C) C6H12O6
is oxidized and O2
D) C6H12O6
is reduced and CO2
E) O2
is reduced and CO2
is oxidized
B, IV only. Oxidative phosphorylation refers to the loss of electrons ,which is carried out by ETC.
9) Oxidative phosphorylation is performed
during which stage(s) of cell respiration?
I. Glycolysis
II. pyruvate --> Acetyl-CoA
III. Citric Acid Cycle
A) I, II, and III B) IV only
C) I only D) I and II
10) CO2 produced during aerobic respiration in
A) the mitochondria only
B) both the cytoplasm and mitochondria
C) the cytoplasm only
11) During intense exercise, as skeletal muscle
cells switch to anerobic respiration, the
human body will increase its catabolism of
A) fats only.
B) proteins only.
C) fats, carbohydrates, and proteins.
D) fats and proteins only.
E) carbohydrates only.
12) Protozoans living in pond water must use
exocytosis to get rid of excess water in their
cytoplasm? Why might this be necessary?
A) Protozoans take up water by
endocytosis; therefore, they must expel
it by exocytosis.
B) Pond water is hypotonic to the
protozoan cytoplasm.
C) Pond water is isotonic to the protozoan
D) Water cannot diffuse across the
protozoan plasma membrane.
E) Pond water is hypertonic to the
protozoan cytoplasm
13) Which of the following reactions would
release energy?
A) converting CO2
and H2O into glucose
B) adding a phosphate group to ADP to
form ATP
C) converting lactose into glucose and
D) A and B would release energy.
E) All of the above would release energy
14) The chemical reactions of cell respiration are
virtually identical between prokaryotic and
eukaryotic cells. In eukaryotes, ATP is made
primarily on the inner membrane of the
mitochondria. In light of the endosymbiont
theory for the evolutionary origin of
mitochondria, where is most ATP synthesis
likely to occur in prokaryotic cells?
A) on the endoplasmic recticulum
B) on the inner mitochondrial membrane
C) in the cytoplasm
D) on the inner nuclear envelope
E) on the plasma membrane
D, higher ethanol levels in the woman. Women typically have lower alcohol tolerances than men, because the enzyme cannot reduce ethanol into acetaldehyde as quickly.
15) The following reaction occurs in your body to
break down alcohol you consume. In
women's bodies the enzyme involved in this
pathway is only 40% as active as it is in men's
bodies. Which means that if a woman
consumes the same amount of ethanol as a
man, after an hour you would expect to see:
A) Higher alcohol levels in the man.
B) Lower acetaldehyde levels in the man.
C) Higher acetaldehyde levels in the
D) Higher ethanol levels in the woman.
E) More alcohol dehydrogenase in the
16) You place some animal cells in a solution
containing Na+ and K+ ions. After 10
minutes, the concentration of Na+ had
increased in the solution, but that of K+ had
decreased. When you give the cells glucose
and repeat the experiment, the concentration
of Na+ in the solution increased faster, but the
decrease in K+ was the same as in the first
experiment. What best explains these results?
A) Sodium leaves the cells by passive
transport and potassium enters the
cells by active transport.
B) Sodium leaves and potassium enters
the cells by passive transport.
C) The cell's plasma membrane is more
permeable to sodium than potassium
D) Glucose enters the cells by passive
E) Sodium is excreted from the cells by
active transport and potassium enters
by passive transport
17) What accepts the electrons from NADH
during fermentation in humans?
C) O2
D) pyruvic acid
E) CO2
18) Which of the following is FALSE regarding
an enzyme catalyzed reaction?
A) The uncatalyzed reactions requires
more activation energy than the
uncatalyzed reaction.
B) The free energy change between the
reactants and products is the same for
both the enzyme catalyzed and
uncatalyzed reactions.
C) Both the enzyme catalyzed and
uncatalyzed reactions reach
equilibrium at the same rate.
D) The enzyme speeds up both the
forward and reverse reactions of a
reversible reaction.
19) Fatty acids usually have an even number of
carbons in their structures. They are
catabolized by a process called
beta-oxidation. The end products of the
metabolic pathway are two carbon acetyl
groups. Where would these groups most
likely enter the cell respiration pathway?
A) They directly enter the Krebs cycle.
B) They are directly decarboxylated by
pyruvate dehydrogenase.
C) They directly enter the electron
transport chain.
D) They directly enter the energy-yielding
stages of glycolysis
HIV viral nucleic acid molecules are enclosed in a protein
capsid, which is itself contained inside a lipid envelope.
One hypothesis for viral entry into cells is that the virus
binds to proteins on the surface of a cell and fuses with the
plasma membrane, releasing the viral capsid into the
cytoplasm. An alternative hypothesis is that HIV is
brought into the cell via receptor-mediated endocytosis,
and membrane fusion occurs in the endocytotic vesicle. To
test these two hypotheses, researchers labeled the lipids on
the HIV membrane with a red fluorescent dye.
20) What would you see if you could follow the
location of the dye by live-cell fluorescence
microscopy if HIV is endocytosed first, and
then fuses with the endocytotic vesicle
A) A spot of red fluorescence will remain
on the infected cell's plasma
membrane, marking the site of
membrane fusion and HIV entry.
B) Red fluorescence will move into the
cytoplasm as well as remain in the cell
membrane after delivering the capsid.
C) The dye-labeled lipids will diffuse in
the endocytotic vesicle membrane and
become difficult to detect.
D) A spot of red fluorescence will move
into the infected cell's interior.