Download 1) Which of the following is (are) true for anabolic

1) Which of the following is (are) true for anabolic pathways?
A) They consume energy to build up polymers from monomers.
B) They do not depend on enzymes.
C) They are usually highly spontaneous chemical reactions.
D) They release energy as they degrade polymers to monomers.
2) Whenever energy is transformed, there is always an increase in the
A) free energy of the universe.
B) enthalpy of the universe.
C) free energy of the system.
D) entropy of the system.
E) entropy of the universe.
3) Which of the following statements is representative of the second law of thermodynamics?
A) Conversion of energy from one form to another is always accompanied by some gain of free energy.
B) Heat represents a form of energy that can be used by most organisms to do work.
C) Without an input of energy, organisms would tend toward decreasing entropy.
D) Every energy transformation by a cell decreases the entropy of the universe.
E) Cells require a constant input of energy to maintain their high level of organization.
4) Which of the following is true of metabolism in its entirety?
A) Metabolism utilizes all of an organism's resources
B) Metabolism manages the increase of entropy in an organism
C) Metabolism depends on a constant supply of energy from food
D) Metabolism is a property of organismal life
E) Metabolism depends on an organism's adequate hydration
5) The mathematical expression for the change in free energy of a system is
following is (are) correct?
A) H is the change in entropy, the energy available to do work.
B) S is the change in enthalpy, a measure of randomness.
C) T is the temperature in degrees Celsius.
D) G is the change in free energy.
6) A chemical reaction that has a positive
A) enthalpic.
B) endothermic.
C) spontaneous.
D) endergonic.
E) exothermic.
G
H-T S. Which of the
G is correctly described as
7) Which of the following statements is true concerning catabolic pathways?
A) They combine molecules into more energy-rich molecules.
B) They are usually coupled with anabolic pathways to which they supply energy in the form of ATP.
C) They are spontaneous and do not need enzyme catalysis.
D) They build up complex molecules such as protein from simpler compounds.
E) They are endergonic.
8) Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by
the enzyme sucrase results in
A) the release of water from sucrose as the bond between glucose and fructose is broken.
B) bringing glucose and fructose together to form sucrose.
C) production of water from the sugar as bonds are broken between the glucose monomers.
D) breaking the bond between glucose and fructose and forming new bonds from the atoms of water.
E) utilization of water as a covalent bond is formed between glucose and fructose to form sucrase.
9) A solution of starch at room temperature does not readily decompose to form a solution of simple sugars
because
A) starch hydrolysis is nonspontaneous.
B) the starch solution has less free energy than the sugar solution.
C) the activation energy barrier for this reaction cannot be surmounted.
D) the hydrolysis of starch to sugar is endergonic.
E) starch cannot be hydrolyzed in the presence of so much water.
10) The active site of an enzyme is the region that
A) is involved in the catalytic reaction of the enzyme.
B) binds the products of the catalytic reaction.
C) is inhibited by the presence of a coenzyme or a cofactor.
D) binds allosteric regulators of the enzyme.
Refer to Figure 8.1 to answer the following questions.
Figure 8.1
11) Which curve represents the behavior of an enzyme taken from a bacterium that lives in hot springs at
temperatures of 70°C or higher?
A) curve 1
B) curve 2
C) curve 3
D) curve 4
E) curve 5
12) Which curve was most likely generated from analysis of an enzyme from a human stomach where conditions
are strongly acid?
A) curve 1
B) curve 2
C) curve 3
D) curve 4
E) curve 5
13) Which curve was most likely generated from an enzyme that requires a cofactor?
A) curve 1
B) curve 2
C) curve 4
D) curve 5
E) It is not possible to determine whether an enzyme requires a cofactor from these data.
14) Zinc, an essential trace element for most organisms, is present in the active site of the enzyme
carboxypeptidase. The zinc most likely functions as a(n)
A) competitive inhibitor of the enzyme.
B) coenzyme derived from a vitamin.
C) noncompetitive inhibitor of the enzyme.
D) cofactor necessary for enzyme activity.
E) allosteric activator of the enzyme.
15) When you have a severe fever, what may be a grave consequence if this is not controlled?
A) change in the folding of enzymes
B) removal of the amino acids in active sites
C) binding of enzymes to inappropriate substrates
D) removal of amine groups from your proteins
E) destruction of your enzymes' primary structure
16) Some enzymatic regulation is allosteric. In such cases, which of the following would usually be found?
A) feedback inhibition
B) the need for cofactors
C) an enzyme with more than one subunit
D) cooperativity
E) both activating and inhibitory activity
17) The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction
A) loses electrons and gains energy.
B) gains electrons and loses energy.
C) loses electrons and loses energy.
D) gains electrons and gains energy.
E) neither gains nor loses electrons, but gains or loses energy.
18) The ATP made during glycolysis is generated by
A) chemiosmosis.
B) substrate-level phosphorylation.
C) electron transport.
D) photophosphorylation.
E) oxidation of NADH to NAD+ .
19) During glycolysis, when glucose is catabolized to pyruvate, most of the energy of glucose is
A) retained in the pyruvate.
B) transferred to ADP, forming ATP.
C) transferred directly to ATP.
D) used to phosphorylate fructose to form fructose-6-phosphate.
E) stored in the NADH produced.
20) A molecule that is phosphorylated
A) has a decreased chemical reactivity; it is less likely to provide energy for cellular work.
B) has been reduced as a result of a redox reaction involving the loss of an inorganic phosphate.
C) has an increased chemical reactivity; it is primed to do cellular work.
D) has been oxidized as a result of a redox reaction involving the gain of an inorganic phosphate.
E) has less energy than before its phosphorylation and therefore less energy for cellular work.
21) Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the
removal of a carbon (CO2 ) from one molecule of pyruvate?
A)
B)
C)
D)
E)
oxaloacetate
acetyl CoA
glyceraldehydes-3-phosphate
lactate
citrate
22) How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of
pyruvate?
A) 8
B) 2
C) 10
D) 4
E) 6
23) During aerobic respiration, electrons travel downhill in which sequence?
A) food
NADH
electron transport chain
oxygen
B) glucose
ATP
electron transport chain
NADH
citric acid cycle
ATP
NAD+
C) food
D) food glycolysis
citric acid cycle
NADH
ATP
E) glucose
pyruvate
ATP
oxygen
24) The primary role of oxygen in cellular respiration is to
A) act as an acceptor for electrons and hydrogen, forming water.
B) catalyze the reactions of glycolysis.
C) combine with lactate, forming pyruvate.
D) combine with carbon, forming CO2 .
E) yield energy in the form of ATP as it is passed down the respiratory chain.
25) Energy released by the electron transport chain is used to pump H + ions into which location?
A) mitochondrial outer membrane
B) mitochondrial inner membrane
C) cytosol
D) mitochondrial intermembrane space
E) mitochondrial matrix
26) When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the
intermembrane space, the result is the
A) creation of a proton gradient.
B) formation of ATP.
C) reduction of NAD+ .
D) restoration of the Na+ /K+ balance across the membrane.
E) lowering of pH in the mitochondrial matrix.
27) Which of the following produces the most ATP when glucose (C 6 H12O6 ) is completely oxidized to carbon
dioxide (CO2 ) and water?
A)
B)
C)
D)
E)
oxidative phosphorylation (chemiosmosis)
fermentation
oxidation of pyruvate to acetyl CoA
citric acid cycle
glycolysis
28) Recall that the complete oxidation of a mole of glucose releases 686 kcal of energy ( G = -686 kcal/mol). The
phosphorylation of ADP to form ATP stores approximately 7.3 kcal per mole of ATP. What is the approximate
efficiency of cellular respiration for a "mutant" organism that produces only 29 moles of ATP for every mole of
glucose oxidized, rather than the usual 36-38 moles of ATP?
A) 30%
B) 60%
C) 25%
D) 0.4%
E) 40%
29) Which of the following normally occurs whether or not oxygen (O 2 ) is present?
A)
B)
C)
D)
E)
citric acid cycle
oxidative phosphorylation (chemiosmosis)
glycolysis
fermentation
oxidation of pyruvate to acetyl CoA
30) One function of both alcohol fermentation and lactic acid fermentation is to
A) reduce FAD+ to FADH2 .
B) reduce NAD+ to NADH.
C) reduce FADH2 to FAD+ .
D) oxidize NADH to NAD+.
E) none of the above
31) An organism is discovered that consumes a considerable amount of sugar, yet does not gain much weight
when denied air. Curiously, the consumption of sugar increases as air is removed from the organism's
environment, but the organism seems to thrive even in the absence of air. When returned to normal air, the
organism does fine. Which of the following best describes the organism?
A) It is a normal eukaryotic organism.
B) The organism obviously lacks the citric acid cycle and electron transport chain.
C) It is a facultative anaerobe.
D) It is an anaerobic organism.
E) It must use a molecule other than oxygen to accept electrons from the electron transport chain.
32) Why is glycolysis considered to be one of the first metabolic pathways to have evolved?
A) It relies on chemiosmosis which is a metabolic mechanism present only in the first cells-prokaryotic cells.
B) It is found in prokaryotic cells but not in eukaryotic cells.
C) It requires the presence of membrane-enclosed cell organelles found only in eukaryotic cells.
D) It produces much less ATP than does oxidative phosphorylation.
E) It is found in the cytosol, does not involve oxygen, and is present in most organisms.
33) You have a friend who lost 7 kg (about 15 pounds) of fat on a "low carb" diet. How did the fat leave her body?
A) It was converted to ATP, which weighs much less than fat.
B) It was broken down to amino acids and eliminated from the body.
C) Chemical energy was converted to heat and then released.
D) It was released as CO2 and H2 O.
E) It was converted to urine and eliminated from the body.
34) What is the purpose of beta oxidation in respiration?
A) oxidation of pyruvate
B) breakdown of fatty acids
C) oxidation of glucose
D) feedback regulation
E) control of ATP accumulation
35) If photosynthesizing green algae are provided with CO 2 synthesized with heavy oxygen ( 18O), later analysis
will show that all but one of the following compounds produced by the algae contain the 18O label. That one is
A) PGAL.
B) glucose.
C) O2 .
D) RuBP.
E) PGA.
36) In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary?
A) autotrophs and heterotrophs
B) autotrophs
C) photosynthesizers
D) producers and primary consumers
E) green plants
Use the following information to answer the questions below.
Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different
segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria
congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light.
37) What did Engelmann conclude about the congregation of bacteria in the red and blue areas?
A) Bacteria congregated in these areas due to an increase in the temperature of the red and blue light.
B) Bacteria congregated in these areas due to an increase in the temperature caused by an increase in
photosynthesis.
C) Bacteria are attracted to red and blue light and thus these wavelengths are more reactive than other
wavelengths.
D) Bacteria congregated in these areas because these areas had the most oxygen being released.
E) Bacteria released excess carbon dioxide in these areas.
38) An outcome of this experiment was to help determine
A) the relationship between heterotrophic and autotrophic organisms.
B) the relationship between wavelengths of light and the amount of heat released.
C) the relationship between the concentration of carbon dioxide and the rate of photosynthesis.
D) the relationship between wavelengths of light and the rate of aerobic respiration.
E) the relationship between wavelengths of light and the oxygen released during photosynthesis.
39) If you ran the same experiment without passing light through a prism, what would you predict?
A) The number of bacteria present would increase due to an increase in the carbon dioxide concentration.
B) There would be no difference in results.
C) The number of bacteria would decrease due to a decrease in the temperature of the water.
D) The bacteria would be relatively evenly distributed along the algal filaments.
E) The number of bacteria present would decrease due to an increase in the carbon dioxide concentration.
40) In the thylakoid membranes, what is the main role of the antenna pigment molecules?
A) transfer electrons to ferredoxin and then NADPH
B) concentrate photons within the stroma
C) harvest photons and transfer light energy to the reaction-center chlorophyll
D) split water and release oxygen to the reaction-center chlorophyll
E) synthesize ATP from ADP and Pi
41) Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best
way to detect the lack of photosystem II in these organisms would be
A) to test for liberation of O2 in the light.
B) to test for production of either sucrose or starch.
C) to do experiments to generate an action spectrum.
D) to test for CO2 fixation in the dark.
E) to determine if they have thylakoids in the chloroplasts.
42) Which statement describes the functioning of photosystem II?
A) Light energy excites electrons in the electron transport chain in a photosynthetic unit.
B) The splitting of water yields molecular carbon dioxide as a by-product.
C) The electron vacancies in P680 are filled by electrons derived from water.
D) The excitation is passed along to a molecule of P700 chlorophyll in the photosynthetic unit.
E) The P680 chlorophyll donates a pair of protons to NADPH, which is thus converted to NADP +.
43) In a plant cell, where are the ATP synthase complexes located?
A) inner mitochondrial membrane
B) plasma membrane
C) thylakoid membrane
D) A and C
E) A, B, and C
44) The splitting of carbon dioxide to form oxygen gas and carbon compounds occurs during
A) photorespiration.
B) both photosynthesis and respiration.
C) respiration.
D) neither photosynthesis nor respiration.
E) photosynthesis.
For the following questions, compare the light reactions with the Calvin cycle of photosynthesis in plants.
45) Produces molecular oxygen (O2 )
A)
B)
C)
D)
E)
the Calvin cycle alone
light reactions alone
both the light reactions and the Calvin cycle
occurs in the chloroplast but is not part of photosynthesis
neither the light reactions nor the Calvin cycle
46) Requires CO2
A) both the light reactions and the Calvin cycle
B) occurs in the chloroplast but is not part of photosynthesis
C) the Calvin cycle alone
D) light reactions alone
E) neither the light reactions nor the Calvin cycle
47) The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a
particular plant cell. Which, if any, relationship would you expect to find?
A) The pH of the thylakoid space is higher than that anywhere else in the cell.
B) There is no consistent relationship.
C) The pH within the thylakoid is less than that of the stroma.
D) The pH of the stroma is higher than that of the thylakoid space but lower than that of the cytosol.
E) The pH of the stroma is higher than that of the other two measurements.
48) In an experiment studying photosynthesis performed during the day, you provide a plant with radioactive
carbon (14C) dioxide as a metabolic tracer. The 14C is incorporated first into oxaloacetate. The plant is best
characterized as a
A) CAM plant.
B) heterotroph.
C) chemoautotroph.
D) C3 plant.
E) C4 plant.
49) CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they
A) fix CO2 into organic acids during the night.
B) use photosystems I and II at night.
C) use the enzyme phosphofructokinase, which outcompetes rubisco for CO 2 .
D) fix CO2 into sugars in the bundle-sheath cells.
E) fix CO2 into pyruvate in the mesophyll cells.
50) The alternative pathways of photosynthesis using the C4 or CAM systems are said to be compromises. Why?
A) Each one minimizes both water loss and rate of photosynthesis.
B) C4 compromises on water loss and CAM compromises on photorespiration.
C) CAM plants allow more water loss, while C4 plants allow less CO 2 into the plant.
D) C4 plants allow less water loss but Cam plants but allow more water loss.
E) Each one both minimizes photorespiration and optimizes the Calvin cycle.