Download 008 Chapter 08 Metabolism: Energy Enzymes and Regulation 1

008 Chapter 08 Metabolism: Energy Enzymes and
Regulation
1. The amount of heat energy needed to raise 1 gram of water from 14.5C to 15.5C is called a(n)
A. joule.
B. calorie.
C. erg.
D. thermal unit.
2. Which of the following is used as an electron carrier by living organisms?
A. NAD+
B. NADP+
C. ubiquinone
D. all of the choices
3. Which of the following is not true about enzymes?
A. Enzymes are catalysts that speed up reactions.
B. Enzymes are proteins that can be denatured by changes in pH or temperature.
C. Enzymes are highly specific for the substrates they react with and catalyze only one or a limited set of
possible reactions with those substrates.
D. all of the choices
4. The energy required to bring the substrates of a reaction together in the correct way to reach the
transition state is called
A. free energy.
B. activation energy.
C. enthalpy.
D. entropy.
5. Enzymes catalyze a reaction by
A. decreasing the amount of energy released by the reaction.
B. increasing the amount of energy released by the reaction.
C. decreasing the activation energy of the reaction.
D. increasing the activation energy of the reaction.
6. Enzymes function as catalysts by
A. bringing the substrates together at the active site, in effect concentrating them.
B. bringing the substrates together at the active site correctly oriented for the reaction.
C. bringing the substrates together at the active site, in effect concentrating them and bringing the
substrates together at the active site correctly oriented for the reaction.
D. none of the choices
7. For the reaction A + B C + D, the equilibrium constant (Keq) is defined as
A. [A][B]/[C][D].
B. [C][D]/[A][B].
C. [A][D]/[B][C].
D. [B][C]/[A][D].
8. The __________ is the electron donor in a redox reaction.
A. reductant
B. oxidant
C. enzyme
D. product
9. The __________ is the electron acceptor in a redox reaction.
A. reductant
B. oxidant
C. enzyme
D. product
10. The __________ law of thermodynamics states that energy can be neither created nor destroyed.
A. first
B. second
C. third
D. fourth
11. The __________ law of thermodynamics states that physical and chemical processes occur in such a
way that randomness (disorder) increases to a maximum.
A. first
B. second
C. third
D. fourth
12. __________ is a measure of the randomness or disorder of a system.
A. Entropy
B. Enthalpy
C. Free energy
D. Synergy
13. The change in __________ is the amount of energy in a system that is available to do work.
A. entropy
B. enthalpy
C. free energy
D. synergy
14. __________ is the total energy change that accompanies a chemical reaction.
A. Entropy
B. Enthalpy
C. Free energy
D. Synergy
15. The free energy change that accompanies a chemical transformation is usually expressed in units of
______________ by biologists.
A. joules
B. calories
C. ergs
D. electron volts
16. An chemical reaction that requires an input of energy in order to proceed is __________.
A. exergonic
B. endergonic
C. impossible
D. one of the choices
17. A reaction that releases energy is __________.
A. exergonic
B. endergonic
C. impossible
D. none of the choices
18. A(n) _______________ increases the rate of a reaction without being permanently altered by the
reaction.
A. catalyzer
B. catalyst
C. enzyme
D. rate increaser
19. If all available enzyme molecules are binding substrate and converting it to produce as rapidly as
possible, the reaction is said to be proceeding at __________ velocity.
A. terminal
B. maximal
C. optimal
D. infinite
20. If an enzyme consists of a protein component and a non-protein component, the protein component is
referred as the
A. apoenzyme.
B. coenzyme.
C. holoenzyme.
D. prosthetic group.
21. The nonprotein component of an enzyme that is firmly attached to the protein is called a(n)
A. apoenzyme.
B. coenzyme.
C. holoenzyme.
D. prosthetic group.
22. A nonprotein component of an enzyme that is loosely attached to the protein component is referred to
as a(n)
A. apoenzyme.
B. coenzyme.
C. holoenzyme.
D. prosthetic group.
23. The standard reduction potential of a redox reaction is a measure of the tendency of the __________
to __________ electrons.
A. reductant; gain
B. reductant; lose
C. oxidant; gain
D. oxidant; lose
24. A complete enzyme that consists of a protein component and a nonprotein component is called a(n)
A. apoenzyme.
B. heteroenzyme.
C. holoenzyme.
D. multienzyme.
25. Competitive inhibition can be overcome by adding excess
A. inhibitor.
B. substrate.
C. enzyme.
D. none of the choices.
26. The substrate of an enzyme binds at the
A. affinity site.
B. active site.
C. determinative site.
D. reaction site.
27. Which of the following represents work normally done by cells?
A. synthesis of complex molecules
B. nutrient uptake and waste elimination
C. internal and external movement
D. all of the choices
28. The most specific term usually used to describe a substance in a biological system that increases the
rate of a reaction without being permanently changed by the reaction is a(n)
A. catalyzer.
B. catalyst.
C. enzyme.
D. rate increaser.
29. Enzymes are usually named based on
A. the substrates they act on.
B. their molecular structure.
C. the type of reaction they catalyze.
D. all of the choices.
E. the substrates they act on and the type of reaction they catalyze.
30. Electron transport molecules that only transfer electrons include
A. ubiquinone.
B. NADP.
C. FAD.
D. ferredoxin.
31. When the end product of a pathway inhibits catalysis of the first step of that pathway, this
phenomenon is called
A. reversible covalent modification.
B. feedback inhibition.
C. metabolic channeling.
D. non-competitive inhibition.
32. Key features of ADP include which of the following?
A. DG for hydrolysis of its terminal phosphate is more negative than any other molecule in the cell.
B. It can function as a phospho donor and a phospho acceptor.
C. It is produced only in mitochondria.
D. DG for hydrolysis of the terminal phosphate is more negative under aerobic conditions.
33. Which of the following is a reason for metabolic regulation?
A. maintain cell components at appropriate levels
B. conserve materials
C. ensure efficient use energy stores
D. all of the choices
34. In metabolic channeling, the regulation of metabolic pathways is controlled by the __________ of
metabolites and enzymes involved in the pathway.
A. amount
B. location
C. activity
D. all of the choices
35. Enzyme activity can be controlled by
A. allosteric regulation.
B. covalent modification.
C. feedback (end product) inhibition.
D. all of the choices
36. In allosteric regulation, effector molecules usually bind
A. reversibly and covalently.
B. irreversibly and covalently.
C. reversibly and noncovalently.
D. irreversibly and noncovalently.
37. In a branched pathway with many end products, an abundance of one of the end products will usually
inhibit
A. the first step in the set of pathways.
B. the first committed step in the branch of the pathway leading to the production of that particular
product.
C. the last step before the branch leading to the production of that particular end product.
D. the last step in the production of that particular product.
38. Metabolic channeling involves the localization of __________ in different parts of a cell in order to
influence the activity of metabolic pathways.
A. activators
B. repressors
C. substrates and enzymes
D. inhibitors
39. Enzymes increase the rate of a reaction by increasing molecular motion, thereby providing kinetic
energy to drive the reaction.
True False
40. The flow of carbon and energy in an ecosystem are intimately related. Light energy is trapped by
photoautotrophs, and some of this flows to chemoheterotrophs when they use the former for nutrients.
The carbon dioxide produced during respiration can be incorporated into complex organic molecules
during photosynthesis.
True False
41. Some endergonic reactions can be made to proceed forward if they are coupled to hydrolysis of one or
more of the phosphates of ATP.
True False
42. The equilibrium constant for a redox reaction is called the standard reduction potential.
True False
43. The numerical value of the free energy change indicates how fast a reaction will reach equilibrium.
True False
44. One of the components used during photosynthetic electron transport is ferredoxin, a nonheme iron
protein.
True False
45. Enzymes increase the rate of a reaction but do not alter equilibrium constants.
True False
46. When the amount of enzyme present is held constant, the rate of a reaction will continue to increase as
long as the substrate concentration increases.
True False
47. Enzyme activity can be greatly affected by the pH and the temperature of the environment in which
the enzyme must function.
True False
48. The rate at which a reaction proceeds is limited primarily by the rate at which the transition state is
formed.
True False
49. The Michaelis constant (Km) of an enzyme is the substrate concentration that produces maximum
velocity.
True False
50. Each enzyme normally has specific pH and temperature optima at which they function best.
True False
51. A reaction will occur spontaneously if the free energy of the system increases during the reaction.
True False
52. The electron transport chain is based on the principle that redox couples with more positive reduction
potentials will donate electrons to couples with more negative potentials.
True False
53. Energy can be redistributed within a collection of matter (called a system) or can be redistributed
between the system and its surroundings.
True False
54. Isoenzymes are different enzymes that catalyze the same reaction but can be regulated independently
of one another.
True False
55. __________ is the science that analyzes energy changes in a collection of matter.
56. A reaction in which the forward rate is equal to the reverse rate is said to be at __________.
57. A complex formed during a reaction that resembles both the substrates and the products is called the
__________ state complex.
58. The __________ __________ is the substrate concentration needed for an enzyme to achieve half
maximal velocity.
59. In thermodynamic studies, energy changes are analyzed in a collection of matter called a __________.
All other matter in the universe is called the __________.
60. Cells must efficiently transfer energy from their energy-trapping systems to the systems actually
carrying out work and also use various metabolic processes to replace the energy used in doing work.
This is called the __________.
61. In order for the cell to be able to input energy into necessary endergonic reactions, energy-generating
processes such as photosynthesis, fermentation, and respiration are used to produce __________.
62. The reacting molecules in an enzyme-catalyzed reaction are called __________.
63. The molecules formed by an enzyme-catalyzed reaction are called __________.
64. A molecule that binds noncovalently to an enzyme at the active site and thereby prevents a substrate
from binding and reacting is a(n) __________ inhibitor.
65. A molecule that binds to an enzyme at a location other than the active site and thereby alters the
enzyme's shape, making it inactive or less active is a(n) __________ inhibitor.
66. Disruption of an enzyme's structure with loss of activity caused by extremes of pH, temperature, or
other factors is called _________.
009 Chapter 09 Metabolism: Energy Release and
Conservation
Student: ___________________________________________________________________________
1. The Strickland reaction
A. is an alternative glycolytic pathway.
B. is a fermentation reaction in which one amino acid is oxidized and a second amino acid is reduced.
C. is used to oxidize nucleotides.
D. results in production of high concentrations of intracellular glycerol, which can be used to
counterbalance osmotic pressure.
2. The most common pathway for conversion of glucose to pyruvate is
A. Entner-Doudoroff.
B. Pentose phosphate.
C. Embden-Meyerhoff.
D. mixed acid fermentation.
3. The synthesis of ATP from ADP and Pi, when coupled with an exergonic chemical reaction is called
__________ phosphorylation.
A. chemiosmotic
B. oxidative
C. substrate-level
D. conformational change
4. The pentose phosphate pathway provides
A. ATP.
B. NADPH.
C. four- and five-carbon sugars for amino acid and nucleic acid synthesis.
D. all of the choices
5. How many molecules of ATP are needed to reduce one molecule of carbon dioxide to carbohydrate?
A. 2
B. 3
C. 4
D. 10-12
6. How many molecules of NADPH are needed to reduce one molecule of carbon dioxide to
carbohydrate?
A. 2
B. 3
C. 4
D. 10-12
7. How many quanta of light are needed to reduce one molecule of carbon dioxide to carbohydrate?
A. 2
B. 3
C. 4
D. 10-12
8. The major function(s) of the TCA cycle is(are)
A. energy production.
B. provision of carbon skeletons for biosynthesis of cell components.
C. direct oxidation of 4 and 5 carbon sugars during anaerobic growth.
D. energy production and provision of carbon skeletons for biosynthesis of cell components.
9. The number of ATP molecules generated per atom of oxygen that is reduced when electrons are passed
from NADH or reduced FAD (FADH) to dioxygen is called the
A. utilization ratio.
B. energy yield.
C. P/O ratio.
D. phosphorylation coefficient.
10. In higher eucaryotes, most aerobically generated ATP is produced by
A. glycolysis.
B. the TCA cycle.
C. a membrane bound proton translocating ATP synthase.
D. all of these generate equal amounts of ATP.
11. Mitochondrial electron transport takes place
A. on the outer mitochondrial membrane.
B. on the inner mitochondrial membrane.
C. in the fluid matrix of the mitochondria.
D. on the outer mitochondrial membrane and on the inner mitochondrial membrane
12. Photosynthetic electron transport in cyanobacteria takes place
A. on the plasma membrane.
B. in the chloroplast.
C. in the cytoplasm.
D. on the thylakoid membranes.
13. The sum total of all chemical reactions occurring in a cell is called
A. anabolism.
B. catabolism.
C. metabolism.
D. none of the choices
14. The breakdown of larger, more complex molecules into smaller, simpler ones with the release and
trapping of some energy contained within those molecules is called
A. anabolism.
B. catabolism.
C. metabolism.
D. none of the choices
15. The synthesis of complex molecules from simpler ones with the input of energy is called
A. anabolism.
B. catabolism.
C. metabolism.
D. none of these
16. Production of ATP using the energy liberated when electrons from reduced chemical bonds are pass
through the electron transport system is generally referred to as __________.
A. chemiosmotic
B. respiration
C. substrate-level
D. conformational change
17. In the process of __________, ATP is synthesized when excited electrons from chlorophyll P700 pass
through a series of electron carriers then return to chlorophyll P700.
A. photosynthesis
B. cyclic photophosphorylation
C. acyclic photophosphorylation
D. noncyclic photophosphorylation
18. In the process of noncyclic photophosphorylation
A. water is split to form oxygen gas.
B. electrons from water flow through electron transport chains resulting in synthesis of ATP and NADPH.
C. photosystems I and II are both required.
D. all of the choices
19. The theoretical maximum net gain of ATP per molecule of glucose metabolized aerobically in
eucaryotes is
A. 2.
B. 36.
C. 38.
D. 85.
20. The net gain of ATP per molecule of glucose metabolized pyruvate using Entner-Doudoroff pathway
is
A. 4.
B. 2.
C. 1.
D. 0.
21. The net gain of ATP per molecule of glucose metabolized anaerobically in eucaryotes is
A. 2.
B. 36.
C. 38.
D. 85.
22. The net gain of ATP per molecule of glucose metabolized anaerobically via the Embden-Meyerhoff
pathway in procaryotes is
A. 2.
B. 36.
C. 38.
D. 85.
23. In the TCA cycle, two carbons in the form of __________ are added to oxaloacetate at the start of the
cycle.
A. acetyl-CoA
B. ethanol
C. carbon dioxide
D. methanol
24. In the TCA cycle, two carbons are removed from citric acid in the form of __________, thereby
regenerating oxaloacetate to complete the cycle.
A. acetyl-CoA
B. ethanol
C. carbon dioxide
D. methanol
25. In aerobic conditions, it takes __________ sugar to produce the same amount of ATP when compared
to anaerobic conditions.
A. more
B. less
C. the same amount of
26. Which of the following can be used as electron acceptors during anaerobic respiration?
A. nitrate
B. sulfate
C. carbon dioxide
D. all of the choices
27. Fatty acids are metabolized by the __________ pathway.
A. alpha-oxidation
B. beta-oxidation
C. gamma-oxidation
D. delta-oxidation
28. During breakdown of fatty acids, carbons are removed __________ at a time as __________.
A. one; carbon dioxide
B. one; methane
C. two; acetyl-CoA
D. two; ethanol
29. Amino acids are processed first by the removal of the amino group through
A. deamination.
B. transamination.
C. phosphorolytic cleavage.
D. deamination or transamination
30. Which of the following may be used as sources of energy by chemolithotrophs?
A. hydrogen gas
B. ammonia
C. hydrogen sulfide
D. all of the choices
31. Which of the following is NOT true regarding ATP synthases?
A. They require proton motive force to make ATP.
B. They span the inner membrane of mitochondria.
C. The proton flow is outward during ATP synthesis.
D. The subunits of ATP synthase undergo conformational changes during ATP production.
32. Differences between mitochondrial and E. coli electron transport chains include the following:
A. The E. coli chain is branched and contains a different array of cytochromes.
B. The fundamental principles on which they operate are different.
C. Higher P/O values are observed in E. coli.
D. The electron transport change does not involve membranes in E. coli.
33. Oxygen is always required for the regeneration of NAD from NADH.
True False
34. Reduction of nitrate to nitrite by Paracoccus denitrificans is an example of anaerobic respiration.
True False
35. Procaryotes may use several different terminal oxidases for the electron transport system.
True False
36. In the process of fermentation an organic substrate, such as glucose, is reduced and an intermediate of
the pathway, such as pyruvate, is oxidized.
True False
37. An organism may use glycolysis and the pentose phosphate pathway simultaneously.
True False
38. In addition to being used in the making of ATP, proton motive force is used directly to power the
rotation of bacterial flagella.
True False
39. Although most metabolic reactions are freely reversible, a few irreversible catabolic steps are
bypassed during biosynthesis with special enzymes that catalyze the reverse reaction in order to allow for
independent regulation of catabolic and anabolic pathways.
True False
40. Photosynthetic organisms serve as the base for most food chains in the biosphere.
True False
41. The electron transport systems in eucaryotes and procaryotes use different electron carriers.
True False
42. Some aerobic bacteria lack the Entner-Doudoroff and Embden-Meyerhoff pathways and instead use
the pentose phosphate pathway for glycolysis.
True False
43. Very few gram positive bacteria utilize the Entner-Doudoroff glycolytic pathway.
True False
44. Metabolic pathways can be either catabolic or anabolic but not both.
True False
45. All eucaryotic photosynthesizers are oxygenic.
True False
46. All procaryotic photosynthesizers are anoxygenic.
True False
47. Fermentation involves the use of pyruvate and/or other organic molecules as electron acceptors.
True False
48. Bacterial electron transport chains may be comprised of fewer components and have lower P/O ratios
than mitochondrial transport chains.
True False
49. __________ pathways are those that function both catabolically and anabolically.
50. The most commonly accepted hypothesis for the production of ATP that results from electron
transport system is called the __________ hypothesis.
51. When cells of a facultative anaerobe such as E. coli are growing under anaerobic conditions and using
nitrate as the terminal electron acceptor, ______________ nitrate reduction is occurring.
52. Organisms that directly reduce almost all of their pyruvate to lactate are called __________
fermenters.
53. Organisms that form lactate ethanol and CO2 as end products of glucose metabolism are called
__________ fermenters.
54. Disaccharides and polysaccharides can be processed as nutrients after first being cleaved to
monosaccharides by either __________ or __________.
55. Proteins are catabolized by hydrolytic cleavage to amino acids by the action of enzymes called
__________.
56. The hypothesis that proton motive force drives ATP synthesis is called the __________ hypothesis.
57. When mitochondria pass electrons donated by NADH through the electron transport chain to
molecular oxygen, a theoretical maximum of __________ molecules of ATP can be made per oxygen
molecule reduced.
58. __________ is used as the terminal electron acceptor for oxidizing NADH to NAD in aerobic
respiration, but molecules other than oxygen are used as the terminal electron acceptors in __________
respiration.
59. The mitochondrial electron transport system is arranged into four complexes of carriers connected to
each other by __________ and __________.
60. In addition to their place in various food chains, photosynthetic organisms are responsible for
replenishing our supply of __________.
010 Chapter 10 Metabolism: The Use of Energy in
Biosynthesis
1. Large numbers of small monomeric molecules join together to form large molecules that are known as:
A. multimers.
B. polymolecules.
C. macromolecules.
D. maximolecules.
2. Phosphorous is usually assimilated by microorganisms as
A. polyphosphate (volutin).
B. phosphene.
C. elemental phosphate (Po).
D. phosphate.
3. Microorganisms assimilate large amounts of all of the following except __________ into organic
molecules.
A. nitrogen
B. phosphorus
C. sodium
D. sulfur
4. __________ reactions are used to replace TCA cycle intermediates that have been used to provide
carbon skeletons for amino acid biosynthesis.
A. Amphibolic
B. Anaplerotic
C. Anabolic
D. Catabolic
5. The series of enzymatic steps that fixes carbon dioxide into carbohydrate is called the ______.
A. Pentose phosphate pathway
B. Embden-Meyerhoff pathway
C. Calvin cycle
D. Entner-Doudoroff pathway
6. The synthesis of glucose from non-carbohydrate precursors is called
A. glycolysis.
B. glutamine synthase.
C. gluconeogenesis.
D. none of the choices
7. Nitrogen fixation depends on the enzyme nitrogenase which is produced by some
A. Archaea.
B. bacterial.
C. eucaryotes.
D. bacteria and Archaea but no eucaryotes.
E. fungi and bacteria.
8. The reduction of atmospheric nitrogen to ammonia is called
A. ammonification.
B. nitrification.
C. denitrification.
D. nitrogen fixation.
9. In order to synthesize new peptidoglycan for bacterial cell walls, the existing walls must be partially
digested by __________ to provide acceptor ends for the new synthesis.
A. lysozyme
B. autolysins
C. autozymogens
D. peptidoglycolysins
10. There are __________ common amino acids used to synthesize proteins.
A. 20
B. 61
C. 64
D. 25
11. __________ is the carrier molecule required to transport peptidoglycan subunits to the location where
they will be incorporated into the growing bacterial cell wall.
A. Bactoprenol
B. UDP glucose
C. Acyl carrier protein
D. Malonyl-CoA
12. The photosynthetic production of one molecule of glucose requires __________ molecule(s) of ATP.
A. 6
B. 12
C. 18
D. 24
13. The photosynthetic production of one molecule of glucose requires __________ molecule(s) of
NADPH.
A. 6
B. 12
C. 18
D. 24
14. Photoautotrophs use light energy directly for
A. the production of ATP and NADPH.
B. the reduction of carbon dioxide to carbohydrate.
C. both the production of ATP and NADPH and the reduction of carbon dioxide to carbohydrate.
D. neither the production of ATP and NADPH nor the reduction of carbon dioxide to carbohydrate.
15. Many microbes use pyruvate carboxylase or phosphoenolpyruvate carboxylase to
A. to synthesize amino acids.
B. to synthesize glucose.
C. to synthesize oxaloacetate.
D. to synthesize acetyl-CoA.
16. The reduction of sulfate for use in the production of compounds such as cysteine is called
__________ sulfate reduction.
A. assimilatory
B. dissimilatory
C. amodulatory
D. demodulatory
17. The reduction of sulfate as a terminal electron acceptor during anaerobic respiration is called
__________ sulfate reduction.
A. assimilatory
B. dissimilatory
C. amodulatory
D. demodulatory
18. Most microorganisms assimilate nitrogen as
A. ammonia.
B. hydrazine.
C. nitrate.
D. ammonia or nitrate
19. __________ are heterocyclic nitrogenous bases with several double bonds and pronounced aromatic
properties.
A. Purines
B. Quinones
C. Amino acids
D. Fatty acids
20. Assemblies of macromolecules are referred to as __________ complexes.
A. ultramolecular
B. supramolecular
C. metamolecular
D. maximolecular
21. A purine or pyrimidine that is attached to a sugar, either ribose or deoxyribose, is called a
A. nucleotide.
B. nucleoside.
C. nitrogenous base.
D. nucleic acid.
22. A purine or pyrimidine that is attached to a sugar, either ribose or deoxyribose, to which is attached
one or more phosphate groups is called a:
A. nucleotide.
B. nucleoside.
C. nitrogenous base.
D. nucleic acid.
23. Purines and pyrimidines are precursors for synthesis of
A. fatty acids.
B. nucleic acids.
C. proteins.
D. peptidoglycan.
24. In addition to nitrogen, which of the following can be reduced by the enzyme nitrogenase?
A. acetylene
B. ammonia
C. sulfate
D. chloride
25. The major reductive amination pathway for incorporation of nitrogen into amino acids initially
involves the production of
A. tryptophan.
B. cysteine.
C. arginine.
D. glutamate.
26. Unsaturated fatty acids are those containing __________ carbon-carbon double bond(s).
A. only one
B. exactly two
C. one or more
D. two or more
27. Which of the following do(es) not contribute to the construction of membrane phospholipids?
A. glycolysis
B. fatty acid biosynthesis
C. amino acid biosynthesis
D. nucleotide biosynthesis
28. Synthesis of complex molecules from simpler ones with the input of energy is called
A. metabolism.
B. anabolism.
C. catabolism.
D. amphibolism.
29. In order to form a single molecule of glucose, it takes __________ turns through the reactions of the
Calvin cycle.
A. 3
B. 4
C. 6
D. 12
30. Assimilation of organic phosphates from the surroundings uses enzymes known as
A. phosphorylases.
B. phosphatases.
C. phosphosynthetases.
D. phosphoisomerases.
31. Which of the following is not a phase of the Calvin Cycle?
A. carboxylation phase
B. oxidation phase
C. reduction phase
D. regeneration phase
32. Which of the following statements is true about growth-zones for peptidoglycan formation?
A. Cocci have only one or two growth zones, usually at the site of septum formation.
B. Rod-shaped organisms have multiple growth zones along the cylindrical portion of the bacterium as
well as at the site of septum formation.
C. Cocci have only one or two growth zones, usually at the site of septum formation and Rod-shaped
organisms have multiple growth zones along the cylindrical portion of the bacterium as well as at the site
of septum formation
D. neither Cocci have only one or two growth zones, usually at the site of septum formation nor Rodshaped organisms have multiple growth zones along the cylindrical portion of the bacterium as well as at
the site of septum formation
33. Which of the following is a source of carbon skeletons that are used in the synthesis of amino acids?
A. Acetyl-CoA
B. TCA cycle intermediates
C. glycolysis intermediates
D. all of the choices
34. Which of the following is not generally true about fatty acids produced by microorganisms?
A. Fatty acids are monocarboxylic acids.
B. Fatty acids have long alkyl chains.
C. Gram-positive bacteria often make cyclopropane fatty acids.
D. All of these are generally true about fatty acids.
35. Which of the following cofactors is used in the synthesis of purines and pyrimidines?
A. acetyl-CoA
B. cytidine diphosphate
C. folic acid
D. glutathione
36. Which of the following is true about the synthesis of macromolecules from monomeric subunits?
A. It saves genetic storage capacity.
B. It saves biosynthetic raw materials.
C. It saves energy.
D. all of the choices
37. Symbiotic nitrogen fixation can consume up to __________% of the ATP generated by the host
plant.
A. 5
B. 20
C. 30
D. 50
38. Which pathway(s) is used to fix carbon dioxide?
A. glycolysis
B. reductive tricarboxylic pathway
C. Entner-Doudoroff
D. pentose phosphate pathway
39. Which pathway(s) are used by eucaryotic microorganisms to fix carbon dioxide?
A. Calvin-Benson cycle
B. reductive tricarboxylic pathway
C. Entner-Doudoroff
D. none of the choices
40. The process of carbon dioxide fixation refers to
A. release of carbon dioxide during catabolic reactions.
B. reduction of carbon dioxide and incorporation into organic molecules that are assimilated.
C. release of carbon dioxide during anabolic reactions.
D. reaction of carbon dioxide with water to form carbonic acid.
41. One of the ways in which cells independently regulate anabolic and catabolic pathways is by the use
of different cofactors for similar reactions.
True False
42. The biosynthesis of some amino acids require the use of some TCA cycle intermediates as carbon
skeletons.
True False
43. Bacteria can synthesize unsaturated fatty acids only under anaerobic conditions.
True False
44. Once they have been synthesized, bacterial components will continue to exist until the cell is
destroyed.
True False
45. Autotrophs are the only organisms that can incorporate (fix) carbon dioxide into biomolecules.
True False
46. The use of compartmentation for the simultaneous but independent regulation of anabolic and
catabolic pathways occurs generally in eucaryotes but not in procaryotes.
True False
47. In the biosynthesis of nucleotides, pyrimidines are assembled starting with ribose-5-phosphate while
ribose-5-phosphate is added after synthesis of the nitrogenous base for purines.
True False
48. In cocci, peptidoglycan synthesis occurs at one or, at most, a few sites with the principal growth zone
occurring at the site of septum formation.
True False
49. In bacilli, peptidoglycan synthesis occurs at the site of septum formation and at multiple growth sites
scattered along the cylindrical portion of the rod so that growth is diffusely distributed.
True False
50. The rate of biosynthesis is much slower than the rate of breakdown.
True False
51. Many enzyme catalyzed reactions are freely reversible; however, some key steps require separate
enzymes for the reverse step in order to provide for independent regulation of anabolic and catabolic
pathways.
True False
52. Nitrogen fixation is used to store energy by ATP formation.
True False
53. Because peptidoglycan lies outside the plasma membrane, all steps in the complex synthesis process
of this molecule takes place outside the cell.
True False
54. Although most autotrophic microorganisms fix carbon dioxide using the Calvin-Benson cycle, this
pathway is absent in the Archaea.
True False
55. Different proteins have different amino acid __________.
56. Cells save energy and materials by using many of the same enzymes for both __________ and
__________.
57. Eucaryotic cells compartmentalize some anabolic and catabolic pathways so that these pathways can
be operate ______________ .
58. Large structures (e.g., ribosomes) form spontaneously from their macromolecular components by a
process known as __________.
59. In the synthesis of amino acids the addition of the amino nitrogen usually occurs __________ the
synthesis of the carbon skeletons.
60. Unsaturated fatty acids are those containing carbon-carbon ________bonds.
61. Assimilatory sulfate reduction involves the production of ________ which is then utilized to make
cysteine.