Chapter 5 Microbial Metabolism My Nursing Test Banks

Microbiology: An Introduction, 12e (Tortora)

Chapter 5   Microbial Metabolism

5.1   Multiple-Choice Questions

1) Which of the following compounds is NOT an enzyme?

A) dehydrogenase

B) cellulase

C) coenzyme A

D) -galactosidase

E) sucrase

Answer:  C

Section:  5.2

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.3

2) Figure 5.1

Which compound is being reduced in the reaction shown in Figure 5.1?

A) isocitric acid and -ketoglutaric acid

B) -ketoglutaric acid and NAD+

C) NAD+

D) NADH

E) NADH and isocitric acid

Answer:  C

Section:  5.3

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.8

Global Outcome:  3

3) Which organism is NOT correctly matched to its energy source?

A) photoheterotroph light

B) photoautotroph CO2

C) chemoautotroph Fe2+

D) chemoheterotroph glucose

E) chemoautotroph-NH3

Answer:  B

Section:  5.9

Blooms Taxonomy:  Analysis

ASMcue Outcome:  3.1

Learning Outcome:  5.23

Global Outcome:  2

4) Which of the following statements about anaerobic respiration is FALSE?

A) It yields lower amounts of ATP when compared to aerobic respiration.

B) The complete Krebs cycle is utilized.

C) It involves the reduction of an organic final electron acceptor.

D) It generates ATP.

E) It requires cytochromes.

Answer:  C

Section:  5.4

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  3.1

Learning Outcome:  5.15

5) Figure 5.2

What type of reaction is in Figure 5.2?

A) decarboxylation

B) transamination

C) dehydrogenation

D) oxidation

E) reduction

Answer:  B

Section:  5.10

Blooms Taxonomy:  Analysis

Learning Outcome:  5.24

Global Outcome:  2

6) What is the fate of pyruvic acid in an organism that uses aerobic respiration?

A) It is reduced to lactic acid.

B) It reacts with oxaloacetate to form citrate.

C) It is oxidized in the electron transport chain.

D) It is catabolized in glycolysis.

E) It is converted into acetyl CoA.

Answer:  E

Section:  5.4

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.15

7) Figure 5.3

How would a noncompetitive inhibitor interfere with a reaction involving the enzyme shown in Figure 5.3?

A) It would bind to a.

B) It would bind to b.

C) It would bind to c.

D) It would bind to d.

E) The answer cannot be determined based on the information provided.

Answer:  B

Section:  5.2

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.6

8) Figure 5.4

How is ATP generated in the reaction shown in Figure 5.4?

A) glycolysis

B) fermentation

C) photophosphorylation

D) oxidative phosphorylation

E) substrate-level phosphorylation

Answer:  E

Section:  5.3

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.9

Global Outcome:  2

9) Fatty acids are oxidized in

A) the Krebs cycle.

B) the electron transport chain.

C) glycolysis.

D) the pentose phosphate pathway.

E) the Entner-Doudoroff pathway.

Answer:  A

Section:  5.5

Blooms Taxonomy:  Knowledge

ASMcue Outcome:  3.1; 6.3

Learning Outcome:  5.17

10) Figure 5.5

Which of the graphs in Figure 5.5 best illustrates the activity of an enzyme that is saturated with substrate?

A) a

B) b

C) c

D) d

E) e

Answer:  C

Section:  5.2

Blooms Taxonomy:  Analysis

ASMcue Outcome:  7.2

Learning Outcome:  5.5

Global Outcome:  3

11) Which of the following is the best definition of oxidative phosphorylation?

A) Electrons are passed through a series of carriers to O2.

B) A proton gradient allows hydrogen ions to flow back into the cells through transmembrane protein channels, releasing energy that is used to generate ATP.

C) ATP is directly transferred from a substrate to ADP.

D) Electrons are passed through a series of carriers to an organic compound.

Answer:  B

Section:  5.3

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.9

12) Which of the following statements about substrate-level phosphorylation is FALSE?

A) It involves the direct transfer of a high-energy phosphate group from an intermediate metabolic compound to ADP.

B) No final electron acceptor is required.

C) It occurs in glycolysis.

D) The oxidation of intermediate metabolic compounds releases energy that is used to generate ATP.

E) It occurs to a lesser degree in the Krebs cycle than in glycolysis.

Answer:  D

Section:  5.3

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.9

13) Which of the following statements about photophosphorylation is FALSE?

A) Light liberates an electron from chlorophyll.

B) The oxidation of carrier molecules releases energy.

C) Energy from oxidation reactions is used to generate ATP from ADP.

D) It requires CO2.

E) It occurs in photosynthesizing cells.

Answer:  D

Section:  5.3

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  3.1

Learning Outcome:  5.9

14) A strictly fermentative bacterium produces energy

A) by glycolysis only.

B) by aerobic respiration only.

C) by fermentation or aerobic respiration.

D) only in the absence of oxygen.

E) only in the presence of oxygen.

Answer:  A

Section:  5.4

Blooms Taxonomy:  Knowledge

ASMcue Outcome:  3.1

Learning Outcome:  5.16

15) The advantage of the pentose phosphate pathway is that it produces all of the following EXCEPT

A) precursors for nucleic acids.

B) precursors for the synthesis of glucose.

C) three ATPs.

D) NADPH.

E) precursors for the synthesis of amino acids.

Answer:  C

Section:  5.4

Blooms Taxonomy:  Knowledge

ASMcue Outcome:  3.1

Learning Outcome:  5.12

16) Which biochemical process is NOT used during glycolysis?

A) substrate-level phosphorylation

B) oxidation-reduction

C) carbohydrate catabolism

D) beta oxidation

E) enzymatic reactions

Answer:  D

Section:  5.5

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.17

Global Outcome:  7

17) In noncyclic photophosphorylation, O2 is released from

A) CO2.

B) H2O.

C) C6H12O6.

D) sunlight.

E) chlorophyll.

Answer:  B

Section:  5.7

Blooms Taxonomy:  Knowledge

ASMcue Outcome:  3.1

Learning Outcome:  5.19

18) Which of the following is the best definition of fermentation?

A) the partial reduction of glucose to pyruvic acid

B) the partial oxidation of glucose with organic molecules serving as electron acceptors

C) the complete catabolism of glucose to CO2 and H2O

D) the production of energy by oxidative-level phosphorylation

E) the production of energy by both substrate and oxidative phosphorylation

Answer:  B

Section:  5.4

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.16

19) Which of the following is NOT necessary for respiration?

A) cytochromes

B) flavoproteins

C) a source of electrons

D) oxygen

E) quinones

Answer:  D

Section:  5.4

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  3.1

Learning Outcome:  5.15

20) Which one of the following would you predict is an allosteric inhibitor of the Krebs cycle enzyme, -ketoglutarate dehydrogenase?

A) citric acid

B) -ketoglutaric acid

C) NAD+

D) NADH

E) ADP

Answer:  D

Section:  5.2

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.6

21) In green and purple bacteria, electrons to reduce CO2 can come from

A) CO2.

B) H2O.

C) C6H12O6.

D) H2S.

E) chlorophyll.

Answer:  D

Section:  5.9

Blooms Taxonomy:  Knowledge

ASMcue Outcome:  3.1

Learning Outcome:  5.23

22) Assume you are growing bacteria on a lipid medium that started at pH 7. The action of bacterial lipases should cause the pH of the medium to

A) increase.

B) decrease.

C) stay the same.

Answer:  B

Section:  5.5

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  3.2

Learning Outcome:  5.17

23) Which of the following uses CO2 for carbon and H2 for energy?

A) chemoautotroph

B) chemoheterotroph

C) photoautotroph

D) photoheterotroph

Answer:  A

Section:  5.9

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  3.1

Learning Outcome:  5.23

24) Which of the following uses glucose for carbon and energy?

A) chemoautotroph

B) chemoheterotroph

C) photoautotroph

D) photoheterotroph

Answer:  B

Section:  5.9

Blooms Taxonomy:  Knowledge

ASMcue Outcome:  3.1

Learning Outcome:  5.23

25) Which of the following has bacteriochlorophylls and uses alcohols for carbon?

A) chemoautotroph

B) chemoheterotroph

C) photoautotroph

D) photoheterotroph

Answer:  D

Section:  5.9

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  3.1

Learning Outcome:  5.23

26) Cyanobacteria are a type of

A) chemoautotroph.

B) chemoheterotroph.

C) photoautotroph.

D) photoheterotroph.

Answer:  C

Section:  5.9

Blooms Taxonomy:  Knowledge

ASMcue Outcome:  3.1

Learning Outcome:  5.23

27) Which of the following statements are TRUE?

1-Electron carriers are located at ribosomes.

2-ATP is a common intermediate between catabolic and anabolic pathways.

3-ATP is used for the long-term storage of energy and so is often found in storage granules.

4-Anaerobic organisms are capable of generating ATP via respiration.

5-ATP can be generated by the flow of protons across protein channels.

A) 2, 4, 5

B) 1, 3, 4

C) 2, 3, 5

D) 1, 2, 3

E) All of the statements are true.

Answer:  A

Section:  5.1

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.2

28) Microorganisms that catabolize sugars into ethanol and hydrogen gas would most likely be categorized as

A) aerobic respirers.

B) anaerobic respirers.

C) heterolactic fermenters.

D) homolactic fermenters.

E) alcohol fermenters.

Answer:  C

Section:  5.4

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  3.1

Learning Outcome:  5.16

Global Outcome:  2

29) Which of the following statements regarding metabolism is FALSE?

A) Heat may be released in both anabolic and catabolic reactions.

B) ATP is formed in catabolic reactions.

C) ADP is formed in anabolic reactions.

D) Anabolic reactions are degradative.

Answer:  D

Section:  5.1

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.1

30) Which of the following is TRUE about this reaction?

NO3+ 2H+ NO2 + H2O

Nitrate ion Nitrite ion

A) This process requires O2.

B) This process occurs anaerobically.

C) This process requires the entire electron transport system.

D) This process requires light.

E) This process requires O2 and the electron transport system.

Answer:  B

Section:  5.4

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  3.1

Learning Outcome:  5.15

Global Outcome:  2

31) Which of the following statements regarding the Entner-Doudoroff pathway is TRUE?

A) It involves glycolysis.

B) It involves the pentose phosphate pathway.

C) NADH is generated.

D) ATP is generated.

E) NADH and ATP are generated.

Answer:  D

Section:  5.4

Blooms Taxonomy:  Knowledge

ASMcue Outcome:  3.1

Learning Outcome:  5.12

32) Assume you are working for a chemical company and are responsible for growing a yeast culture that produces ethanol. The yeasts are growing well on the maltose medium but are not producing alcohol. What is the most likely explanation?

A) The maltose is toxic.

B) O2 is in the medium.

C) Not enough protein is provided.

D) The temperature is too low.

E) The temperature is too high.

Answer:  B

Section:  5.4

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  3.2

Learning Outcome:  5.15

33) Figure 5.6

The rates of O2 and glucose consumption by a bacterial culture are shown in Figure 5.6. Assume a bacterial culture was grown in a glucose medium without O2. Then O2 was added at the time marked X. The data indicate that

A) these bacteria dont use O2.

B) these bacteria get more energy anaerobically.

C) aerobic metabolism is more efficient than fermentation.

D) these bacteria cannot grow anaerobically.

Answer:  C

Section:  5.4

Blooms Taxonomy:  Analysis

ASMcue Outcome:  3.2

Learning Outcome:  5.15

Global Outcome:  3

34) An enzyme, citrate synthase, in the Krebs cycle is inhibited by ATP. This is an example of all of the following EXCEPT

A) allosteric inhibition.

B) competitive inhibition.

C) feedback inhibition.

D) noncompetitive inhibition.

Answer:  B

Section:  5.2

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.5

35) If a cell is starved for ATP, which of the following pathways would most likely be shut down?

A) Krebs cycle

B) glycolysis

C) pentose phosphate pathway

D) Krebs cycle and glycolysis

Answer:  C

Section:  5.4

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.12

36) Which of the following statements regarding the glycolysis pathway is FALSE?

A) Two pyruvate molecules are generated.

B) Four ATP molecules are generated via substrate-level phosphorylation.

C) Two NADH molecules are generated.

D) One molecule of ATP is expended.

E) Two molecules of water are generated.

Answer:  D

Section:  5.4

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.11

37) Figure 5.7

The graph at the left in Figure 5.7 shows the reaction rate for an enzyme at its optimum temperature. Which graph shows enzyme activity at a higher temperature?

A) a

B) b

C) c

D) d

Answer:  B

Section:  5.2

Blooms Taxonomy:  Analysis

ASMcue Outcome:  7.2a

Learning Outcome:  5.5

Global Outcome:  3

38) A bacterial culture grown in a glucose-peptide medium causes the pH to increase. The bacteria are most likely

A) fermenting the glucose.

B) oxidizing the glucose.

C) using the peptides.

D) not growing.

Answer:  C

Section:  5.5

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  3.2

Learning Outcome:  5.17

39) Gallionella bacteria can get energy from the reaction Fe2+ Fe3+. This reaction is an example of

A) oxidation.

B) reduction.

C) fermentation.

D) photophosphorylation.

E) the Calvin-Benson cycle.

Answer:  A

Section:  5.3

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  3.1

Learning Outcome:  5.8

Figure 5.8

40) In Figure 5.8, where is ATP produced?

A) a

B) b

C) c

D) d

E) e

Answer:  E

Section:  5.4

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.14

41) Refer to Figure 5.8. In aerobic respiration, where is water formed?

A) a

B) b

C) c

D) d

E) e

Answer:  D

Section:  5.4

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.14

42) In Figure 5.8, the structure labeled 1 is

A) NAD+.

B) ATP synthase.

C) a plasma membrane.

D) a cell wall.

E) cytoplasm.

Answer:  C

Section:  5.4

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.14

43) In Figure 5.8, the path labeled 2 is the flow of

A) electrons.

B) protons.

C) energy.

D) water.

E) glucose.

Answer:  B

Section:  5.4

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.14

44) What is the most acidic place in Figure 5.8?

A) a

B) b

C) c

D) d

E) e

Answer:  A

Section:  5.4

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.14

Global Outcome:  7

45) A urease test is used to identify Mycobacterium tuberculosis because

A) urease is a sign of tuberculosis.

B) M. tuberculosis produces urease.

C) urea accumulates during tuberculosis.

D) some bacteria reduce nitrate ion.

E) M. bovis can cause tuberculosis.

Answer:  B

Section:  5.9

Blooms Taxonomy:  Knowledge

ASMcue Outcome:  8.3

Learning Outcome:  5.18

46) Researchers are developing a ribozyme that cleaves the HIV genome. This pharmaceutical agent could be described as

A) an RNA molecule capable of catalysis.

B) a hydrolase.

C) a genetic transposable element.

D) a protease inhibitor.

E) a competitive inhibitor for reverse transcriptase.

Answer:  A

Section:  5.2

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  3.4

Learning Outcome:  5.7

Global Outcome:  7

47) Which statements correspond to amphibolic pathways?

1. anabolic and catabolic reactions are joined through common intermediate

2. shared metabolic pathways

3. Feedback inhibition can help regulate rates of reactions

4. both types of reactions are necessary but do not occur simultaneously

A) 1 only

B) 1, 2, 3

C) 1, 2, 3, 4

D) 2, 4

E) 2, 3, 4

Answer:  B

Section:  5.11

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.25

5.2   True/False Questions

1) Catabolic reactions are generally degradative and hydrolytic.

Answer:  TRUE

Section:  5.1

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.1

2) The pentose phosphate pathway can be characterized as an anabolic pathway.

Answer:  FALSE

Section:  5.4

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.12

3) In general, ATP is generated in catabolic pathways and expended in anabolic pathways.

Answer:  TRUE

Section:  5.1

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.2

4) An apoenzyme that loses its coenzyme subunit will be non-functional.

Answer:  TRUE

Section:  5.2

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.3

5) The use of enzymes is necessary to increase the activation energy requirements of a chemical reaction.

Answer:  FALSE

Section:  5.2

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.4

6) Glycolysis is utilized by cells in both respiration and fermentation.

Answer:  TRUE

Section:  5.4

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.15

7) Carbon fixation occurs during the light-independent phase of photosynthesis.

Answer:  TRUE

Section:  5.7

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.20

8) Both respiration and photosynthesis require the use of an electron transport chain.

Answer:  TRUE

Section:  5.4; 5.7

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.21

9) Both respiration and photosynthesis use water molecules for the donation of hydrogen ions.

Answer:  FALSE

Section:  5.4; 5.7

Blooms Taxonomy:  Comprehension

Learning Outcome:  5.21

10) Once an enzyme has converted substrates into products, the active site reverts back to its original form.

Answer:  TRUE

Section:  5.2

Blooms Taxonomy:  Knowledge

Learning Outcome:  5.4

5.3   Essay Questions

1) Compare and contrast photophosphorylation and oxidative phosphorylation.

Section:  5.4; 5.7

Blooms Taxonomy:  Analysis

ASMcue Outcome:  7.3a

Learning Outcome:  5.21

Global Outcome:  8

2) Rhodopseudomonas is an anaerobic photoautotroph that uses organic compounds as an electron donor. It is also capable of chemoheterotrophic metabolism. Diagram the metabolic pathways of this bacterium.

Section:  5.9

Blooms Taxonomy:  Application

ASMcue Outcome:  3.1

Learning Outcome:  5.23

Global Outcome:  2

3) Differentiate the following two laboratory tests: starch hydrolysis and starch fermentation.

Section:  5.6

Blooms Taxonomy:  Application

ASMcue Outcome:  7.3a; 8.3

Learning Outcome:  5.18

Global Outcome:  8

4) Streptococcus lacks an electron transport chain. How does this bacterium reoxidize NADH? Where is the NADH formed?

Section:  5.4

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  7.3a

Learning Outcome:  5.16

Global Outcome:  8

5) You look in the refrigerator and find some orange drink you had forgotten was there. The drink now has an off taste and bubbles. What is the most likely explanation for the changes in the drink?

Section:  5.4

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  7.3a

Learning Outcome:  5.16

Global Outcome:  8

6) Explain the overall purpose of metabolic pathways.

Section:  5.3

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  7.3a

Learning Outcome:  5.10

Global Outcome:  8

7) Summarize energy production in cells in a single sentence.

Section:  5.8

Blooms Taxonomy:  Comprehension

ASMcue Outcome:  7.3a

Learning Outcome:  5.22

Global Outcome:  8

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