Deck 5: Microbial Metabolism

Question 1

Aerobic respiration differs from anaerobic respiration in which of the following respects?

A) The final electron acceptors are different.
B) Anaerobic respiration is glycolysis.
C) Aerobic respiration requires the electron transport chain.
D) Aerobic respiration gets electrons from the Krebs cycle.
E) Aerobic respiration produces more ATP.

Answer 1

The final electron acceptors are different.

Question 2

Beggiatoa bacteria get energy by oxidizing S^2- to S⁶⁺. This means they take (1) for their
(2) .

A) 1- protons; 2- NAD⁺
B) 1- electrons; 2- electron transport chain
C) 1- glucose; 2- glycolysis
D) 1- electrons; 2- fermentation
E) 1- sulfur; 2- photophosphorylation

Answer 2

1- electrons; 2- electron transport chain

Question 3

Figure 5.2

What type of reaction is in Figure 5.2?

A) Reduction
B) Decarboxylation
C) Dehydrogenation
D) Oxidation
E) Transamination

Answer 3

E

Question 4

How is ATP generated in the reaction in Figure 5.4?

A) Fermentation
B) Glycolysis
C) Oxidative phosphorylation
D) Substrate- level phosphorylation
E) Photophosphorylation

Question 5

All the following are true about substrate- level phosphorylation except

A) It occurs in glycolysis.
B) The oxidation of intermediate metabolic compounds releases energy that is used to generate ATP.
C) No final electron acceptor is required.
D) It involves the direct transfer of a high- energy phosphate group from an intermediate metabolic compound to ADP.
E) All of the above are true.

Question 6

The advantage of the pentose phosphate pathway is that it produces all of the following except

A) Precursors for nucleic acids.
B) NADPH.
C) Precursors for the synthesis of glucose.
D) Precursors for the synthesis of amino acids.
E) Three ATPs.

Question 7

Which of the following is not necessary for respiration?

A) Oxygen
B) Quinones
C) A source of electrons
D) Flavoproteins
E) Cytochromes

Question 8

Uses glucose for carbon and energy.

A) Photoheterotroph
B) Chemoheterotroph
C) Chemoautotroph
D) Photoautotroph
E) None of the above

Question 9

Figure 5.7

The graph at the left of 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
E) e

Question 10

Which of the following is not true about beta oxidation?

A) It involves the formation of acetyl- CoA.
B) It involves the formation of 2- carbon units.
C) It is a method of catabolizing fatty acids.
D) It is a step in glycolysis.
E) None of the above.

Question 11

Which of the following compounds is not an enzyme?

A) Cellulase
B) fi- galactosidase
C) Dehydrogenase
D) Coenzyme A
E) None of the above

Question 12

Which of the following is not true about photophosphorylation?

A) The oxidation of carrier molecules releases energy.
B) It occurs in photosynthesizing cells.
C) Energy from oxidation reactions is used to generate ATP from ADP.
D) Light liberates an electron from chlorophyll.
E) It requires CO₂.

Question 13

How many molecules of ATP can be generated from the complete oxidation of glucose to CO₂ and H₂O?

A) 4
B) 76
C) 38
D) 2
E) 34

Question 14

Which of the following is not an end- product of fermentation?

A) Acetone
B) Pyruvic acid
C) Glycerol
D) Ethyl alcohol
E) Lactic acid

Question 15

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

A) The energy released as carrier molecules are oxidized is used to generate ATP.
B) Electrons are passed through a series of carriers to O₂.
C) The energy released in the reduction of carrier molecules is used to generate ATP.
D) The transfer of a high- energy phosphate group to ADP.

Question 16

Figure 5.1

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

A) Isocitric acid and a- ketoglutaric acid
B) NADH
C) NADH and isocitric acid
D) NAD+
E) a- ketoglutaric acid and NAD+

Question 17

Has bacteriochlorophylls and uses alcohols for carbon.

A) Chemoheterotroph
B) Photoheterotroph
C) Chemoautotroph
D) Photoautotroph
E) None of the above

Question 18

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.

Question 19

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

A) NADH
B) NAD+
C) Citric acid
D) a- ketoglutaric acid
E) All of the above

Question 20

Which of the following is the best definition of fermentation?

A) The oxidation of glucose with organic molecules serving as electron acceptors.
B) The production of energy by substrate- level phosphorylation.
C) The complete catabolism of glucose to CO₂ and H₂O.
D) The production of ethyl alcohol from glucose.
E) The reduction of glucose to pyruvic acid.

Question 21

Which 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 respiration.
5-ATP is generated by the flow of protons across the cell membrane.

A) 1, 2, 3
B) 2, 3, 5
C) 1, 3, 4
D) 2, 4, 5
E) All

Question 22

Cyanobacteria are an example of this type.

A) Chemoheterotroph
B) Photoautotroph
C) Chemoautotroph
D) Photoheterotroph
E) None of the above

Question 23

What percent of the total ATP produced from the complete catabolism of glucose is produced by aerobic respiration?

A) 50%
B) 95%
C) 5%
D) 11%
E) 89%

Question 24

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

A) Fermenting the glucose.
B) Using the peptides.
C) Oxidizing the glucose.
D) Not growing.

Question 25

A shipping company employee notices that the inside of ships' hulls where ballast water is stored are deteriorating. The hull paint contained cyanide to prevent microbial growth. Since bacteria were growing on the hulls, you can conclude that the

A) Bacteria were using aerobic respiration.
B) Bacteria were growing by fermentation.
C) Bacteria were using anaerobic respiration.
D) Bacteria were using cytochromes.
E) None of the above.

Question 26

Fatty acids are catabolized in

A) The electron transport chain.
B) The Entner Doudoroff pathway.
C) The pentose phosphate pathway.
D) Glycolysis.
E) The Krebs cycle.

Question 27

Uses CO₂ for carbon and H₂ for energy.

A) Chemoheterotroph
B) Photoheterotroph
C) Photoautotroph
D) Chemoautotroph
E) None of the above

Question 28

Figure 5.4

An enzyme, citrate synthase, in the Krebs cycle is inhibited by ATP; this is an example of all of the following except

A) Noncompetitive inhibition.
B) Competitive inhibition.
C) Feedback inhibition.
D) Allosteric inhibition.
E) None of the above.

Question 29

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 can't grow anaerobically.
B) These bacteria get more energy anaerobically.
C) Aerobic metabolism is more efficient than fermentation.
D) These bacteria don't use O₂.

Question 30

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

Question 31

Which of the following is not true about anaerobic respiration?

A) It generates ATP.
B) It involves the Krebs cycle.
C) It involves glycolysis only.
D) It requires cytochromes.
E) It involves the reduction of nitrate.

Question 32

A strictly fermentative bacterium produces energy

A) By aerobic respiration only.
B) Only in the absence of oxygen.
C) Only in the presence of oxygen.
D) By glycolysis only.
E) By fermentation or aerobic respiration.

Question 33

Figure 5.3

How would a noncompetitive inhibitor interfere with a reaction involving the enzyme 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) Can't tell.

Question 34

When oxygen is unavailable, Halobacterium produce ATP by

A) Substrate- level phosphorylation.
B) Fermentation.
C) The Krebs cycle.
D) Photophosphorylation.
E) Oxidative phosphorylation.

Question 35

According to the chemiosmotic mechanism, ATP is generated when

A) Protons are moved across a membrane.
B) Cells lyse in a hypotonic environment.
C) Chlorophyll liberates an electron.
D) A high- energy phosphate group is transferred from an intermediate metabolite to ADP.
E) Electrons are transferred between carrier molecules.

Question 36

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

A) It is oxidized in the electron transport chain.
B) It is reduced in the Krebs cycle.
C) It is catabolized in glycolysis.
D) It is reduced to lactic acid.
E) It is oxidized in the Krebs cycle.

Question 37

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

A) Yeasts don't produce ethyl alcohol.
B) O₂ is in the medium.
C) Not enough protein is provided.
D) The maltose is toxic.
E) None of the above.

Question 38

In green and purple bacteria, electrons to reduce CO₂come from

A) C₆H₁₂O₆
B) H₂O
C) Sunlight
D) Chlorophyll
E) CO₂