Chapter 5: Microbial Metabolism

25 July 2022
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coenzyme A
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Which of the following compounds is NOT an enzyme? a. dehydrogenase b. coenzyme A c. sucrase d. B-galactosidase e. cellulase
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NAD+
NAD+
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Which compound is being reduced in the reaction shown in Figure 5.1?
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photoautotroph- CO2
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Which organism is NOT correctly matched to its energy source? a. photoheterotroph- light b. chemoheterotroph- glucose c. chemoautotroph- NH3 d. photoautotroph- CO2 e. chemoautotroph- Fe2+
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It involves the reduction of an organic final electron acceptor.
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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 Kreb's cycle is utilized. c. It involves the reduction of an organic final electron acceptor. d. It requires cytochromes. e. It generates ATP.
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transamination
transamination
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What type of reaction is in Figure 5.2?
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pyruvic acid
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The fate of __________ in an organism that uses aerobic respiration is that it is converted to acetyl CoA.
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It would not bind to b
It would not bind to b
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How would a noncompetitive inhibitor interfere with a reaction involving the enzyme shown in Figure 5.3?
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substrate-level phosphorylation
substrate-level phosphorylation
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How is ATP generated in the reaction shown in Figure 5.4?
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Krebs cycle
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Fatty acids are oxidized in the ____________.
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graph c
graph c
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Which of the graphs in Figure 5.5 best illustrates the activity of an enzyme that is saturated with a substrate?
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oxidative phosphorylation
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The best definition for __________ is a proton gradient allows hydrogen ions to flow back into the cells through transmembrane protein channels, releasing energy that is used to generate ATP
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The oxidation of intermediate metabolic compounds release energy that is used to generate ATP.
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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. It occurs in glycolysis. c. The oxidation of intermediate metabolic compounds release energy that is used to generate ATP. d. No final electron acceptor is required. e. It occurs in the Krebs cycle
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It requires CO2.
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Which of the following statements about photophosphorylation is FALSE? a. Light liberates an electron from chlorophyll. b. It requires CO2. c. It occurs in photosynthesizing cells. d. The oxidation of carrier molecules releases energy. e. Energy from oxidation reactions is used to generate ATP from ADP.
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by glycolysis only
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A strictly fermentative bacterium produces energy _____________.
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3 ATPs
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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 amino acids d. 3 ATPs e. precursors for the synthesis of glucose
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It is a step in glycolysis
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Which of the following statements about beta oxidation is FALSE? a. It is a step in glycolysis b. It is used in petroleum degradation c. It involves the formation of 2-carbon units d. It involves the formation of acetyl-CoA e. It is a method of catabolizing fatty acids
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H2O
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In noncyclic photophosphorylation, O2 is released from __________.
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fermentation
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The best definition for ___________ is the partial oxidation of glucose with organic molecules serving as electron acceptors
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oxygen
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Which of the following is NOT necessary for respiration? a. quinones b. cytochromes c. flavoproteins d. oxygen e. a source of electrons
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NADH
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Which one of the following would you predict is an allosteric inhibitor of the Krebs cycle enzyme, a-ketoglutarate dehydrogenase? a. a-ketoglutaric acid b. ADP c. citric acid d. NADH e. NAD+
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H2S
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In green and purple bacteria, electrons to reduce CO2 can come from __________.
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decrease
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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 __________.
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chemoautotroph
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Which of the following uses CO2 for carbon and H2 for energy? a. chemoheterotroph b. chemoautotroph c. chemoheterotroph d. photoheterotroph
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chemoheterotroph
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Which of the following uses glucose for carbon and energy? a. photoheterotroph b. chemoautotroph c. chemoheterotroph d. photoautotroph
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photoheterotroph
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Which of the following has bacteriochlorophylls and uses alcohols for carbon? a. photoheterotroph b. photoautotroph c. chemoheterotroph d. chemoautotroph
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photoautotroph
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Cyanobacteria are a type of ___________.
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2, 4, 5
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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.
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heterolactic fermenters
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Microorganisms that catabolize sugars into ethanol and hydrogen gas would most likely be categorized as ___________.
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Anabolic reactions are degradative
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Which of the following statements regarding metabolism is FALSE? a. ATP is formed in catabolic reactions b. Anabolic reactions are degradative c. Heat may be released in both anabolic and catabolic reactions d. ADP is formed in anabolic reactions
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ATP is generated
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Which of the following statements regarding the Entner-Doudoroff pathway is TRUE? a. NADH is generated b. It involves the pentose phosphate pathway c. ATP is generated d. It involves glycolysis e. NADH and ATP are generated
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O2 is in the medium
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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?
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aerobic metabolism is more efficient than fermentation
aerobic metabolism is more efficient than fermentation
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The rates of O2 and glucose consumption by a bacterial culture as 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 ___________.
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competitive inhibition
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An enzyme, citrate synthase, in the Krebs cycle us inhibited by ATP. This is an example of all of the following EXCEPT a. allosteric inhibition b. noncompetitive inhibition c. competitive inhibition d. feedback inhibition
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pentose phosphate pathway
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If a cell is starved for ATP, which of the following pathways would most likely be shut down? a. glycolysis b. Kreb's cycle c. pentose phosphate pathway d. Kreb's cycle and glycolysis
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1 molecule of ATP is expended
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Which of the following statements regarding the glycolysis pathway is FALSE? a. 2 pyruvate molecules are generated b. 4 ATP molecules are generated via substrate-level phosphorylation c. 1 molecule of ATP is expended d. 2 molecules of water are generated e. 2 NADH molecules are generated
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graph b
graph b
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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
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using the peptides
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A bacterial culture grown in a glucose-peptide medium causes the pH to increase. The bacteria are most likely __________.
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oxidation
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Gallionella bacteria can get energy from the reaction Fe2+ ---> Fe3+. This reaction is an example of __________.
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1. e
2. d
3. plasma membrane
4. a
1. e 2. d 3. plasma membrane 4. a
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1. In Figure 5.8, where is ATP produced? 2. Where is water formed? 3. The structure labeled "1" is? 4. What is the most acidic place?
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M.T. produces urease
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A urease test is used to identify Myobacterium tuberculosis because ___________.
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true
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T/F: Catabolic reactions are generally degradative and hydrolytic
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false
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T/F: The pentose phosphate pathway can be characterized as an anabolic pathway
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false
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T/F: In general, ATP is generated in catabolic pathways and expended in anabolic pathways
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true
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T/F: An apoenzyme that loses its coenzyme subunit will be non-functional
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false
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T/F: The use of enzymes is necessary to increase the activation energy requirements of a chemical reaction
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true
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T/F: Glycolysis is utilized by cells in both respiration and fermentation
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true
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T/F: Carbon fixation occurs during the light-independent phase of photosynthesis
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true
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T/F: Both respiration and photosynthesis require the use of an electron transport chain
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false
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T/F: Both respiration and photosynthesis use water molecules for the donation of hydrogen ions
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true
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T/F: Once an enzyme has converted substrates into products, the active site reverts back to its original form