Micro Chapter 5

25 July 2022
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1) The conversion of amino acids to carbohydrates is an example of 1) A) substrate-level phosphorylation. B) electron transport. C) gluconeogenesis. D) amination. E) beta-oxidation.
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C) gluconeogenesis.
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2) Which of the following statements concerning glycolysis is TRUE? 2) A) It involves ribulose 5-phosphate as an intermediate. B) It produces ATP by oxidative phosphorylation. C) It occurs in the cell membranes of bacteria. D) It both requires the input of ATP and produces ATP. E) It is an alternative to fermentation.
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D) It both requires the input of ATP and produces ATP.
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3) Which of the following is TRUE concerning the structure and function of enzymes? 3) A) Competitive inhibition of an enzyme occurs when an inhibitor binds to an allosteric site on the enzyme. B) After an enzyme has catalyzed a reaction, it resumes its original shape and can interact with a new substrate molecule. C) All enzymes bind cofactors necessary for their function. D) Enzymes can function at a wide range of pH. E) An apoenzyme is a combination of a cofactor bound to a holoenzyme.
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B) After an enzyme has catalyzed a reaction, it resumes its original shape and can interact with a new substrate molecule.
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4) Substrate-level phosphorylation occurs during the ________ stage(s) of glycolysis. 4) A) lysis B) energy-conservation C) energy-investment D) energy-investment and energy-conservation E) energy-investment, lysis, and energy-conservation
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D) energy-investment and energy-conservation
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5) If a cell reverses the process of beta-oxidation, which of the following molecules will it make? 5) A) starch B) glycerol C) amino acids D) nucleotides E) fatty acids
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E) fatty acids
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6) During the synthesis of acetyl-CoA from pyruvic acid, ________ is produced. 6) A) FADH2 B) ATP C) H2O D) acetic acid E) NADH
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E) NADH
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Identify the processes of glucose metabolism represented in Figure 5-1. 7) A) A = electron transport chain, B = Krebs cycle, C = glycolysis, D = fermentation B) A = glycolysis, B = fermentation, C = Krebs cycle, D = electron transport chain. C) A = glycolysis, B = Krebs cycle, C = fermentation, D = electron transport chain D) A = glycolysis, B = Krebs cycle, C = electron transport chain, D = fermentation. E) A = fermentation, B = glycolysis, C = Krebs cycle, D = electron transport chain
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B) A = glycolysis, B = fermentation, C = Krebs cycle, D = electron transport chain.
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8) Which of the following statements concerning cellular metabolism is FALSE? 8) A) Energy obtained from nutrients or light is stored in the bonds of ATP. B) Enzymes are used in both catabolic and anabolic reactions. C) The goal of metabolism is reproduction of the organism. D) ATP is used in the formation of macromolecules. E) Macromolecules are converted into cell structures via catabolism.
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E) Macromolecules are converted into cell structures via catabolism.
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9) Which of the following can be the final electron acceptor in anaerobic respiration in bacteria? 9) A) sulfate only B) pyruvic acid only C) nitrate only D) both nitrate and sulfate E) nitrate, pyruvic acid, and sulfate
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D) both nitrate and sulfate
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10) Reactions involving ligases are typically ________ reactions. 10) A) anabolic B) catabolic C) both anabolic and catabolic D) neither anabolic nor catabolic E) exergonic
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A) anabolic
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11) The various types of chlorophyll differ in the 11) A) amount of oxygen they utilize. B) wavelengths of light they absorb. C) amount of ATP they produce. D) number of electrons they release. E) amount of light they can absorb.
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B) wavelengths of light they absorb.
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12) When a cell forms an amino acid by adding an amine group derived from ammonia to a precursor metabolite, this process is called 12) A) deamination. B) reduction. C) amination. D) polymerization. E) transamination.
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C) amination.
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13) Chemical reactions that can proceed toward either anabolism or catabolism are called 13) A) amphibolic. B) synthetic. C) cyclic. D) glycolytic. E) light-independent.
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A) amphibolic
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14) What is the major product of the Calvin-Benson cycle that can then be used to form glucose? 14) A) ATP B) CO2 C) NADPH D) RuBP E) glyceraldehyde 3-phosphate
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E) glyceraldehyde 3-phosphate
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15) Which of the following statements concerning reduction reactions is FALSE? 15) A) They are coupled with oxidation reactions. B) An electron acceptor gains an electron. C) They frequently involve electron carrier molecules. D) An electron acceptor becomes more positively charged. E) A molecule gains a hydrogen atom.
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D) An electron acceptor becomes more positively charged.
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16) Which of the following statements concerning enzymes is FALSE? 16) A) They are usually, but not always, proteins. B) They form a temporary intermediate compound with a substrate. C) They can be denatured if the pH of their environment is too high or too low. D) They always function best at 37°C. E) They can be used to catalyze a chemical reaction over and over again.
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D) They always function best at 37°C.
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17) All of the following are forms of oxidation EXCEPT 17) A) substrate level phosphorylation. B) loss of hydrogen atom. C) a dehydrogenation event. D) loss of an electron. E) gain of an oxygen atom and its electrons.
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A) substrate level phosphorylation.
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18) The production of NADH takes place during the ________ stage(s) of glycolysis. 18) A) energy-investment B) energy-conservation C) lysis D) lysis and energy-investment E) energy-investment and energy-conservation
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B) energy-conservation
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20) How many ATP molecules can theoretically be produced from the NADH generated by the catabolism of a molecule of glucose during aerobic respiration? 20) A) 34 B) 4 C) 30 D) 38 E) 36
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C) 30
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19) Glycolysis begins with a(n) ________ stage(s). 19) A) energy-investment B) energy-conservation C) lysis D) lysis and energy-conservation E) energy-investment and conservation
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A) energy-investment
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21) Which of the following is/are common to chemiosmosis and the light-dependent reactions of photosynthesis? 21) A) electron transport only B) a proton gradient only C) reduction of NADP+ only D) both electron transport and a proton gradient E) electron transport, a proton gradient, and reduction of NADP+
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D) both electron transport and a proton gradient
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22) Which of the following is required for holoenzyme function? 22) A) a protein cofactor B) a substrate C) a coenzyme D) an activator E) an allosteric inhibitor
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C) a coenzyme
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23) Where is the majority of ATP generated in most eukaryotic cells? 23) A) in the outer membrane of the mitochondria B) in the cytosol C) in the mitochondrial matrix D) in the cytoplasmic membrane E) on ribosomes
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C) in the mitochondrial matrix
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24) Which of the following produces NADPH? 24) A) the Embden-Meyerhof pathway only B) the pentose phosphate pathway only C) the Entner-Doudoroff pathway only D) both the Embden-Meyerhof and Entner-Doudoroff pathways E) both the pentose phosphate and Entner-Doudoroff pathways
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E) both the pentose phosphate and Entner-Doudoroff pathways
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25) During reactions catalyzed by oxidoreductases an electron donor is 25) A) oxidized. B) degraded. C) unaltered. D) reduced. E) synthesized.
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A) oxidized.
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26) Pyruvic acid is a product of 26) A) glycolysis only. B) both glycolysis and the Entner-Doudoroff pathway. C) fermentation. D) the Krebs cycle. E) the Entner-Doudoroff pathway only.
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B) both glycolysis and the Entner-Doudoroff pathway.
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27) Isomerases catalyze reactions in which 27) A) atoms in biomolecules are rearranged. B) biomolecules are broken down into their component parts. C) biomolecules are oxidized or reduced. D) groups are transferred from one molecule to another. E) biomolecules are assembled from smaller molecules.
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A) atoms in biomolecules are rearranged.
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28) Which of the following is a non-protein carrier found in some electron transport chains? 28) A) cytochromes B) ribozymes C) flavoproteins D) ubiquinones E) metal-containing proteins
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D) ubiquinones
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29) Which of the following is a fermentation product useful in the manufacture of cheese? 29) A) ethanol B) ammonia C) pyruvic acid D) acetic acid E) lactic acid
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E) lactic acid
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30) What is the purpose of the light-dependent reactions of photosynthesis? 30) A) production of oxygen B) carbon fixation C) regeneration of NAD+ D) production of ATP and NADPH E) production of ATP and NADH
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D) production of ATP and NADPH
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31) Enzymes known as lyases participate in ________ reactions. 31) A) anabolic B) catabolic C) both anabolic and catabolic D) neither anabolic nor catabolic E) oxidation-reduction
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B) catabolic
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32) Although glycolysis requires an input of ATP, this pathway results in a net gain of two ATP; therefore it is a(n) ________ pathway. 32) A) reductive B) oxidative C) endergonic D) exergonic E) neither exergonic nor endergonic
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D) exergonic
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33) The metabolic processes called fermentation 33) A) produce substrates for glycolysis. B) occur only when oxygen is readily available. C) use an organic molecule as a final electron acceptor. D) produce substrates for the Krebs cycle. E) are alternatives for the pentose phosphate pathway.
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C) use an organic molecule as a final electron acceptor.
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34) Anabolic reactions may be characterized as 34) A) producing ATP. B) breaking large molecules into smaller molecules to produce ATP. C) exergonic. D) forming large molecules from smaller molecules. E) breaking large molecules into smaller molecules.
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D) forming large molecules from smaller molecules.
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35) Which of the following is associated with the Calvin-Benson cycle? 35) A) TMAO B) acetyl-CoA C) RuBP D) FADH2 E) PABA
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C) RuBP
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36) A catabolic process which occurs in eukaryotic mitochondria is 36) A) Calvin-Benson cycle. B) beta-oxidation. C) deamination. D) Entner-Doudoroff pathway. E) fermentation.
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B) beta-oxidation.
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37) Which of the following is a by-product of the catabolism of proteins? 37) A) acetyl-CoA B) lactic acid C) carbon dioxide D) ammonia E) proteases
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D) ammonia
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38) Which of the following products of glucose catabolism is a substrate for fatty acid synthesis? 38) A) acetyl-CoA B) phosphoglyceric acid C) pyruvic acid D) oxaloacetate E) succinyl-CoA
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A) acetyl-CoA
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39) Hydrolases are generally involved in ________ reactions. 39) A) anabolic B) catabolic C) both anabolic and catabolic D) neither anabolic nor catabolic E) oxidation-reduction
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B) catabolic
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40) The conversion of pyruvic acid to acetyl-CoA can be described as ________, because a molecule of CO2 is produced as a by-product. 40) A) amination B) respiration C) phosphorylation D) decarboxylation E) oxidation
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D) decarboxylation
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41) All of the following are aspects of a cell's ability to regulate its metabolism EXCEPT 41) A) synthesis or degradation of membrane transport proteins. B) use of the most energy-efficient energy source available. C) isolation of various enzymes within membranous organelles. D) use of the same coenzymes for anabolic and catabolic reactions that share substrate molecules. E) synthesis of a catabolic enzyme only when its substrate is available.
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D) use of the same coenzymes for anabolic and catabolic reactions that share substrate molecules.
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42) Beta-oxidation of fatty acids produces a substrate of the 42) A) Entner-Doudoroff pathway. B) Embden-Meyerhof pathway. C) pentose phosphate pathway. D) Krebs cycle. E) Calvin-Benson cycle.
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D) Krebs cycle.
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43) The molecule that an enzyme acts upon is known as its 43) A) catalyst. B) holoenzyme. C) coenzyme. D) substrate. E) apoenzyme.
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D) substrate.
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44) Light energy is used to fuel the assembly of carbon dioxide and water into carbohydrates in the process known as 44) A) photosynthesis. B) fermentation. C) chemiosmosis. D) oxidation. E) gluconeogenesis.
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A) photosynthesis.
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45) Photosystems are assembled in 45) A) stroma. B) thylakoids. C) cytochromes. D) grana. E) cristae.
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B) thylakoids.
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46) Sulfanilamide is an antimicrobial drug that mimics the shape of an important substrate for a particular bacterial enzyme, thereby inhibiting the enzyme. This type of inhibition is known as 46) A) noncompetitive inhibition. B) excitatory allosteric control. C) allosteric inhibition. D) feedback inhibition. E) competitive inhibition.
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E) competitive inhibition.
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47) Only Photosystem I is required for (cyclic/noncyclic) photophosphorylation to occur.
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cyclic
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48) Laboratory fermentation tests often include a pH indicator because many bacteria produce (CO2/bases/acids) as they ferment carbohydrates.
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acids
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49) Another term for a protein catalyst is a(n) (enzyme/ribozyme).
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enzyme
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50) A (photosystem/thylakoid/grana) is a collection of pigments such as chlorophyll that are used to absorb light in the light-dependent reactions of photosynthesis.
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photosystem
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51) The conversion of phosphoenol pyruvic acid (PEP) to pyruvic acid results in the production of an ATP. This reaction is an example of (substrate-level/oxidative) phosphorylation.
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substrate-level
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52) The purpose of electron transport is to create a proton (concentration/gradient/pump) across a membrane that can then be used to make ATP.
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gradient
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53) A(n) (oxidation/reduction/transport) reaction is one in which a molecule accepts an electron.
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reduction
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54) The (transferases/transaminases/deaminases) generate amino acids from carbohydrate precursors and glutamic acid.
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transaminases/
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55) Anaerobic respiration involves the use of molecules other than oxygen as the final electron (acceptor/donor) in an electron transport chain.
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acceptor
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56) Enzymes increase the rate of reaction by lowering the (activation/reaction) energy.
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activation
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57) Electrons are transferred in the Krebs cycle in the form of (oxygen/hydrogen) atoms to NAD+ and FAD.
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hydrogen
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58) During glycolysis, glucose is converted to (pyruvic/acetic/lactic) acid, a molecule that can be used in either fermentation or respiration pathways
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pyruvic
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59) When a noncompetitive inhibitor molecule binds to an (active/allosteric) site on an enzyme, the shape of the active site changes so that the substrate molecules can no longer bind.
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allosteric
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60) Significant amounts of the NADPH required for the Calvin-Benson cycle are produced during the (cyclic/noncyclic) photophosphorylation reactions of photosynthesis
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noncyclic
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61) Waste products such as sulfur are produced by (oxygenic/anoxygenic/aerobic) photosynthetic bacteria as they obtain electrons for noncyclic photophosphorylation.
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anoxygenic
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62) The (activation /inhibition/saturation) point of an enzyme is reached when all active sites have bound substrate molecules.
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saturation
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63) The ability to utilize different metabolites for cellular respiration is one method for identifying bacteria.
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true
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64) During chemiosmosis, electrons are pumped across a membrane to produce ATP.
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false
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65) Synthesis of the precursors of purines and pyrimidines requires transamination of ribose-5-phosphate.
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false
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66) Reactions that are both catabolic and anabolic are amphibolic.
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true
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67) Some photosynthetic bacteria use chlorophylls other than chlorophyll a.
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true
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68) As the concentration of substrate increases, the activity of the enzyme decreases.
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false
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69) Environmental changes can result in the inactivation of enzymes.
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true
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70) Essential amino acids are amino acids that cannot be synthesized by an organism and so must be provided as nutrients.
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true
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71) The pentose phosphate pathway generates all the necessary precursors for nucleotide biosynthesis.
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false
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72) Ribozymes are enzymes that cleave the subunits of the ribosome.
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false