Chapter 5 PDF

Preview

Summary

test...

Description

Microbiology with Diseases by Body System, 5e (Bauman) Chapter 5 Microbial Metabolism 5.1 Multiple Choice Questions 1) Which of the following statements concerning cellular metabolism is FALSE? 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) Macromolecules are converted into cell structures via catabolism. D) The goal of metabolism is reproduction of the organism. E) ATP is used in the formation of macromolecules. Answer: C Bloom's Taxonomy: Application Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.1 2) Anabolic reactions may be characterized as A) exergonic. B) breaking large molecules into smaller molecules. C) forming large molecules from smaller molecules. D) producing ATP. E) breaking large molecules into smaller molecules to produce ATP. Answer: C Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.1 3) An organic compound gains an electron from another molecule. The organic compound A) has been oxidized. B) is an electron donor. C) has been reduced. D) has become more positively charged. E) has lost a hydrogen atom. Answer: C Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.2

1 Copyright © 2018 Pearson Education, Inc.

4) The molecule that an enzyme acts upon is known as its A) substrate. B) coenzyme. C) apoenzyme. D) product. E) catalyst. Answer: A Bloom's Taxonomy: Knowledge Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.6 5) Which of the following statements concerning enzymes is FALSE? A) They are usually, but not always, proteins. B) They always function best at 37°C. C) They can be denatured if the pH of their environment is too high or too low. D) They form a temporary intermediate compound with a substrate. E) They can be used to catalyze a chemical reaction over and over again. Answer: B Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.7 6) 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 A) allosteric inhibition. B) competitive inhibition. C) allosteric activation. D) noncompetitive inhibition. E) feedback inhibition. Answer: B Bloom's Taxonomy: Knowledge Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.7 7) Which of the following produces NADPH? A) the pentose phosphate pathway only B) the Calvin-Benson cycle only C) the Embden-Meyerhof pathway only D) both the Embden-Meyerhof and Calvin-Benson cycle pathways E) both the pentose phosphate and Entner-Doudoroff pathways Answer: E Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.25

2 Copyright © 2018 Pearson Education, Inc.

8) Which of the following statements concerning glycolysis is TRUE? A) The first step of glycolysis involves oxidative phosphorylation. B) The glycolytic pathway is cyclical. C) Glucose is activated by substrate-level phosphorylation. D) Ribulose 5-phosphate is an intermediate of glycolysis. E) Two NADH molecules are reduced during glycolysis. Answer: C Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.8 9) Many vitamins are important ________ of enzymes. A) protein cofactors B) coenzymes C) allosteric inhibitors D) competitive inhibitors E) activators Answer: B Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.6 10) Pyruvic acid is a product of A) the Krebs cycle. B) fermentation. C) glycolysis. D) the pentose phosphate pathway. E) both fermentation and the Krebs cycle. Answer: C Bloom's Taxonomy: Knowledge Section: Carbohydrate Catabolism Learning Outcome: 5.8 11) All of the following are forms of oxidation EXCEPT A) loss of an electron. B) loss of hydrogen atom. C) a dehydrogenation event. D) substrate-level phosphorylation. E) gain of an oxygen atom and its electrons. Answer: D Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.2, 5.3

3 Copyright © 2018 Pearson Education, Inc.

12) Anaerobic bacteria may use ________ as the final electron acceptor during anaerobic respiration. A) nitrate only B) carbon dioxide only C) sulfate only D) both nitrate and sulfate E) carbon dioxide, nitrate and sulfate Answer: D Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.10 13) Which of the following is a non-protein carrier found in some electron transport chains? A) flavoproteins B) metal-containing proteins C) ribozymes D) cytochromes E) ubiquinones Answer: E Bloom's Taxonomy: Knowledge Section: Carbohydrate Catabolism Learning Outcome: 5.11 14) The electron transport chain provides the energy for A) oxidative phosphorylation. B) substrate-level phosphorylation. C) beta-oxidation. D) photophosphorylation. E) anabolic reactions. Answer: A Bloom's Taxonomy: Knowledge Section: Basic Carbohydrate Catabolism Learning Outcome: 5.8 15) Which of the following is a by-product of the catabolism of proteins? A) lactic acid B) acetyl-CoA C) proteases D) ammonia E) carbon dioxide Answer: D Bloom's Taxonomy: Comprehension Section: Other Catabolic Pathways Learning Outcome: 5.19

4 Copyright © 2018 Pearson Education, Inc.

16) Which of the following is an active enzyme? A) apoenzyme B) cofactor C) coenzyme D) holoenzyme E) subtrate Answer: D Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.5 17) Which of the following is/are common to chemiosmosis and the light-dependent reactions of photosynthesis? A) reduction of NADP+ only B) electron transport only C) a proton gradient only D) both electron transport and a proton gradient E) electron transport, a proton gradient, and reduction of NADP+ Answer: D Bloom's Taxonomy: Application Section: Photosynthesis Learning Outcome: 5.12, 5.24 18) Which of the following is a fermentation product useful in the manufacture of cheese? A) acetic acid B) ammonia C) ethanol D) lactic acid E) pyruvic acid Answer: D Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.15 19) How many ATP molecules can theoretically be produced from the NADH generated by the catabolism of a molecule of glucose during aerobic respiration? A) 34 B) 30 C) 38 D) 36 E) 4 Answer: B Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.8

5 Copyright © 2018 Pearson Education, Inc.

20) The various types of chlorophyll differ in the A) amount of light they can absorb. B) amount of ATP they produce. C) number of electrons they release. D) amount of oxygen they utilize. E) wavelengths of light they absorb. Answer: E Bloom's Taxonomy: Knowledge Section: Photosynthesis Learning Outcome: 5.21 21) Which of the following metabolic processes is commonly used to identify bacteria? A) carbohydrate fermentation B) lipid catabolism C) Krebs cycle products D) lipid synthesis E) pentose phosphate pathway products Answer: A Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.16 22) Beta-oxidation of fatty acids produces a substrate of the A) pentose phosphate pathway. B) protein synthesis pathways. C) Embden-Meyerhof pathway. D) Krebs cycle. E) Calvin-Benson cycle. Answer: D Bloom's Taxonomy: Comprehension Section: Other Catabolic Pathways Learning Outcome: 5.18 23) Which of the following is associated with the Calvin-Benson cycle? A) acetyl-CoA B) TMAO C) RuBP D) FADH2 E) PABA Answer: C Bloom's Taxonomy: Knowledge Section: Photosynthesis Learning Outcome: 5.25

6 Copyright © 2018 Pearson Education, Inc.

24) The energy captured by photophosphorylation is used to produce glucose A) through the Calvin-Benson cycle. B) through the Krebs cycle. C) by cyclic phosphorylation. D) through the pentose-phosphate pathway. E) by beta-oxidation. Answer: A Bloom's Taxonomy: Comprehension Section: Photosynthesis Learning Outcome: 5.25 25) Chemical reactions that can proceed toward either anabolism or catabolism are called A) glycolytic. B) light-independent. C) synthetic. D) cyclic. E) amphibolic. Answer: E Bloom's Taxonomy: Knowledge Section: Other Anabolic Pathways Learning Outcome: 5.26 26) If a cell reverses the process of beta-oxidation, which of the following molecules will it make? A) glycerol B) amino acids C) fatty acids D) nucleotides E) starch Answer: C Bloom's Taxonomy: Comprehension Section: Other Anabolic Pathways Learning Outcome: 5.28 27) When a cell forms an amino acid by adding an amine group derived from ammonia to a precursor metabolite, this process is called A) amination. B) transamination. C) reduction. D) polymerization. E) deamination. Answer: A Bloom's Taxonomy: Knowledge Section: Other Anabolic Pathways Learning Outcome: 5.29

7 Copyright © 2018 Pearson Education, Inc.

28) The conversion of amino acids to carbohydrates is an example of A) amination. B) gluconeogenesis. C) substrate-level phosphorylation. D) beta-oxidation. E) electron transport. Answer: B Bloom's Taxonomy: Comprehension Section: Other Anabolic Pathways Learning Outcome: 5.27 29) Noncyclic photophosphorylation produces A) ATP only. B) oxygen. C) NADPH only. D) ATP and NADPH. E) water and ATP. Answer: D Bloom's Taxonomy: Comprehension Section: Photosynthesis Learning Outcome: 5.23 30) The metabolic processes called fermentation A) produce substrates for the Krebs cycle. B) are alternatives for the pentose phosphate pathway. C) use an organic molecule as a final electron acceptor. D) occur only when oxygen is readily available. E) produce substrates for glycolysis. Answer: C Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.15 31) Which of the following is TRUE concerning the structure and function of enzymes? A) All enzymes bind cofactors necessary for their function. B) An apoenzyme is a combination of a cofactor bound to a holoenzyme. C) Enzymes can function at a wide range of pH. D) Competitive inhibition of an enzyme occurs when an inhibitor binds to an allosteric site on the enzyme. E) After an enzyme has catalyzed a reaction, it resumes its original shape and can interact with a new substrate molecule. Answer: E Bloom's Taxonomy: Application Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.6

8 Copyright © 2018 Pearson Education, Inc.

32) Bacteriochlorophyll a absorbs ________ light. A) 350 nm, ultraviolet B) 425 nm, violet C) 660 nm, red D) both 425 & 660 nm (violet and red) E) all visible Answer: A Bloom's Taxonomy: Knowledge Section: Photosynthesis Learning Outcome: 5.21 33) Where is the majority of ATP generated in prokaryotic cells? A) in the cytoplasmic membrane B) in the cytosol C) in the thylakoids D) in the inner mitochondrial membrane E) on ribosomes Answer: A Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.9 34) The conversion of pyruvic acid to acetyl-CoA can be described as ________, because a molecule of CO2 is produced as a by-product. A) decarboxylation B) amination C) respiration D) oxidation E) phosphorylation Answer: A Bloom's Taxonomy: Knowledge Section: Carbohydrate Catabolism Learning Outcome: 5.9 35) Although glycolysis requires an input of ATP, this pathway results in a net gain of two ATP; therefore it is a(n) ________ pathway. A) exergonic B) endergonic C) oxidative D) reductive E) neither exergonic nor endergonic Answer: A Bloom's Taxonomy: Application Section: Carbohydrate Catabolism Learning Outcome: 5.1, 5.8

9 Copyright © 2018 Pearson Education, Inc.

36) Enzymes known as lyases participate in ________ reactions. A) anabolic B) catabolic C) both anabolic and catabolic D) neither anabolic nor catabolic E) oxidation-reduction Answer: B Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.4 37) The reactions of photosynthesis take place in the ________ of prokaryotes. A) thylakoids B) cytoplasm C) nucleoid D) cristae E) outer membrane Answer: A Bloom's Taxonomy: Comprehension Section: Photosynthesis Learning Outcome: 5.21 38) During the synthesis of acetyl-CoA from pyruvic acid, ________ is produced. A) ATP B) NADH C) FADH2 D) H2O E) acetic acid Answer: B Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.9 39) During reactions catalyzed by oxidoreductases an electron donor is A) oxidized. B) reduced. C) synthesized. D) degraded. E) unaltered. Answer: A Bloom's Taxonomy: Application Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.4

10 Copyright © 2018 Pearson Education, Inc.

40) Hydrolases are generally involved in ________ reactions. A) anabolic B) catabolic C) both anabolic and catabolic D) neither anabolic nor catabolic E) oxidation-reduction Answer: B Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.4 41) Reactions involving ligases are typically ________ reactions. A) anabolic B) catabolic C) both anabolic and catabolic D) neither anabolic nor catabolic E) exergonic Answer: A Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.4 42) Substrate-level phosphorylation occurs during which of the following stage(s) of glucose catabolism? A) formation of acetyl-CoA B) lysis stage of glycolysis C) energy-conservation stage of glycolysis D) Krebs cycle E) formation of acetyl-CoA and the Krebs cycle Answer: C Bloom's Taxonomy: Application Section: Carbohydrate Catabolism Learning Outcome: 5.3, 5.8, 5.9 43) The production of NADH takes place during the ________ stage(s) of glycolysis. A) energy-conservation B) energy-investment C) lysis D) lysis and energy-investment E) energy-investment and energy-conservation Answer: A Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.8

11 Copyright © 2018 Pearson Education, Inc.

44) Which of the following is the CORRECT sequence of stages in glycolysis? A) energy-conservation, energy-investment, lysis B) lysis, energy-investment, energy-conservation C) energy-investment, lysis, energy-conservation D) lysis,energy-conservation, energy-investment E) energy-investment, energy-conservation, lysis Answer: C Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.8 45)

Identify the processes of glucose metabolism represented in Figure 5.1. 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 = fermentation, B = glycolysis, C = Krebs cycle, D = electron transport chain D) A = glycolysis, B = Krebs cycle, C = fermentation, D = electron transport chain E) A = glycolysis, B = Krebs cycle, C = electron transport chain, D = fermentation Answer: B Bloom's Taxonomy: Application Section: Carbohydrate Catabolism Learning Outcome: 5.8

12 Copyright © 2018 Pearson Education, Inc.

46)

The process illustrated in the figure above is an example of a(n) ________ reaction. A) amination B) reduction C) oxidation D) transamination E) transferase Answer: A Bloom's Taxonomy: Comprehension Section: Other Anabolic Pathways Learning Outcome: 5.29 5.2 True/False Questions 1) Reactions that are both catabolic and anabolic are amphibolic. Answer: TRUE Bloom's Taxonomy: Knowledge Section: Other Anabolic Pathways Learning Outcome: 5.26 2) The amount of energy required for a reaction to occur is its activation energy. Answer: TRUE Bloom's Taxonomy: Knowledge Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.6 3) Accumulation of a metabolic pathway product may result in decreased activity of the pathway enzymes. Answer: TRUE Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.7 4) As the concentration of substrate increases, the activity of the enzyme decreases. Answer: FALSE Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.7 13 Copyright © 2018 Pearson Education, Inc.

5) All substrates for ribozymes are RNA molecules. Answer: FALSE Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.5 6) During chemiosmosis, electrons are pumped across a membrane to produce ATP. Answer: FALSE Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.12 7) Glyceraldehyde 3-phosphate is an intermediate in the Calvin-Benson cycle. Answer: TRUE Bloom's Taxonomy: Comprehension Section: Photosynthesis Learning Outcome: 5.25 8) All the precursors of amino acids are intermediates of glycolytic and fermentation pathways. Answer: FALSE Bloom's Taxonomy: Knowledge Section: Other Anabolic Pathways Learning Outcome: 5.29 9) Essential amino acids are amino acids that cannot be synthesized by an organism and so must be provided as nutrients. Answer: TRUE Bloom's Taxonomy: Knowledge Section: Other Anabolic Pathways Learning Outcome: 5.29 10) The pentose phosphate pathway generates all the necessary precursors for nucleotide biosynthesis. Answer: FALSE Bloom's Taxonomy: Knowledge Section: Other Anabolic Pathways Learning Outcome: 5.30 5.3 Short Answer Questions 1) 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/reductive) phosphorylation. Answer: substrate-level Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.3, 5.8 14 Copyright © 2018 Pearson Education, Inc.

2) Another term for a protein catalyst is a(n) (enzyme/ribozyme). Answer: enzyme Bloom's Taxonomy: Knowledge Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.5 3) A(n) (oxidation/reduction/transport) reaction is one in which a molecule accepts an electron. Answer: reduction Bloom's Taxonomy: Knowledge Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.2 4) The (activation /inhibition/saturation) point of an enzyme is reached when all active sites have bound substrate molecules. Answer: saturation Bloom's Taxonomy: Comprehension Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.6 5) When a noncompetitive inhibitor molecule binds to a(n) (active/allosteric/substrate) site on an enzyme, the shape of the active site changes so that the substrate molecules can no longer bind. Answer: allosteric Bloom's Taxonomy: Knowledge Section: Basic Chemical Reactions Underlying Metabolism Learning Outcome: 5.6 6) Beta-oxidation of fatty acids produces (acetic acid/acetyl-CoA/glycerol). Answer: acetyl-CoA Bloom's Taxonomy: Knowledge Section: Other Catabolic Pathways Learning Outcome: 5.18 7) Electrons are transferred in the Krebs cycle in the form of (oxygen/hydrogen) atoms to NAD+ and FAD. Answer: hydrogen Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.9 8) The purpose of electron transport is to create a proton (concentration/gradient/pump) across a membrane that can then be used to make ATP. Answer: gradient Bloom's Taxonomy: Knowledge Section: Carbohydrate Catabolism Learning Outcome: 5.12

15 Copyright © 2018 Pearson Education, Inc.

9) Anaerobic respiration involves the use of molecules other than oxygen as the final electron (acceptor/donor) in an electron transport chain. Answer: acceptor Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.10 10) Laboratory fermentation tests often include a pH indicator because many bacteria produce (O2/bases/acids) as they ferment carbohydrates. Answer: acids Bloom's Taxonomy: Comprehension Section: Carbohydrate Catabolism Learning Outcome: 5.16 11) Amino acids are converted to substrates of the Krebs cycle by (...