Test Bank Answers 3rd Edition Ch.7 Microbial Metabolism

Microbiology Fundamentals: A Clinical Approach, 3e (Cowan)

Chapter 7 Microbial Metabolism

1) All of the chemical reactions of the cell are called ________.

A) catabolism

B) redox reactions

C) phosphorylation

D) metabolism

E) cellular respiration

2) The breakdown of peptidoglycan to N-acetylmuramic acid, N-acetylglucosamine, and peptides is an example of ________.

A) anabolism

B) catabolism

C) phosphorylation

D) fermentation

E) synthesis

3) Enzymes are ________.

A) broken down in reactions that require energy input

B) proteins that function as catalysts

C) used up in chemical reactions

D) not needed for catabolic reactions

E) All of the choices are correct

4) Formation of peptide bonds between amino acids to build a polypeptide would be called ________.

A) anabolism

B) phosphorylation

C) fermentation

D) exergonic

E) glycolysis

5) Reactants are converted to products by ________.

A) enzymes releasing energy

B) breaking and forming bonds

C) enzymes binding to reactants

D) reactants releasing energy

E) None of the choices are correct

6) Each of the following is true of enzymes except ________.

A) they can be used over and over

B) they may or may not require cofactors

C) their active site is specific to the substrate

D) they increase the initial energy required for a reaction to start

E) All of the choices are true of enzymes

7) The cell's metabolic reactions involve the participation of ________ that lower the activation energy needed for the initiation of a reaction.

A) cofactors

B) vitamins

C) enzymes

D) ATP

E) coenzymes

8) An apoenzyme is ________.

A) part of a simple enzyme

B) also called a coenzyme

C) the protein part of a holoenzyme

D) often an inorganic metal ion

E) an RNA molecule

9) A holoenzyme is a combination of a protein and one or more substances called ________.

A) substrates

B) apoenzymes

C) catalysts

D) cofactors

E) reactants

10) Important components of coenzymes are ________.

A) vitamins

B) metallic ions

C) active sites

D) substrates

E) ribozymes

11) Enzymes that are only produced when substrate is present are termed ________.

A) exoenzymes

B) endoenzymes

C) constitutive enzymes

D) induced enzymes

E) conjugated enzymes

12) Enzymes that hydrolyze a peptide bond are called ________.

A) phosphotransferases

B) oxidoreductases

C) peptidases

D) aminotransferases

E) ligases

13) During aerobic cellular respiration, the final electron acceptor is ________.

A) pyruvic acid

B) oxygen

C) nitrate

D) cytochrome c

E) FAD

14) Enzymes that are always present, regardless of the amount of substrate, are ________.

A) apoenzymes

B) axoenzymes

C) constitutive enzymes.

D) regulated enzymes

E) endoenzymes

15) When enzyme action stops due to a buildup of end product, this control is called ________.

A) feedback inhibition (negative feedback)

B) competitive inhibition

C) enzyme induction

D) enzyme repression

E) None of the choices are correct.

16) Each of the following are denaturing agents except ________.

A) high temperature

B) low temperature

C) high pH

D) low pH

E) All of the choices are correct

17) Feedback inhibition, a negative feedback mechanism that regulates enzymes, is best described as ________.

A) substrate binding to DNA, blocking enzyme transcription

B) product binding to DNA, blocking enzyme transcription

C) substrate binding to enzyme in noncompetitive site

D) product binding to enzyme in noncompetitive site

E) None of the choices are correct.

18) Metabolic pathways that regenerate their starting point are called ________ pathways.

A) linear

B) bidirectional

C) convergent

D) cyclic

E) divergent

19) When the product of reaction A becomes the reactant of reaction B, the metabolic pathway is ________.

A) linear

B) bidirectional

C) convergent

D) cyclic

E) divergent

20) Most electron carriers are ________.

A) coenzymes

B) enzymes

C) hydrogens

D) inorganic phosphates

E) polysaccharides

21) Exergonic reactions ________.

A) include synthesis of large carbohydrates

B) only occur in heterotrophs

C) release energy

D) do not occur in anaerobic cellular respiration

E) occur when ADP binds to inorganic phosphate to form ATP

22) In the electron transport chain, the collective, captured energy released by electrons is used to phosphorylate ________.

A) ATP

B) ADP

C) pyruvic acid

D) oxygen

E) NAD

23) In addition to electrons, which of the following can also be transferred, exchanging energy in the process?

A) ADP

B) Glucose

C) Carbon

D) Hydrogen

E) Carbon dioxide

24) FAD, NAD, and coenzyme A are all ________ carriers.

A) hydrogen

B) electron

C) ATP

D) hydrogen and electron

E) None of the choices are correct.

25) Which of the following is not true regarding glycolysis?

A) It occurs without oxygen

B) It ends with the formation of pyruvic acid

C) It occurs during fermentation

D) It degrades glucose to CO2 and H2O

E) It involves the reduction of NAD+

26) Glycolysis ________.

A) uses 2 ATPs, produces 2 ATPs, and requires oxygen

B) uses 2 ATPs, produces 4 ATPs, and requires oxygen

C) uses 2 ATPs, produces 4 ATPs, without using oxygen

D) uses 2 ATPs, produces 2 ATPs, without using oxygen

E) None of the choices are correct.

27) The formation of citrate from oxaloacetate and an acetyl-CoA begins ________.

A) glycolysis

B) the electron transport system

C) the Krebs cycle

D) fermentation

E) oxidative phosphorylation

28) Which of the following is not involved in the step that occurs between glycolysis and the Krebs cycle?

A) NADH is formed

B) CO2 is released 

C) Coenzyme A attaches to an acetyl group

D) Pyruvic acid accepts electrons from NADH

29) In aerobic respiration, the majority of the reduced coenzyme NADH is produced in ________.

A) glycolysis

B) the Krebs cycle

C) the electron transport chain

D) photosynthesis

E) the cell membrane

30) In bacterial cells, the electron transport system is located in the ________.

A) cell membrane

B) mitochondria

C) chloroplasts

D) ribosomes

E) cytoplasm

31) Each NADH that enters the electron transport system gives rise to a maximum of ________ ATP.

A) 2

B) 3

C) 24

D) 36

E) 38

32) As the electron transport carriers shuttle electrons, they actively pump ________ into the outer membrane compartment setting up a concentration gradient called the proton motive force.

A) ATP

B) phosphate

C) hydrogen ions

D) oxygen

E) NADH

33) The carrier molecules in the electron transport chain that have a tightly bound metal atom responsible for accepting and donating electrons are ________.

A) NAD+

B) FAD

C) NADH

D) cytochromes

E) flavoproteins

34) Each FADH2 from the Krebs cycle enters the electron transport system and gives rise to a maximum of ________ ATP(s).

A) 1

B) 2

C) 3

D) 4

E) 5

35) NADH and FADH2 molecules are oxidized in which step of the aerobic respiration process?

A) Electron transport system

B) Krebs cycle

C) Glycolysis

D) Preparation for Krebs cycle

36) During which phase of cellular respiration is the majority of ATP formed?

A) Krebs cycle

B) Glycolysis

C) Processing of pyruvic acid for the Krebs cycle

D) Electron transport

E) All phases produce the same number of ATP molecules.

37) In bacterial cells, when glucose is completely oxidized by all the pathways of aerobic cellular respiration, what is the maximum number of ATP generated?

A) 2 ATP

B) 3 ATP

C) 24 ATP

D) 38 ATP

E) 42 ATP

38) How many carbon dioxide molecules are produced by the complete aerobic breakdown of one glucose molecule?

A) 2

B) 3

C) 4

D) 5

E) 6

39) Which of the following is not true of anaerobic respiration?

A) Involves glycolysis

B) Generates some ATP

C) Utilizes an electron transport system

D) Uses the same final electron acceptor as aerobic respiration

40) Reduction of nitrogen-oxygen ions, such as nitrate, by some bacteria is called ________.

A) aerobic respiration

B) denitrification

C) nitrification

D) fermentation

E) deamination

41) The reactions of fermentation function to produce ________ molecules for use in glycolysis.

A) pyruvic acid

B) ATP

C) NAD+

D) NADH

E) glucose

42) When glucose is broken down by glycolysis during bacterial fermentation, how many ATP are generated?

A) 2 ATP

B) 3 ATP

C) 24 ATP

D) 36 ATP

E) 38 ATP

43) Fermentation ________.

A) requires an organic electron acceptor

B) requires oxygen

C) only occurs in aerobic organisms

D) can be equivalent to aerobic respiration in ATP production

E) is the same as anaerobic respiration

44) Deamination is the removal of a(n) ________ group in proteins.

A) carboxyl

B) amino

C) phosphate

D) hydroxyl

E) glycerol

45) The property of organisms to integrate catabolic and anabolic pathways to improve cell efficiency is called ________.

A) metabolism

B) amphibolism

C) anabolism

D) catabolism

E) biosynthesis

46) The principal sites of amphibolic interaction occur during ________.

A) glycolysis and photosynthesis

B) the Krebs cycle and electron transport system

C) glycolysis and the Krebs cycle

D) fermentation and the Krebs cycle

E) fermentation and glycolysis

47) Fatty acids can be converted to acetyl-CoA for entering the Krebs cycle by the process of ________.

A) amination

B) deamination

C) phosphorylation

D) beta oxidation

E) gluconeogenesis

48) ATP molecules are catalysts that lower the activation energy needed to initiate a reaction.

49) Building block molecules for biosynthetic pathways come from the cell's catabolic pathways and from the environment.

50) Denaturing an apoenzyme will destroy the three-dimensional shape of the protein, making it nonfunctional.

51) ATP is composed of deoxyribose, adenine, and three phosphate groups.

52) ATP synthase is a complex enzyme needed for oxidative phosphorylation.

53) All aerobic bacterial species have identical electron acceptors in their electron transport systems.

54) The fermentation process always produces alcohol as at least one of its products.

55) Oxygen-containing ions are used by some bacteria as final electron acceptors.

56) Microbes can utilize only carbohydrates for energy production.

57) In a bacterial cell, synthesis of an essential amino acid would take place continually unless the amino acid was abundant in the growth media, in which case ________.

A) the genes that code for the enzymes that catalyze the synthesis of the amino acid would be repressed

B) the genes that code for the enzymes that catalyze the synthesis of the amino acid would be induced

C) the enzymes that catalyze the reactions to hydrolyze the amino acid would be repressed

D) the enzymes that catalyze the reactions to hydrolyze the amino acid would be induced

58) In a bacterial cell, the genes that code for enzymes that catalyze the hydrolysis of an unusual carbohydrate source would be turned off unless that carbohydrate was the only fuel source available in the media, in which case ________.

A) the genes coding for the hydrolytic enzymes would be induced

B) the genes coding for the hydrolytic enzymes would be repressed

C) the genes coding for the hydrolytic enzymes would be constitutive

D) the enzymes would be denatured

59) A metabolic pathway begins as a series of linear reactions then, at a specific point in the pathway, two reactants are produced, each of which proceed in a linear, yet different chain of reactions.  This is an example of a ________.

A) divergent pathway

B) convergent pathway

C) cyclical pathway

D) linear pathway

60) Catabolic reactions are coupled with ATP ________, whereas anabolic reactions are coupled with ATP ________.

A) synthesis; hydrolysis

B) hydrolysis; synthesis

C) amphibolism; repression

D) deamination; beta oxidation

61) The complete combustion of methane is written CH4 + 2O2 → CO2 + 2H2O. In this reaction, the methane is ________ and the oxygen is ________.

A) oxidized; reduced

B) reduced; oxidized

C) phosphorylated; oxidized

D) endergonic; exergonic

62) In bacterial cells, the electron carriers NAD+ and FAD are found in the ________, whereas the cytochromes are located in the ________.

A) cytoplasm; cell membrane

B) mitochondria; cytoplasm

C) cell membrane; cytoplasm

D) cell membrane; inner mitochondrial membrane

63) The hydrolysis of two ATP molecules at the start of glycolysis is analogous to ________.

A) striking a match to ignite a pile of burning firewood

B) combining butter, sugar, flour and eggs to make a cake

C) building a house

D) kicking a soccer ball and scoring a goal

64) Intermediates in the glycolysis pathway feed into additional pathways that make amino acids and complex carbohydrates. These latter pathways are ________.

A) biosynthetic and endergonic

B) hydrolytic and exergonic

C) biosynthetic and exergonic

D) hydrolytic and endergonic

65) Anabolic pathways are associated with a net gain of ATP, whereas catabolic pathways, for example, glycolysis, are associated with a net ATP breakdown.

66) Which of the following does not reflect anabolism?

A) Beta oxidation of fatty acids to acetyl CoA.

B) Enzyme production from amino acids.

C) DNA replication from nucleotides.

D) Fatty acid assimilation to form lipids.

67) An example of amphibolism is when ________.

A) pyruvate is converted to acetyl CoA to enter the Krebs cycle, and is also used as a precursor for amino acid production

B) acetyl CoA enters the Krebs cycle, and is also used for fatty acid production

C) intermediates of glucose oxidation are further oxidized during glycolysis, and are also harnessed for the production of complex carbohydrates

D) All of the above are examples of amphibolism

NCLEX Prep - Test Bank Question:  Please read the clinical scenario, and then answer the questions that follow to become familiar with the traditional NCLEX question format.

A patient with anorexia nervosa is admitted to the hospital for medical treatment. The patient presents with severe malnutrition and evidence of organ dysfunction. Labs are drawn and continuous intravenous (IV) fluids are initiated.

68) The RN prepares to initiate IV fluid therapy for the patient. Knowing the importance of cellular energy production, which of the following maintenance IV fluids would be most appropriate for the physician to order? 

A) 0.9% sodium chloride

B) Lactated ringers

C) 0.45% sodium chloride

D) 0.9% sodium chloride with dextrose

69) The RN educates the patient and her family about cellular metabolism. Which of the following processes is common to fermentation, anaerobic respiration, and aerobic respiration? 

A) Glycolysis

B) The Krebs cycle

C) The electron transport system

D) Glycosylation

70) The RN is familiar with ATP production in bacterial and eukaryotic cells. How many ATP per glucose molecule would aerobic respiration yield in the patient's cells?

A) 2 ATP

B) 36 ATPs

C) 38 ATP

D) ATP yield is unpredictable.

71) The RN instructs the patient that although bacterial cells can also undergo aerobic respiration, they differ from eukaryotic cells in that ________.

A) they make less ATP in this process than eukaryotic cells

B) the Krebs cycle takes place in the mitochondrion in these cells

C) glycolysis takes place in the mitochondrion in these cells

D) the electron transport chain is present in the plasma membrane of these cells

NCLEX Prep - Test Bank Question:  Please read the clinical scenario, and then answer the questions that follow to become familiar with the traditional NCLEX question format.

A newborn infant screening yields a positive result for biotinidase deficiency. The RN prepares education for the patient's parents regarding the role of enzymes in metabolism and this enzyme deficiency disorder.

72) Which of the following statements, by the patient's mother, best represents an understanding of metabolism?  

A) Metabolism involves the production of enzymes.

B) Metabolism involves all chemical reactions and physical workings of the cell.

C) Metabolism involves the consumption of energy for workings of the cell.

D) Metabolism involves the production of energy for workings of the cell.

73) All of the following are true of enzymes except ________.

A) enzymes increase the rate of a chemical reaction

B) enzymes are not part of the products of a chemical reaction

C) enzymes create a chemical reaction

D) enzymes are not consumed in a chemical reaction

74) Inborn errors of metabolism ________.

A) are caused by infectious agents

B) produce very specific signs and symptoms, making them easy to diagnose

C) cannot be diagnosed by DNA testing

D) may not become evident until adulthood

75) Based upon knowledge of enzymes and metabolic processes, which of the following outcomes should the parents expect if the deficiency is not treated?  

A) No effect on the patient's health

B) Reduced immunity in adulthood in the patient

C) Mildly impaired vision in the patient

D) Permanent damage to organ systems and/or death of the patient

NCLEX Prep - Test Bank Question:  Please read the clinical scenario, and then answer the questions that follow to become familiar with the traditional NCLEX question format.

A 67-year-old patient with severe sepsis undergoes a full infectious workup upon admittance to the intensive care unit. Cultures of urine, blood, sputum, and cerebral spinal fluid are obtained. The cultures do not yield a specific organism, so further analysis of the sample is done to determine the characteristics of the microorganism. The organism's metabolic processes are analyzed in the lab.

76) The organism is found to grow throughout the entire tube of broth media. Which of the following terms best describes the oxygen requirement of this organism?  

A) Obligate aerobe

B) Microaerophile

C) Facultative anaerobe

D) Obligate anaerobe

77) The organism sample is further tested and found to grow in the absence of oxygen. Which of three main pathways of catabolism may this organism utilize to produce energy under these circumstances?

A) Aerobic respiration and fermentation

B) Anaerobic respiration and aerobic respiration

C) Fermentation and anaerobic respiration

D) Aerobic respiration, anaerobic respiration, and fermentation

78) Biochemical testing reveals that the organism further reduces nitrite to produce nitrous oxide. Based on this byproduct, which of the following is the most likely catabolic pathway utilized by this organism?

A) Aerobic respiration

B) Anaerobic respiration

C) Fermentation

D) Aerobic respiration, anaerobic respiration, and fermentation can all lead to the production of nitrous oxide

79) Which of the following statements properly characterizes the ATP yield from anaerobic respiration?

A) Anaerobic respiration produces less ATP per glucose molecule than aerobic respiration at maximum net yield.

B) Anaerobic respiration at maximum net yield produces more ATP per glucose molecule than fermentation.

C) Anaerobic respiration produces 2-36 ATPs per glucose molecule.

D) All of the choices are correct.