Micro Chapter 3

62. Bacterial and archaeal ribosomes are known as _____ ribosomes, based on their sedimentation coefficient. A. 50S B. 30S C. 80S D. 70S

D. 70S

90. Which of the following is a characteristic of active transport? A. Saturable uptake rate. B. Use of ATP or a proton gradient as a source of metabolic energy. C. Can move materials against a concentration gradient. D. All of the choices.

D. All of the choices.

91. The movement of molecules across a membrane from an area of lower concentration to an area of higher concentration with the expenditure of energy is called A. facilitated diffusion. B. osmosis. C. passive diffusion. D. active transport.

D. active transport.

63. The type III bacterial protein secretion machinery: A. has a needlelike structure through which proteins are secreted. B. includes structural features that may be evolutionarily related to the basal bodies of bacterial flagella. C. is found in gram-negative bacteria. D. all of the choices are correct.

D. all of the choices are correct.

50. The cytoplasmic membrane of bacteria A. retains the cytoplasm and its contents. B. acts as a selectively permeable barrier, allowing some molecules to pass while preventing the movement of others. C. is the major site of ATP synthesis in aerobes. D. all of the choices.

D. all of the choices.

52. Which of the following is/are true of capsules? A. They help bacteria escape phagocytosis by host cells. B. They retain water and help prevent desiccation of the bacteria. C. They prevent entry of many bacterial viruses. D. all of the choices.

D. all of the choices.

67. Twitching or gliding motility involves A. type IV pili. B. axial fibrils. C. movement of slime. D. both type IV pili and movement of slime can be involved in twitching or gliding motility.

D. both type IV pili and movement of slime can be involved in twitching or gliding motility.

70. Which of the following is not considered a macronutrient? A. carbon (C) B. calcium (Ca) C. potassium (K) D. cobalt (Co)

D. cobalt (Co)

42. The term used to describe bacteria that are intermediate in shape between spherical and rod-shaped is A. cocci. B. bacilli. C. vibrio. D. coccobacilli.

D. coccobacilli.

89. Which of the following processes can be used to bring nutrients into a cell against a concentration gradient? A. Active transport. B. Facilitated diffusion. C. Passive diffusion. D. Active transport and facilitated diffusion.

A. Active transport.

58. All of the following statements about the periplasmic space are true except: A. It is found only in gram-positive bacteria. B. It is located between the plasma membrane and outer membrane of gram-negative bacteria. C. It contains hydrolytic enzymes and binding proteins involved in nutrient acquisition. D. All of the above are true.

A. It is found only in gram-positive bacteria.

56. Lipids with polar and nonpolar ends are said to be A. amphipathic. B. amphibolic. C. bilateral. D. none of the choices.

A. amphipathic.

21. (p. 77) Which of the following structures is NOT found in an endospore? A. capsule B. coat C. core D. exosporium

A. capsule

49. The term used to describe bacteria that have a spherical shape is A. coccus. B. bacillus. C. vibrio. D. coccobacillus.

A. coccus.

92. The movement of molecules across a membrane from an area of higher concentration to an area of lower concentration with the use of a carrier molecule embedded in the membrane is called A. facilitated diffusion. B. osmosis. C. passive diffusion. D. active transport.

A. facilitated diffusion.

66. Chemotaxis is a process by which bacteria A. move toward an attractant or away from a repellent. B. avoid phagocytosis. C. respond metabolically to the presence of autoinducer molecules. D. move on solid surfaces by means of type IV fimbriae.

A. move toward an attractant or away from a repellent.

53. Proteins that are loosely associated with the cytoplasmic membrane are called __________ proteins. A. peripheral B. integral C. external D. internal

A. peripheral

81. A wide variety of microorganisms are commercially used to manufacture _________ for human consumption. A. vitamins B. sugars C. fatty acids D. none of the choices

A. vitamins

41. The concept of a prokaryote was first fully outlined in 1962 by A. Watson and Crick. B. Stanier and Van Niel. C. Hersey and Chase. D. Gilbert and Cech.

B. Stanier and Van Niel.

48. The term used to describe bacteria that are rod shaped is A. coccus. B. bacillus. C. vibrio. D. coccobacillus.

B. bacillus.

60. Sortase is a protein enzyme of bacteria that A. plays a key role in directing proteins to the periplasm. B. catalyzes covalent attachment of some surface proteins to peptidoglycan. C. directs secretion of proteins across the outer membrane. D. functions by transporting flagellum proteins to their extracellular site of assembly.

B. catalyzes covalent attachment of some surface proteins to peptidoglycan.

54. Proteins that are embedded within the cytoplasmic membrane and not easily extracted are called __________ proteins. A. peripheral B. integral C. external D. internal

B. integral

57. Although penicillin inhibits peptidoglycan synthesis, bacterial cells will continue to grow normally in the presence of penicillin in a(n) __________ environment. A. hypotonic B. isotonic C. hypertonic D. nonpolar

B. isotonic

71. Which of the following is not considered a micronutrient? A. manganese (Mn) B. magnesium (Mg) C. zinc (Zn) D. copper (Cu)

B. magnesium (Mg)

59. Which of the following protects bacteria from lysis in dilute solutions and helps to determine their cellular morphology or shape? A. plasma membrane B. peptidoglycan C. capsule D. gas vacuoles

B. peptidoglycan

55. Shrinkage of the plasma membrane away from the cell wall when the bacterium is placed in a hypertonic environment is called A. osmolysis. B. plasmolysis. C. hydrolysis. D. hypertonolysis.

B. plasmolysis.

43. Bacterial cells that are variable in shape are called A. vibrio. B. pleomorphic. C. coccobacilli. D. hyphal.

B. pleomorphic.

46. Rigid bacteria with a helical cell shape are called A. vibrios. B. spirilla. C. spirochetes. D. coccobacilli.

B. spirilla.

95. __________ membranes allow some molecules to pass but not others. A. Permeable B. Inverted monolayer C. Selectively permeable D. Impermeable

C. Selectively permeable

61. Which of the following is not true of bacterial plasmids? A. They can replicate independently of the chromosome. B. They may carry genes for drug resistance. C. They are required for host growth and/or reproduction. D. They may carry genes that enhance survival of the bacterium under certain conditions.

C. They are required for host growth and/or reproduction.

94. Nutrients can be concentrated from dilute solutions by A. pinocytosis. B. endocytosis. C. active transport and group translocation. D. electron transport.

C. active transport and group translocation.

64. Export of flagellin subunits is mediated by A. an apparatus in the basal body of the flagellum that is related to the type II secretion pathway. B. the type I secretion pathway. C. an apparatus in the basal body of the flagellum that is related to the type III secretion pathway. D. none of the above.

C. an apparatus in the basal body of the flagellum that is related to the type III secretion pathway.

69. Elements that are required in relatively large amounts by microorganisms are called A. multivitamins. B. meganutrients. C. macronutrients. D. macromolecules.

C. macronutrients.

93. The movement of molecules from an area of higher concentration to an area of lower concentration without the participation of specific carrier molecules is called A. facilitated diffusion. B. osmosis. C. passive diffusion. D. active transport.

C. passive diffusion.

65. The power used by most bacterial flagellar motors is produced by A. synthesis of glucose. B. ATP hydrolysis. C. proton motive force (PMF). D. all of these.

C. proton motive force (PMF).

45. Flexible bacteria with a helical shape are called A. vibrios. B. spirilla. C. spirochetes. D. coccobacilli.

C. spirochetes.

44. Square planar arrangement of cells that forms when round bacteria remain attached to each other during reproduction are called A. streptococci. B. staphylococci. C. tetrads. D. sarcinae.

C. tetrads.

47. The term used to describe bacteria that are shaped like curved rods is A. coccus. B. bacillus. C. vibrio. D. coccobacillus.

C. vibrio.

68. Endospores represent a challenge to the fields of industrial and medical microbiology because A. they are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive. B. endospore-forming organisms are often dangerous pathogens. C. endospores are significantly smaller than vegetative cells. D. endospores are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive, and endospore-forming organisms are often dangerous pathogens.

D. endospores are resistant to harsh environments, thus allowing survival of endospore-forming organisms under conditions in which non-endospore-forming cells would not survive, and endospore-forming organisms are often dangerous pathogens.

51. The lipopolysaccharide (LPS) that is found in the outer membrane of gram-negative bacteria is also known as A. exotoxin. B. teichoic acid. C. murein. D. endotoxin.

D. endotoxin.

18. (p. 52) You discover a new transport system used by a newly discovered bacterial species. The sugars that are transported using this system are phosphorylated as they enter the bacterial cell. You would describe this transport system as a(n) _____. A. facillitated diffusion B. micronutrient regulator C. passive diffusion D. group translocation

D. group translocation

79. Which of the following is not a major class of growth factors? A. amino acids B. purines and pyrimidines C. vitamins D. nucleic acids

D. nucleic acids