Exam #2

  1. Propionibacterium is used in the fermentation process that produces Swiss cheese. The characteristic flavor of this cheese is due to the ____, and the holes in the cheese are due to the ____ produced.
    propionate, CO2
  2. The symbiotic relationship between the obligate proton reducers and the hydrogen utilizers is called a _______association. It is also called interspecies hydrogen transfer.
    syntrophic
  3. Most fermenting bacteria make most or all of their ATP via ____ ____ ____, and they create a Dp (needed for solute transport, motility, etc) by reversing the membrane-bound
    substrate level phosphorylation
  4. All the bacteria can do aerobic respiration. (T/F)
    False
  5. Fermentation is very efficient for making ATP. (T/F)
    False
  6. The H2 gas can be sometimes a fermentation product. (T/F)
    True
  7. Bacteria prefer fermentation to anaerobic respiration. (T/F)
    False
  8. Bacteria make only one fermentation product at a given time. (T/F)
    False
  9. Fermentation happens in the cell membrane as well as in the cytosol. (T/F)
    False
  10. Bacteria do fermentation for making NADH as well as ATP. 2NADH, byproduct…bacteria whether make ATP, fermentation is to make ATP without NADH (T/F)
    False
  11. EF-G is responsible for chain translocation during peptide synthesis. What is the energy source for this process?
    GTP hydrolysis
  12. Messenger RNAs are translated by several ribosomes (typically around 50) in series and the complex ribosomes attached to an mRNA is a _____.
    Polysome
  13. In bacteria, several genes can be transcribed into a single mRNA. How do you call a cluster of such co-transcribed genes?
    Operon
  14. _____ refers to the phenomenon in ploycistronic mRNAs in which a block in the translation of an upstream gene can prevent transcription of a downstream gene.
    Polarity
  15. . In the process of protein synthesis,____ are responsible for placing the correct amino acids into the polypeptide sequence. For this reason, ___ are called adaptor molecules.
    tRNA, tRNA
  16. Transcriptional activators bind to specific sites in the DNA _____ of the RNA polymerase and make contact with the RNA polymerase while enhancing its activity. Repressors bind _____ of the RNA polymerase (in the operator region) and block progression of the RNA polymerase.
    Upstream, Downstream
  17. All the operons regulated by a single transcriptional factor are collectively called a ____
    regulon
  18. An operon consists of two or more genes that are co-transcribed into a ______ mRNA from a single promoter at the beginning of the first gene
    Polycistronic
  19. A sigma factor is responsible for recognition of certain promoter(s). Sometimes bacteria need to regulate the activities of sigma factors. One way that bacteria control the activities of its sigma factors is by using _____ that bind to them and inhibit their activity.
    Anti-Sigma Factor
  20. Factor-independent termination of RNA polymerase action ____ occurs just after the RNA polymerase transcribes a self-______ sequence of bases
    transcription, complementary
  21. Transcription initiation takes place at the ____ site. Within the _____ region, there are two critical sties for transcription to occur: -10 and -35 regions.
    Promoter, Promoter
  22. Transcription is to make RNA from DNA. There are three stages in transcription. What are those?
    Initiation, Elongation, Termination
  23. In order for a transcriptional activator to work, the interaction between the protein and RNA polymerase is a must. (T/F)
    True
  24. Transcriptional activator helps RNA polymerase to transcribe and repressor inhibits RNA polymerase from transcription. (T/F)
    True
  25. Sigma factor of RNA polymerase is required to recognize a promoter. In a bacterium, there is only one sigma factor. (T/F)
    False
  26. Transcription is carried out by RNA polymerase. (T/F)
    True
  27. A tRNA should be able to recognize both amino acid and a codon present in mRNA. (T/F)
    True
  28. Since there are 20 different amino acids, the total number for the type of tRNAs is 20. (T/F)
    False
  29. Peptide bond formation is catalyzed by a peptidyltransferase in the ribosome. Such activity is in an RNA, not in a protein. (T/F)
    True
  30. In the mRNA sequence, there is a site that ribosome preferentially binds. (T/F)
    True
  31. If you have an mRNA the size of which is 300 bp, then you will have a protein the size of which is 100 amino acids. (T/F)
    False
  32. If you are able to see the sequences of all the proteins inside a bacterium, you will find always methionine at the N-termini of all those proteins. (T/F)
    False
  33. The site of septum formation for bacterial cell division is determined by two separate systems called ____ ____ and ____
    Nucleoid Occlusion,   Min
  34. A single cell that has 30-min doubling time will become ___ cells after 2 hrs.
    24 = 16  (120/30)
  35. A single cell will become ____ cells after 10 generations.
    210 = 1024
  36. Several of the cell division genes are called fts genes, and fts stands for ____ ____ ____ phenotypes
    filamentous temperature sensitive
  37. Preferential growth on one carbon source before growth on a second carbon source is called ____ growth
    diauric
  38. Growth in batch bacterial culture can progress through a ___ and ___ to ____ phase.
    lag, log, stationary
  39. In the chemostat the concentration of the limiting nutrient in the reservoir is kept very ____ so that growth is limited by the availability of the nutrient.
    low
  40. The most commonly used measurements of growth are ___, ____ cell counts, and ___ weight measurement.
    living, viable, dry
  41. When bacterial cells sense amino acid starvation inside the cell (of course because of lack of food outside), the cells should not make ribosomes at the expense of energy. So, there must be a ribosome regulation mechanism in the bacterial cells. (T/F)
    True
  42. Faster growing bacterial cells are bigger compared to slower growing counterparts. (T/F)
    True
  43. Bacterial ribosomes can change the rate of protein synthesis in response to growth situation. (T/F)
    False
  44. Cells entering stationary phase become more resistance to environmental stresses such as high temperature, osmotic stress, and certain chemicals. (T/F)
    False
  45. Under overwhelming environmental stresses (such as heat, osmotic stress), bacterial become less active. (T/F)
    True
  46. Most bacteria can be cultured in the laboratory. (T/F)
    False
  47. Most bacteria divide by fission. (T/F)
    True
  48. The advantages of a multienzyme complex in the cytosol is that it facilitates the _____ of metabolites, thus increasing the efficiency of catalysis.
    channeling, example pyro
  49. Swimming bacteria are capable of _____ responses
    tactic
  50. Bacteria excrete enzymes outside of their cells to build either cell wall structure or outer membrane structure. (T/F)
    False, Enzymes needed to break down food.
  51. Bacteria have nuclei. (T/F)
    False
  52. 16s rRNA which has been used for phylogeny is one component of ribosome. (T/F)
    True
  53. LPS is anchored at cell membrane. (T/F)
    False, its located on the outer membrane
  54. In many cases, LPS has important role in pathogens' virulence, so one of its components is often called O antigen(s). (T/F)
    True
  55. Gram-positive cell wall is thicker than Gram-negative counterpart and this is the basis for Gram staining. (T/F)
    True
  56. Bacterial swimming and swarming involve movement. However, swimming is for individual one and swarming is for the movement of a population. (T/F)
    True
  57. Bacterial pili are anchored at cell membrane. (T/F)
    False
  58. Bacterial flagella are anchored at outer membrane. (T/F)
    False
  59. Bacterial flagella use proton potential for its energy source. (T/F)
    True
  60. There are three characterized CO2 fixation pathways used for autotrophic growth. The Calvin cycle is the only one in the ___ biosphere
    aerobic
  61. In methanogens, methyl coenzyme M reductase catalyzes the final step for CH4 generation. For this reaction, the enzyme requires coenzyme F430, which is a _____-tetrapyrrole H2 gas is used by methanogens to fix CO2 (all gas molecules) co-bounded to enzyme to trap to gas, prosethic group is hung on.
    nickel containing
  62. In CO2 fixing bacteria using the acetyl-CoA pathway, this enzyme is crucial because it is capable of reducing CO2 to the level of carbon monoxide and catalyzing its condensation with bound methyl and CoA to form acetyl-CoA. This enzyme is _______.
    carbon monoxide dehydrogenase
  63. Many aerobic bacteria can grow on C1 compounds other than CO2. These bacteria are called _____.
    methylotrophs
  64. 70% of the atmospheric methane on earth is produced by _____.
    methanogens
  65. Three prokaryotic CO2 fixation mechanisms are ____ cycle, the _____ pathway, and ___ ____ ____ pathway.
    Calvin, acetyl CoA, reductive tricarboxylic acid
  66. Bacteria do fermentation in order to grow on methane (methane is a fermentation by product). (T/F)
    False
  67. Bacteria do CO2 assimilation for energy generation. (T/F)
    False
  68. Only archaea can grow on C1 compounds such as methane, methanol, formaldehyde, formate methylamine. (T/F)
    False
  69. Only bacteria can do CO2 fixation. (T/F)
    False
  70. Among all lives on earth, only archaea can produce methane. (T/F)
    True
  71. CO2 can be used for energy generation by acting as an electron acceptor, but not electron donor. (T/F)
    True
  72. Mutations in the dnaQ (mutD) gene, which codes for a ______ subunit in the DNA polymerase III holoenzyme, result in greatly increased rates of spontaneous mutations.
    3' exonuclease
  73. In E. coli the two replication forks that begin at _____ and polymerize bi-directionally stop in a region of the chromosome opposite _____, called _____, the termination region.
    Ori C, Ori C, Ter
  74. During DNA replication, you will find several copies of short DNA fragments in the lagging strand, but you don't see such stuff in the leading strand. What is this called?
    Okazaki fragments.
  75. At the replication fork the DNA templates are _____; that is, one strand is 5' to 3' and the other strand is 3' to 5'.
    anti-parallel
  76. DNA replication takes place in a DNA-synthesizing "factory" called a ____, which consists of an assemblage of enzymes and proteins that will soon be described.
    ribosomal
  77. The DNA in a typical bacterium exists as a covalently closed circle of a right-handed double helix that may be ____ to ____ times longer than the cell.
    500, 600  (supercoiling is required)
  78. RNA polymerase prefers some DNA sites for it to bind. (T/F)
    True
  79. In bacteria, every DNA base in the chromosome is transcribed into RNA. (T/F)
    False
  80. Our best friend E. coli is so smart that during DNA replication it can distinguish between original old strand and newly made copy strand. (T/F)
    True
  81. DNA polymerase always elongates DNA in 5' --> 3' direction. (T/F)
    True
  82. DNA polymerase always requires a small RNA or DNA (termed primer) to initiate chain elongation. (T/F)
    True
  83. The chromosomes of most bacteria are circular. (T/F)
    True
  84. Mutations in DNA always lead to a change in phenotype. T/F
    False
Author
EricaAwes
ID
325465
Card Set
Exam #2
Description
Microbial Physiology
Updated