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Microbiology > Class Exam 2 > Flashcards

Class Exam 2 Flashcards

1
Q

what was lacking in the atmosphere of early earth?

A

No O2

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2
Q

what was early earths atmosphere made of?

A

Methane (CH4), CO2, N2, NH3

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3
Q

what had to happen before liquid water could exist on early earth?

A

the planet needed to cool down

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4
Q

how many billion years ago did liquid water start to appear on earth?

A

4.3 billion years ago

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5
Q

what is it called When “organisms metabolize substances, they selectively utilize lighter isotopes of an element”.

A

Fractionation

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6
Q

C isotopes in limestone point to what evidence of microbial energy production?

A

Evidence of photosynthesis

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7
Q

SO4^2- reducing bacteria preferentially use what isotope of sulfur?

A

32S not 34S

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8
Q

Explain the “Surface Origin Hypothesis”

A

Contends that the first membrane-enclosed, self- replicating cells arose out of primordial soup rich in organic and inorganic compounds in ponds on Earth’s surface.

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9
Q

Explain the “Stanley Miller and Harold Urey (1953) experiment”.

A
  • H2, water, NH3, CH4 into a closed system
  • Electrical discharge (lightning) was used on the system
  • Yielded amino acids (building blocks of life)
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10
Q

explain the “Origin of Cellular Life:

Subsurface Origin” theory.

A

life originated at hydrothermal springs

on ocean floor.

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11
Q

RNA is the_________ of ATP, NAD+, coenzyme A

A

backbone

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12
Q

RNA can________ (nucleotides, and amino acids)

A

bind small molecules

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13
Q

RNA is ________

A

Coding

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14
Q

RNA has_______

A

catalytic activity

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15
Q

RNA can ________ and may have catalyzed its own synthesis.

A

self-replicate

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16
Q

The LUCA (Last Universal Common Ancestor) that lived on Early Earth that was Anoxic, and their metabolism was?

A

Exclusively chemolithotrophic and anaerobic

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17
Q

what were early carbon sources for microbes on early earth?

A
  • CO2

* Methane (CH4)

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18
Q

what were early electron donors for microbes on early earth?

A

• H2 - a powerful electron donor

- Ammonia (NH3) fixed by nitrogen fixation

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19
Q

what was one of the only (but most common) carbon source on early earth?

A

Atmospheric CO2

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20
Q

nitrogen was limited on early earth so cells needed a way to fix ____ to _____

A

N2 to NH4

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21
Q

What was likely the fuel for energy metabolism of early cells.

A

H2

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22
Q

Virtually all earliest branching Bacteria and Archaea used what, as an electron donor and are also classed as what?

A

H2, Autotrophs

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23
Q

what 4 question are needed, to know what kind of metabolisms a bacteria is doing?

A

Energy source?
Electron donor?
C source?
Electron acceptor?

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24
Q

Anoxygenic Photosynthesis is around for how long before cyanobacteria (oxygenic photosythisizers) show up?

A

about 1 billion years

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25
Q

what class of bacteria are Oxygenic Phototrophs? (3)

A

cyanobacteria
chloroplast
green non-sulfur bacteria

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26
Q

By 2.4 billion years ago, O2 rose to one part

per million. what is this even called?

A

Great Oxidation Event

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27
Q

Iron oxides precipitated and formed what?

A

Banded Iron Formations (BIF)

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28
Q

what New metabolisms during the great oxidation event evolved? (2 important)

A

sulfide oxidation,
nitrification
other aerobic chemolithotrophy

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29
Q

Entire Microbial ecosystem with many layers of organisms appear in fossil sediments. what bacteria appear near the top?

A

• Phototrophs (top near light)

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30
Q

Entire Microbial ecosystem with many layers of organisms appear in fossil sediments. what bacteria appear near the bottom?

A

chemolithotrophs (at bottom)

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31
Q

Entire Microbial ecosystem with many layers of organisms appear in fossil sediments. how are these bacteria organized within the formations?

A

organized by gradients of light and other resources (O2,NO32-, SO4, Fe2+,)

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32
Q

what is a Stromatolite?

A

Layers of Cyanobacteria and sediment, that pile up.

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33
Q

Fossil record indicates burst in rate of evolution with O2. Why did this burst occure? (3)

A

• aerobic metabolism yields more energy
• larger population sizes
• ozone layer (created following oxygenation)
protects DNA from UV radiation)

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34
Q

what is Systematics?

A

the study of diversity of organisms

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35
Q

what is taxonomy?

A

the naming and classifying organisms according to a set of rules.

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36
Q

what does Horizontal gene transfer allow?

A

Allows groups of bacteria to gain new functions from stolen genes of unrelated bacteria.

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37
Q

why are Eukarya considered genetic chimeras?

A

they contain genetic information found in both bacteria and archea.

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38
Q

what does LECA stand for?

A

LECA = Last Eukaryotic Common Ancestor

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39
Q

mitochondria and chloroplasts have there own ___

A

Circular DNA

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40
Q

Mitochondria and chloroplasts have ribosomes that resemble what?

A

Bacteria

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41
Q

mitochondria and chloroplasts have 16S rRNA sequences with similarities to what?

A

Bacteria

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42
Q

What machinery in eukaryotes is similar to archaea?

A

transcription and translational machinery

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43
Q

Haploid genomes mean?

A

there are only 1 allele for each gene

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44
Q

Origins of genetic diversity may be cause by what?

A

mutations

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45
Q

most genetic mutation are what kind?

A

neutral or deleterious

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46
Q

Rarely mutation are what kind?

A

Advantageous

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47
Q

what is it called when segments of DNA are broke and rejoined to create new combinations?

A

Recombination

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48
Q

what is ability of an organism to produce offspring and pass on genetic information?

A

Fitness

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49
Q

what is it called when the results of selection, select for the growth and reproduction of those individuals
over others?

A

Adaptive mutations

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50
Q

what is it called when a random process causes gene frequencies change over time in populations?

A

Genetic drift

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51
Q

if other species of bacteria produce needed metabolites of another species, what could happen?

A

Bacteria may lose function to produce a needed metabolite and evolve a mutual dependence.

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52
Q

what is form and function as it relates to

physiology and ecology

A

Functional diversity

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53
Q

what diversity is Based on 16S ribosomal RNA, or whole genome comparison

A

Phylogenetic diversity

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54
Q

what is the fundamental unit of biological diversity

A

a Species

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55
Q

Microbial Systematics combines what types of data? (3)

A
  1. Phenotypic
  2. Genotypic
  3. Sequence based phylogenetic data
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56
Q

what is The concept of a species as an irreducible group whose members are descended from a common ancestor and who all possess a combination of certain defining, or derived, trait?

A

Phylogenetic Species Concept

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57
Q

how does Niche occupation: “ecotype” work?

A

2 species occupy 2 different niches( Ectotype I and II) one of the species adapts to fill both niches and survives creating a third species and kills off the other 2 (ectotype III).

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58
Q

Why is Taxonomy so challenging in bacteria?

A

lateral gene transfer and homologous recombination

together can produce organisms effectively belonging to several species at once

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59
Q

when defining a species in bacteria a multiple combined method is used called what?

A

polyphasic approach

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60
Q

what polyphasic approaches are used in describing a bacterial species?

A
  • Phenotypic tests

- Genotypic tests

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61
Q

Of the phenotypic test conducted to speciate bacteria what methods are used?

A
  • Morphological traits and test

- Physiological tests

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62
Q

Of the genotypic test conducted to speciate bacteria what methods are used?

A
  • 16S rRNA gene sequencing

- Whole genome sequencing

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63
Q

“Type Strains” are what?

A

Live strain that serves as the center of

species and representative of that species

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64
Q

most of bacteria species are described with only one or two strains, the type strain of a species is what?

A

often the strain which was first discovered.

“type strain is not always Is not always the most typical representative of a species”

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65
Q

defined as any microorganism acquired from a recognized culture collection. It is the standard that allows it to be compared to other strains.

A

Reference bacterial strains

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66
Q

how is G+C content determined in samples?

A

by extracting DNA, and either melting it and looking at it

repairing with Spectrophotometry or HPLC.

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67
Q

DNA-DNA hybridization requires what?

A

2 extracted DNA samples

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68
Q

> 70-100 % hybridization = ???

A

same species

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69
Q

70-25% hybridization = ???

A

same genus

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70
Q

<25% hybridization = ???

A

different genera

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71
Q

SSU rRNA genes from other strains of the same species have _____ percent
sequence similarity

A

> 98.6

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72
Q

SSU rRNA genes from other strains from a different species have _____ percent
sequence similarity

A

< 97.0 percent similarity

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73
Q

Multilocus sequence analysis is what?

A

several “housekeeping genes” from several

related organism are sequenced and used to distinguish between them

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74
Q

Multilocus sequence analysis uses how many genes?

A

Usually use at least 4but up to 1000+ genes

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75
Q

Average nucleotide identity (A N I) is what?

A

the most used metric for estimating overall relatedness by aligning ~1000 b p fragments and calculating average nucleotide identity

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76
Q

what is a Candidatus designation?

A

Special Cases for species that cannot be cultured, or isolated from a mixed culture,

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77
Q

Proteobacteria belong to what hiarchy?

A

Phylum

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78
Q

Gammaproteobacteria belong to what hiarchy?

A

Class

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79
Q

Enterobacteri(ales)

A

Order

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80
Q

Enterobacteri(acea)

A

Family

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81
Q

what is special about Candidatus?

A

there are:

  • no pure cultures, or isolates
  • no type strains
  • only SEQUENCE
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82
Q

what Class does “Candidatus Pelagibacter ubique” belong to?

A

Alphaproteobacteria

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83
Q

probably the most abundant species on earth is?

A

Candidatus Pelagibacter ubique

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84
Q

Proteobacteria are divided into 6 classes, what are they?

A
  • Alphaproteobacteria
  • Betaproteobacteria
  • Gammaproteobacteria:
  • Deltaproteobacteria
  • Epsilonproteobacteria
  • Zetaproteobacteria
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85
Q

the ability to use Ferrous iron as a chemolithotrophy is common to what classes of proteobacteria?

A

Beta-, Zeta- and Epsilon-

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86
Q

all Proteobacteria are what when gram stained?

A

Negative

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87
Q

horizontal gene flow played what role in Proteobacteria?

A

important in shaping metabolic diversity

- ‘Wide range of metabolism”

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88
Q

Proteobacteria all have (2)?

A
  • extensive functional diversity

- Oligotrophic (grow at low concentrations)

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89
Q

Proteobacteria have Six major orders. 2 are important. what are they?

A

Rhizobiales, Rickettsiales

90
Q

Alphaproteobacteria Rhizobiales make what that does what and have a symbiotic relationship with plants.

A

makes rhizobia symbiosis (genera that cause plants to form a N2 fixing nodule)

91
Q

Alphaproteobacteria Rickettsiales are what?

A

obligate intracellular parasites or mutualists of animals

92
Q

Alphaproteobacteria Rickettsiales are unable to do what?

A

Unable to synthesize some metabolites and obtain them from host

93
Q

Betaproteobacteria are the Third-largest class of Proteobacteria and have 6 major orders. what are 4 important ones?

A
  • Burkholderiales
  • Methylophilales
  • Neisseriales
  • Nitrosomonadales
94
Q

Burkholderia cepacia has adaptations for life where?

A

the lungs

95
Q

Neisseria is commonly isolated from where?

A

animals

96
Q

Gammaproteobacteria Largest and most diverse class of Proteobacteria. they contain many what?

A

Many well-known human pathogens

97
Q

Class: Gammaproteobacteria

Enterobacteriales “Enteric Bacteria” are oxidase what, and catalase what?

A

oxidase negative and catalase positive

98
Q

Class: Gammaproteobacteria

Enterobacteriales “Enteric Bacteria” have what nutrition?

A

simple nutritional requirements

99
Q

what 2 Fermentation Patterns in Enteric Bacteria are there?

A

Mixed-acid fermentation and 2,3-butanediol fermentation

100
Q

P: Proteobacteria, Class: Gammaproteobacteria

Pseudomonadales are described how?

A

gram-negative, polarly flagellated, aerobic rod that uses diverse carbon sources

101
Q

P: Proteobacteria, Class: Gammaproteobacteria

Pseudomonadales use what respiration and use what metabolism?

A

Aerobic respiratory chemoorganotrophs

102
Q

P: Proteobacteria, Class: Gammaproteobacteria

Vibrionales are described how?

A

Facultative aerobic rods, that are curved (vibroid) and have Fermentative metabolism and are all oxidase
positive unlike Enteric bacteria.

103
Q

P: Proteobacteria, Class: Deltaproteobacteria contain what kind on elemental reducing bacteria?

A

Sulfate and sulfur reducing bacteria

104
Q

P: Proteobacteria, Class: Epsilonproteobacteria

Campylobacter, Helicobacter are found where?

A

Found in marine and terrestrial habitats, and metabolic capabilities suggest they play important ecological roles.

105
Q

P: Proteobacteria, Class: Epsilonproteobacteria

Helicobacter pylori cause what?

A

Helicobacter pylori causes chronic and acute gastritis and peptic ulcers

106
Q

P: Proteobacteria, Class: Zetaproteobacteria have a skill to change what?

A

Zetaproteobacteria play a major role in the engineering of their own environment

107
Q

P: Proteobacteria, Class: Zetaproteobacteria

Mariprofundus ferroxydans form what on ships?

A

(the only known species) 2010, produces stalks of solid iron oxyhydroxides that form into iron mats

108
Q

Phylum: Firmicutes, Tenericutes, Actinobacteria have 4 characteristics that define them, what are they?

A
  • Gram Positive bacteria
  • Contain ½ of all characterized species of Bacteria
  • Genomic DNA % Guanine:Cytosine separates them
  • Low GC Gram Positive Bacteria (Firmicutes)
109
Q

Phylum: Firmicutes

Bacillales and Clostridiales do not form what?

A

Non-spore forming (no endospores)

110
Q

Phylum: Firmicutes

Bacillus and Paenibacillus and Clostridium form what?

A

spore forming (endospores)

111
Q

Phylum: Actinobacteria

Streptomyces, Actinomyces, Nocardia produce what important compounds?

A

produce many antibiotics and antifungal compounds

112
Q

Phylum: Bacteroidetes

Bacteroidales cannot survive with oxygen present. what does this make them?

A

Obligately anaerobic fermentative

113
Q

Phylum: Bacteroidetes

Flavobacteriales are what?

A

Aerobic and facilitative anaerobic chemoorganotrophs.

114
Q

Phylum: Chlamydia

Chlamydia are what?

A

Obligate intracellular parasites

of eukaryotes

115
Q

Phylum: Hyperthermophilic Bacteria

Thermotoga are described as what?

A

rod-shaped hyperthermophiles that form sheath like envelopes (toga)

116
Q

Phylum: Hyperthermophilic Bacteria

Thermotoga 20% of its genetics came from where?

A

20% of genes likely originated from Archaea by horizontal gene transfer.

117
Q

Phylum: Hyperthermophilic Bacteria

Thermodesulfobacterium how are these bacteria similar to archaea

A

produces ether-linked lipids (like Archaea) but with unique C17 hydrocarbons and fatty acids

118
Q

archaea are not know to be ___?

A

pathogens

119
Q

Phylum Euryarchaeota inclues what strange archaea?

A

Includes extreme halophiles

120
Q

to balance high salt concentrations outside cell archaea do what?

A

hyperaccumulate compatible solutes in cytoplasm

121
Q

The light-mediated proton pump ______ helps extreme halophiles generate a proton motive force when oxygen is low

A

bacteriorhodopsin

122
Q

bacteriorhodopsin does what for archaea?

A

Pump out H+ that can be used to drive ATP

synthesis

123
Q

Archaea lack peptidoglycan isted they contain ____ that are linked by what kind of cross links?

A

Pseudopeptidoglyan

Connected by ß-1,3-linkages instead of ß-1,4

124
Q

Sugar+ protein cell walls are called what?

A

glycoprotein

125
Q

Extremely halophilic Archaea have what type of cell walls?

A

glycoprotein cell walls

126
Q

Special chemistry of some Achaea cell walls requires_____ for cell wall stability

A

high Na+ levels

127
Q

____inside cell must exceed Na+ level outside to maintain positive water balance

A

K+ level

128
Q

Archaea is the only domain that include _____

A

methanogens

129
Q

Where can you find Methanogens?

A
  • Anoxic sediments
  • Animal digestive tracts
  • Geothermal sources of H2 + CO2
  • Artificial biodegradation facilities:
130
Q

Methanogenesis results from CO2 + H2 explain the reaction.

A

4H2 + HCO3- + H+ —> CH4 + H2O

131
Q

how much energy does Methanogenesis produce?

A

ΔG°’ = -136 kJ (~1 ATP)

132
Q

sterilization technique for medical equipment is

121 °C for 20 minutes how much is it for Achaea?

A

10 hours at 121°C (250°F), 15 psi

133
Q

adaptations of hyperthermophiles (4)

A

Lipid monolayer
Heat shock proteins
Reverse DNA gyrase
DNA binding proteins

134
Q

Euryarchaeota contain what groups of Archaea?

A

Methanogens

Extreme halophiles

135
Q

Crenarchaeota contain what group of Archaea?

A

Hyperthermophiles

136
Q

Thaumarchaeota contain what group of Archaea?

A

Ammonia oxidizers

137
Q

Why is it hard to kill viruses?

A

t’s hard to “kill” something that’s not
really alive, so antibiotics that kill bacteria,
fungi, etc, do NOT harm viruses

138
Q

All viruses consist of at least 2 components what are they?

A

Genetic Material-usually a single DNA or RNA molecule, can be single or double stranded, linear or circular and contains the viral genes

Capsid -a hollow protein capsule which houses the genetic material

139
Q

Some viruses may also contain what along with a capsid and genetic material?

A

Envelope-membrane from host cell with viral proteins (spikes) that surrounds the capsid

140
Q

The Virion Capsid contains how many proteins and is arranged how?

A

consist of >1 type of protein, arranged in a precise and highly repetitive pattern

141
Q

Virion Capsid Can be put together through self-assembly (spontaneous) but some require what to help them fold?

A

require host cell folding assistance, such as protein folding proteins

142
Q

The Viral Envelope come from where?

A

membrane comes from host cell

143
Q

Helical Viruses have what unique characteristics? (2)

A
  • “helical” arrangement

- They also lack an envelope

144
Q

Enveloped Viruses have what unique characteristics? (2)

A

-capsid is enclosed within an envelope
-Envelope proteins attach to and infect animal
host cell.

145
Q

Complex Viruses such as the T4 bacteriophage have tail fibers that do what?

A

Tail aids in attachment and penetration of host

146
Q

how many kilobases is the smallest bacterial genome?

A

Smallest bacteria genome is 139 kbases, (with 110 genes)

147
Q

Viral Genetic Material can be made of what?

A

Made of either DNA or RNA

148
Q

Viral Genetic Material (DNA or RNA) come in what 2 forms?

A

Double-stranded (ds) or single-stranded (ss)

149
Q

Virus Classification: The Baltimore Scheme is biased on what?

A

Based on the relationship of the genome to mRNA

150
Q

Virus Classification: The Baltimore Scheme RNA viruses what must catalyze replication?

A 
RNA replicase (catalyzes replication 
of RNA from RNA)
151
Q

DNA versus 2 important characteristics?

A
  • Accurate Replication

- Protected by cell

152
Q

RNA viruses 2 important characteristics?

A

-Error-prone replication
-dsRNA actively degraded by cell
• RNA must be protected during
replication and assembly

153
Q

what does Lysozyme do? (2)

A

• makes hole in cell wall to allow
nucleic acid entry
• also lyses bacterial cell to release
new virions

154
Q

what does Neuraminidases do? (2)

A

• destroy glycoproteins and glycolipids
• enables the virus to be released from
the host cell.

155
Q

what does RNA replicases (RNA-dependent RNA

polymerases) do?

A

enzyme that reproduces viral RNA is known as an RNA-dependent RNA polymerase

156
Q

what does Reverse transcriptase (RNA-dependent DNA polymerase) in retroviruses do?

A

• Synthesizes viral genome as DNA from an RNA template, then dissolves the RNA template.
• Produces a double-stranded DNA molecule, can be
integrated into the host genome, then gets transcribed
back to RNA

157
Q

Virulent (lytic) infection does what to host?

A

replicates itself then destroys host

158
Q

lysogenic infection does what to host?

A

host cell genetically altered because viral genome becomes part of host genome

159
Q

Temperate Phages can do what?

A

can oscillate between lytic and lysogeny

160
Q

DNA viruses that infect animals may use what kind of dna?

A

May be single stranded (ss) or double stranded (ds) DNA

161
Q

RNA viruses that infect animals may use what kind of rna?

A

single stranded (ss) ordouble stranded (ds) RNA

162
Q

The 4 major categories of coronavirus are known as alpha, beta, delta and gamma. which are infectious to humans?

A

Only alpha and beta coronaviruses are known to infect humans

163
Q

what are the 5 Phases of viral replication?

A
  1. attachment, (adsorption) of the virion
  2. penetration, (entry, injection) of the virion nucleicacid
  3. synthesis, of virus nucleic acid and protein by host cell metabolism as redirected by virus
  4. assembly, of capsids and packaging of viral genomes into new virions
  5. release, of mature virions from host cell
164
Q

what does a bacterial phage require on the surface of a host to infect it?

A

requires complementary receptors on the surface of a susceptible host for its infecting virus

165
Q

what is the process of Synthesis of Lytic replication of bacteriophage T4

A
  • Bacterial DNA is degraded by enzyme brought by virus

- dsDNA viral genome is replicated and transcribed by the host

166
Q

how are viruses quantified?

A

titer: number of infectious units per volume of fluid

167
Q

what is viral Lysogeny?

A

genome is either integrated into bacterial chromosome (lambda) or exists as a plasmid within host

168
Q

what is a prophage?

A

the viral DNA in a host chromosome

169
Q

Viral Insertion into host genome requires what

enzyme

A

integrase/recombinase

170
Q

what protein keeps it a virus dormant when integrated into the dna of a host?

A

Virally-encoded phage repressor

171
Q

what stimulates the lytic cycle in a prophage?

A

induction of Environmental stressors or damage to host DNA

172
Q

how many viruses are estimated to be on earth?

A

1x10^31 viruses on Earth

173
Q

all Achaea viruses have what qualities? (3)

A
  • They are all DNA viruses (so far)
  • Mostly dsDNA virus
  • A few ssDNA virus
174
Q

what are RNA viruses that replicate through a DNA

intermediate called?

A

Retroviruses

175
Q

Integration of retroviral DNA into host genome is referred to as what?

A

integrase

176
Q

Prions are what?

A

Infectious proteins

• No nucleic acid component

177
Q

prions infectious cycle cause host proteins to do what?

A

PrPSc (misfolded) cause misfolding in proteins

178
Q

Non-pathogenic prions found in fungi help with what processes? (2)

A

• Adapt the cells to survive changes in environment
• Confer traits like altered nutrient use, antibiotic
resistance, and biofilm formation

179
Q

• Non-pathogenic prions in humans help with what?

A

• prions are Part of immune system

180
Q

Bacteria and Archaeal chromosomes are how long and what shape?

A

long and usually circular

181
Q

Eukaryotic chromosomes are how long and what shape?

A

long and linear

182
Q

Plasmids are typically what kind of dna?

A

dsDNA

183
Q

Supercoiled domains prevent what from happening?

A

prevent complete unfolding if a nick is introduced

184
Q

Densely packed DNA forms the what?

A

nucleoid

185
Q

Negative supercoiling mean the dna is what?

A

double helix is underwound (opp of helical twist)

186
Q

Positive supercoiling mean the dna is what?

A

double helix is overwound (same direction as helical twist)

187
Q

what supercoiling is predominantly found in nature?

A

Negative

188
Q

Hyperthermophilic Archaea use what supercoiling?

A

use positive supercoiling which are more stable at high temperatures

189
Q

an important enzyme in prokaryotes, introducing negative supercoils to the DNA

A

DNA gyrase

190
Q

used by hyperthermophilic Archaea, b/c they are

positively supercoiled

A

reverse DNA gyrase

191
Q

Ciprofloxacin inhibits what in bacteria?

A

Inhibits DNA gyrase

192
Q

Eukaryotes use what dna polymerase?

A

DNA Polymerase δ (delta)

193
Q

Prokaryotes use what dna polymerase?

A

DNA Polymerase III holoenzyme

194
Q

The Replisome in prokaryotes consist of what main enzymes? 3

A
  • DNA gyrase removes supercoils
  • DNA helicase unwinds DNA helix
  • Tau holds the 2 DNA polymerases and helicase together
195
Q

acheae replication is different then prokaryote replication in what manner?

A

archeae replication can have 1, 2, 3, 4 origins of replication! prokaryotes just 1.

196
Q

Prokaryotic genes are grouped in segments called what?

A

operons

197
Q

Prokaryotes are polycistronic, meaning what?

A

more than one gene transcribed in a mRNA segment

198
Q

DNA segments transcribed into 1 RNA molecule

bounded by initiation and termination sites in bacteria

A

bacterial Transcriptional units

199
Q

Operons are transcribed into a single mRNA called what?

A

polycistronic mRNA

200
Q

polycistronic mRNA containing ____ that encode amino acids

A

multiple open reading frames

201
Q

Transcription in all Domains require what?

A

promoters (DNA sequences indicating where to initiate

transcription)

202
Q

Eukarya contain different RNA polymerases for different types of RNA what are 2 of them?

A
  • RNA polymerase II – mRNA

* Transcription factors to initiate the process

203
Q

Bacteria and Archaea have what polymerase and rely on what to identify promoter regions?

A

• Single RNA polymerase

-sigma factors

204
Q

Archaeal polymerase resembles eukaryotic what?

A

RNA polymerase II

205
Q

Bacterial transcription RNA polymerase does what, and has no need for what?

A

unwinds the DNA as it goes
• No need for a helicase
• No need for a primer (not replication)

206
Q

Sigma factors are critical to Bacterial transcription and do what?

A

recognizes initiation sites on DNA

called promoters

207
Q

Pribnow box is what?

A

the (–10 region) and TTGACA (–35 region).

208
Q

Rho-independent termination involves what?

A

inverted repeat structure leads to the RNA polymerase terminating

209
Q

Rho-dependent termination involves what?

A

recognizes specific RNA sequence in the mRNA, attaches and travels up the transcript to the RNA polymerase, where it causes the RNA polymerase to fall apart,

210
Q

Transcription in Archaea is similar to what other domain?

A

Transcription machinery is like Eukarya

211
Q

Archaea Regulation of transcription is like what other domain?

A

Bacteria

212
Q

exons are what?

A

exons: coding sequences

213
Q

introns are what?

A

introns: intervening noncoding

sequences that are excised out.

214
Q

introns are rare in Archaea but can be found where?

A

found within tRNA and rRNA genes of Archaea

215
Q

Rifampicin inhibits what in bacteria?

A

Inhibits bacterial RNA polymerase

216
Q

AUG encodes methionine in eukaryote. what does it code for in bacteria?

A

AUG encodes formylmethionine in bacteria

217
Q

release factors (RF) recognize what and do what?

A

stop codon and cleave polypeptide from tRNA

218
Q

Streptomycin interferes with what in bacteria?

A

with the binding of formyl-methionyl-tRNA to the 30S subunit

219
Q

Chloramphenicol prevents what in bacteria?

A

prevents peptide bond formation

220
Q

Cycloheximide affects eukaryotes and binds to what and does what?

A

Binds to ribosome and Prevents tRNA and mRNA from moving

Microbiology (4 decks)

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