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Microbio > Unit 4: Chapter 28 > Flashcards

Unit 4: Chapter 28 Flashcards

1
Q

_________ increasing mating season for mosquitoes that carry disease causing microbes

A

Warmer temperatures

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2
Q

Increased temperature is caused from

A

climate change

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3
Q

Biogeochemical cycling

A

Sum of microbial, physical, and chemical processes that drive the flow of elements with influx of nutrients from one pool to another

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4
Q

Flux

A

nutrients move between pools and are chemically modified

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5
Q

Abiotic processes

A

Nonliving
Ex. Erosion

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6
Q

Biotic processes

A

Living and refers to nutrient cycling

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7
Q

Nutrients refer to

A

chemicals (inorganic and organic)

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8
Q

Nutrient cycling is performed by

A

bacteria, archaea, and eukaryotic microbes

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9
Q

Microbes on Earth’s surface contribute to

A

rapid nutrient cycling

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10
Q

Microbes on very slow growing deep surface contribute to

A

elemental cycling over geological periods

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11
Q

What if all prokaryotes suddenly vanished from Earth suddenly?

A

No one can live since nutrient cycling and biochemical cycling will be shut down

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12
Q

Redox potential

A

measure of the tendency of molecules in a system to accept or donate electrons

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13
Q

Redox potential is determined by the electrical potential difference betweeen ___ and ________

A

environment; standard hydrogen electrode

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14
Q

Redox potential is expressed in

A

volts or millivolts

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15
Q

Low redox potential

A

Readily donate electrons

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16
Q

High redox potential

A

Readily accept electrons

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17
Q

Redox state of environment plays a critical role in

A

determining the types of microbes present

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18
Q

Redox stae of environmental determines the types of microbes by:

A
  1. which oxidized compounds are available as terminal electron acceptors
  2. what reduced molecules are present for use as electron donors
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19
Q

What influence the availability of terminal electron acceptor?

A

Redox potential, pH, and oxygen concentration

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20
Q

______ declines with depth in water and soil

A

Oxygen concentration

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21
Q

ΔG°’ negative indicates

A

exergonic, more free energy released

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22
Q

ΔG°’ positive indicates

A

endergonic, less free energy released

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23
Q

More positive value of ΔG°’ indicates

A

less energy released and more in depth

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24
Q

What processes provide greatest amount of energy?

A

Aerboic respiration

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25
Q

Which processes provide least amount of energy?

A

Methanogenesis by Archaea

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26
Q

Reduced form

A

Gaining electrons and H+, lose O2

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27
Q

Oxidized form

A

Losing electron and H+, gain O2

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28
Q

What elements contain intermediate oxidation state forms?

A

Carbon, nitrogen, sulfur

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29
Q

What elements do not contain intermediate oxidation state forms?

A

Iron, phosphate, maganase

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30
Q

Fate of organic materials:

A

Minneralization and Immobilization

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31
Q

Minneralization

A

decomposition of organic matter to simpler inorganic compounds (O2, NH3, H2,..)
may or may not be recycled

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32
Q

Immobilization

A

nutrients converted into biomass become temporarily unavailable for nutrient cycling

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33
Q

____ are important in mineralizing immobilized organic compounds

A

Saprophytes

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34
Q

What elemnt is most abundant?

A

Carbon

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35
Q

____ is continously transformed from form to another

A

Carbon

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36
Q
A
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37
Q

CO2 is reduced to

A

methan (CH4)

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38
Q

Methanogenesis

A

No O2 available (anaerobic)
CO2 reduced to CH4 by methane by archaea

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39
Q

Reverse methanogenesis

A

Archaea and reducing bacteria work togerther to oxidize methan using sullfate as terminal electron acceptor

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40
Q

Methanotrophy and methylotrophy

A

O2 available (anaerboic and aerboic)
CH4 oxidized to CO2

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41
Q

CO2 fixation

A

O2 available (anaerboic and aerboic)
CO2 reduced to organic matter
Phototrophy and Chemotrophy

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42
Q

Oxidative and redox neutral

A

Aerboic/ Anaerboic respiration and fermentation
Organic matter oxidized to CO2

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43
Q

All fixed carbon enters common pool of organic matter that can be oxidized back to CO2 through

A

aerobic/ anaerobic respiration and fermentation

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44
Q

Inorganic carnon (CO2) and organic carbon can be reduced _____ to methane

A

anaerboically

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45
Q

Source of carbon

A

heterotrophic microbes and burning of fossil fuels release carbon as CO2
fossil fuels and CO

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46
Q

Carbon sinks

A

plants, phytoplankton, and other autotrophic microbes that TAKE UP CO2 from atmosphere

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47
Q

Carbon reservoirs

A

STORE carbon for geological periods of time

48
Q

Methane oxidized ___ by bacteria or _____ by archaea

A

Aerboically, anaerboically

49
Q

_______ found in rice paddies, ruminant animals, coal mines, sewage treatment plants, landfills, and marshes

A

Methane sediments

50
Q

Degradation of organic matter influenced by several factors including:

A
  1. oxidation reduction potential
  2. availability of competing nutrients
  3. abiotic conditions (pH, temperaturem O2, osmotic conditions)
  4. microbial community present
51
Q

Microorgnaisms secrete hydrolytic enzymmes that degrade ___

A

Ligin

52
Q

Microorgnaisms secrete hydrolytic enzymmes that degrade ligin include

A

Fungi (eukaryotic) and streptomyces (prokaryotic bacteria)

53
Q

Microorgnaisms that degrade ligin only contain

A

carbon, hydrogen, oxygen

54
Q

Microorgnaisms that degrade ligin must

A

acquire remaining nutrients

55
Q

Limiting nutrient

A

nutrient that is insufficient for maximal growth

56
Q

Nitrogen exists in redox states from

A

-3 to +5

57
Q

Nitrogen species serve as electron acceptor in ____ or as electron donor in ______

A

anaerboic respiration; chemolithotrophy

58
Q

Nitrogen fixation

A

N2 gas reduced to NH3

59
Q

Nitrogen fixation is carried out by

A

some bacteria and archaea
oxic and anoxic conditions

60
Q

What bacteria involved in nitrogen fixation under oxic conditions?

A

Clostridium

61
Q

Product of nitrogen fixation is

A

Ammonia (NH3)

62
Q

Bacteria which help with nitrogen fixation

A

Azotobacter
Clostridium
Rhizobiales
Cyanobacteira

63
Q

Assimilation

A

NH3 converted to organic N
Taken up by plants and animals

64
Q

Mineralization in nitrogen cycle

A

Organic N reduced NH4+

65
Q

Commanox

A

NH4+ oxidized to NO3- (nitrate) in 1 step by mitrospira

66
Q

Mitrospira

A

bacteria that helps commanox

67
Q

Nitrification

A

NH4+ oxidized to NO3- in 2 steps

NH4+ –> NO2-
NO2- –NO3-

68
Q

In Nitrification __ donates electron

A

Ammonium (NH4+)

69
Q

NH4+ in nitrification is e- donor or e- acceptor

A

e- donor
reduced form

70
Q

NO3- in nitrification is e- donor or e- acceptor

A

e- acceptor
oxidized form

71
Q

Assimiliary nitrate reduction

A

NO3- is reduced to NH4+ and taken up by organisms
Incorporated into microbial and plant cell biomass

72
Q

Dissimilary nitrate reduction

A

NO3- (nitrate) is used as terminal e- acceptor during anaerobic respiration and reduced to N2 (nitrogen gas)
NO3- –> N2
Nitrogen is removed from cytoplasm and returned to atmosphere

73
Q

Ammanox

A

NH4+ reduced to N2 with NO2 as terminal e- acceptor
Shortcut to produced N2 gas without going to nitrate
Anaerboic!

74
Q

Denitrification

A

loss of nitrate by process of anaerboic respiration of soil bacteria
occurs in flooded/ waterlogged soils
Converts nitrate into gaseous nitrogen that enters atmosphere and represents considerable economic loss

75
Q

Why is denitrification a problem for farmers?

A

Loss of nitrogen and comverts into gaseous nitrogen to atmospheric
ECONOMIC LOSS

76
Q

Phosphorus in nature exist as

A

Phosphate ion PO43-

77
Q

Phosphorus is required for

A

ATP, nucleic acids, lipids, polsaccharides

78
Q

Source of phosphorus

A

Weathering of phosphate containing rocks

79
Q

Eutrophication

A

Phosphorus and nitrogen are suddenly too abudant (too many nutrients) and promote growth of algae bloom in water

80
Q

_____ is not abudant and is limiting nutrient which limit growth of organism

A

Phosphorus

81
Q

Cause of eutrophication

A

Phosphorus in run off water

82
Q

Depending on oxidation state of sulfur species it can serve as

A

e- aceptor, e- donor, or both

83
Q

____,_____, and ______ are abudant in detergent and fertilizer

A

phosphate, phosphorus, and nitrogen

84
Q

Some organisms can use ___ as carbon energy source

A

sulfur

85
Q

Dissimalatory sulfate reduction

A

Use of sulfate as terminal e- acceptor where organsism die and degraded by saprophytes to return sulfate back into environment

86
Q

Assimilary sulfate reduction

A

Sulfate (fully oxidized) is reduced by plants and microbes for use in amino acid and protein synthesis

87
Q

In dissimalatory sulfate reduction, resulting ____ is not taken up for use in _____

A

Ferrous iron (Fe2+); cellular biosynthesis

88
Q

assimiliate in reference to nitrogen and sulfur use means:

A

take in so nitrate and sulfate used for growth

89
Q

______ forms can not be incorportaed directly into organic molcules so it must first be ____ through process _________

A

oxidized, reduced, assimilatory reduction

90
Q

Dissimilatory reduction in reference to nitrogen and sulfur use means:

A

using nitrate or sulfate as e- sink
resulting reduced compound is NOT taken up by microorganism

91
Q

Sulfur cycle resembles ___ cycle

A

phosphorus

92
Q

Why does the sulfur resemble the phosphorus cycle?

A

Sulfur is mostly in solid form
Orginates from natural sedimentary deposits in rocks, oceans, lakes, and swamps rather than atmosphere like nitrogen

93
Q

_____ is essential elemt in very small quantities

A

Free iron

94
Q

___ is transfered into the cell in iron cycle

A

Fe3+

95
Q

Iron often exists in ____ state for uptake

A

wrong oxidation state

96
Q

___ bind Fe3+ and faciliate its transport into the cell and is reduced to Fe2+

A

siderophores

97
Q

Dissimilatory reduction in iron cycle

A

Fe3+ serves as terminal e- acceptor during anaerboic respiration

98
Q

Mganese cycle, transformed reduced ___ to oxidized _____

A

Mn2+, MnO2

99
Q

Diverse bacteria use ___ as e- donor with oxygen or ___ as terminal e- acceptor

A

Mn2+, nitrate

100
Q

____ molecules link carbon cycle to either nitrogen, sulfur or iron cycle

A

chemolithotrophic

101
Q

Biogeochemical cycling is ____ and ____ processes which keep biosphere __________

A

dynamic, interconnected, self sustaining

102
Q

Global climate change indicates biochemical cycling is

A

out of balance

103
Q

___ is critical in maintaining dynamic equilibrium that defines our biosphere

A

microbial activity

104
Q

Global climate change

A

term that reflects changes in patterns of wind, precipiation, and ocean and atmospheric temperatures that Earth is now experiencing

105
Q

What are the 3 green house gasses?

A

Carbon Dioxide (CO2), Methan (CH4), and nitrous oxide (H20)

106
Q

Greenhouse gases

A

Trap heat reflected from Earth’s surface rather than allowing it to radiate into space

107
Q

When do green gasses accumulate?

A

If rate of gasses enter atmopshere exceeds by which natural carbon and nitrogen cycle can remove them

108
Q

Accumulation of gasses has resulted in

A

global warming

109
Q

What gas contributes the most to global warming?

A

Methane (CH4)

110
Q

Methan contributes ___ times global warming potential than CO2

A

30 times

111
Q

The consequences of disrupting Nitrogen and Carbon cycle:

A

Global climate change

112
Q

Why is methane the most causing greenhouse gas?

A

Single CH4 has same thermal retention capacity as 30 CO2 molecules

113
Q

Methan has increased ___ times to present level in last 10 years

A

2.5

114
Q

Global climate change is measured over;

A

decades

115
Q

Parameters of global climate change is measured by:

A
  1. surface temperature on land, sea, atmosphere
  2. rates of precipitation
  3. frequency of extreme weather

Microbio (18 decks)

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