Block E 1 Flashcards

extremophiles - the archaea (45 cards)

1
Q

difference between archaea and bacteria

A

-more chem and structurally diverse
-semi rigid lattice of pseudomurein, sugars, proteins, or glycoproteins
-NO PEPTODOGLYCAN

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2
Q

4 ways in which archaea lipids are unique

A

-ether linked lipids (not ester)
-side chains are branced isoprenes (not fatty acids)
-different chiral form of glycerol (L)
-some possess lipid monolayers

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3
Q

archaeal flagella are superficially similar to bacterial flagella but what are archaeal flagella considered to be

A

non homologous
(convergent evolution)

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4
Q

how are bacterial flagella produced

A

by addition of flagellin subunits at the tip

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5
Q

how are archaeal flagella produced

A

by addition of flagellin subunits at the base

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6
Q

main difference of bacterial flagella compared to archaeal

A

bacterial are thicker and hollow allowing flagellin sub units to pass through

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7
Q

what are the 5 major groups that archaea are split into

A

-euryarchaeota
-crenarchaeota
-thaumarchaeota
-korarchaeota
-nanoarchaeota

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8
Q

what do these key genera belong to
halobacterium
haloferax
natronobacterium

A

euryarchaeota
(haloarchaea)

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9
Q

what do halophiles have a requirement for

A

high salt concs

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10
Q

where are haloarchaea found

A

artificial saline habitats (salted foods)

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11
Q

how do haloarchaea reproduce

A

binary fission

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12
Q

what do haloarchaea not form

A

resting stages or spores
(most are non motile)

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13
Q

what adaptation do haloarchaea possess that allow them to live in highly ionic concentrations

A

cell wall is composed of glycoprotein and stabilized by Na

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14
Q

how do halophiles maintain osmotic balance

A

accumulation/synthesis of compatible solutes

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15
Q

how do halobacterium maintain osmotic balance

A

pump large amount of K into the cell from the environment
(intracell K exceeds extracell Na= positive water balance)

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16
Q

pH of halophile proteins

A

highly acidic

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17
Q

what are some haloarchaea capable of

A

light driven synthesis of ATP

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18
Q

what do proteins of halophiles contain fewer of

A

hydrophobic amino acids and lysine residues

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19
Q

what group does this key genera belong to
methanobacterium
methanocaldoccus
methanosarcina

20
Q

what are methanogens

A

microbes that produce CH4

21
Q

4 examples of cell wall chemistry diversity that methanogens have

A

pseudomurein
methanochondroition
protein or glycoprotein
S-layers

22
Q

how many substrates do methanogens have

A

11
divided into 3 classes, and can be converted to CH4 by pure cultures of methanogens

23
Q

how can other compounds (eg glucose) be converted to glucose

A

cooperative reactions between methanogens and other anaerobic acteria

24
Q

what group does the following key genera belong to
thermoplasma
picrophilus
ferroplasma

A

thermoplasmatales

25
what can be said about the heat and pH adapatability of thermoplasmatales
thermophillic and/or extrememly acidophilioc
26
what do thermoplasma and ferroplasma lack
cell walls
27
how does thermoplasma obtain their energy
chemorganotrophs
28
thermoplasma are facultative aerobes via what
sulfur respiration
29
where is thermoplasma found
self heating coal piles
30
what has thermoplasma evolved to maintain +ve osmotic balance
unique cytoplasmic membrane structure lipoglycan consisting of tetraether lipid monolayer membrane with mannose and glucose does not contain sterols
31
how does ferroplasma obtain energy
chemolithotrophic
32
how does ferroplasma generate acid
oxidises Fe2 to Fe3
33
what pH do picrophilus grow at
pH 7 extreme acidophiles
34
what are picrophilus known for
being a model microbe for extreme acid tolerance
35
what groups does this key genera belong to thermococcus pyrococcus methanopyrus
thermococcales and methanopyrus
36
where are thermococcus and pyrococcus indigenous to
anoxic themal waters
37
how to crenarchaeota obtain energy
chemoorganotrophs or chemolithotrophs with diverse electron donors and acceptors
38
where are most cultured representatives of crenarchaetoa found
extreme hot or cold environments most are hyperthermophiles
39
where do sulfolobales grow
sulfur ruch acidic hot springs
40
where do acidianus live
acidic sulfur hot springs
41
what to lab exp with biomolecules suggest the upper limit for microbial life
140-150 degrees cel.
42
what adaptations have been made to allow lipid stability for life at high temps
possess dibiphytanyl tetraether type lipids form lipid monolayer membrane structure
43
what adaptations have been made to allow small subunit (SSU) rRNA stability
higher GC content
44
where is reverse DNA gyrase only found
in hyperthermophiles
45
on what branch are hyperthermophilic archaea and bacteria found on phylogenetic tree
deepest shortest branches