Block E 1 Flashcards
extremophiles - the archaea
difference between archaea and bacteria
-more chem and structurally diverse
-semi rigid lattice of pseudomurein, sugars, proteins, or glycoproteins
-NO PEPTODOGLYCAN
4 ways in which archaea lipids are unique
-ether linked lipids (not ester)
-side chains are branced isoprenes (not fatty acids)
-different chiral form of glycerol (L)
-some possess lipid monolayers
archaeal flagella are superficially similar to bacterial flagella but what are archaeal flagella considered to be
non homologous
(convergent evolution)
how are bacterial flagella produced
by addition of flagellin subunits at the tip
how are archaeal flagella produced
by addition of flagellin subunits at the base
main difference of bacterial flagella compared to archaeal
bacterial are thicker and hollow allowing flagellin sub units to pass through
what are the 5 major groups that archaea are split into
-euryarchaeota
-crenarchaeota
-thaumarchaeota
-korarchaeota
-nanoarchaeota
what do these key genera belong to
halobacterium
haloferax
natronobacterium
euryarchaeota
(haloarchaea)
what do halophiles have a requirement for
high salt concs
where are haloarchaea found
artificial saline habitats (salted foods)
how do haloarchaea reproduce
binary fission
what do haloarchaea not form
resting stages or spores
(most are non motile)
what adaptation do haloarchaea possess that allow them to live in highly ionic concentrations
cell wall is composed of glycoprotein and stabilized by Na
how do halophiles maintain osmotic balance
accumulation/synthesis of compatible solutes
how do halobacterium maintain osmotic balance
pump large amount of K into the cell from the environment
(intracell K exceeds extracell Na= positive water balance)
pH of halophile proteins
highly acidic
what are some haloarchaea capable of
light driven synthesis of ATP
what do proteins of halophiles contain fewer of
hydrophobic amino acids and lysine residues
what group does this key genera belong to
methanobacterium
methanocaldoccus
methanosarcina
methanogens
what are methanogens
microbes that produce CH4
4 examples of cell wall chemistry diversity that methanogens have
pseudomurein
methanochondroition
protein or glycoprotein
S-layers
how many substrates do methanogens have
11
divided into 3 classes, and can be converted to CH4 by pure cultures of methanogens
how can other compounds (eg glucose) be converted to glucose
cooperative reactions between methanogens and other anaerobic acteria
what group does the following key genera belong to
thermoplasma
picrophilus
ferroplasma
thermoplasmatales
what can be said about the heat and pH adapatability of thermoplasmatales
thermophillic and/or extrememly acidophilioc
what do thermoplasma and ferroplasma lack
cell walls
how does thermoplasma obtain their energy
chemorganotrophs
thermoplasma are facultative aerobes via what
sulfur respiration
where is thermoplasma found
self heating coal piles
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
how does ferroplasma obtain energy
chemolithotrophic
how does ferroplasma generate acid
oxidises Fe2 to Fe3
what pH do picrophilus grow at
pH 7
extreme acidophiles
what are picrophilus known for
being a model microbe for extreme acid tolerance
what groups does this key genera belong to
thermococcus
pyrococcus
methanopyrus
thermococcales and methanopyrus
where are thermococcus and pyrococcus indigenous to
anoxic themal waters
how to crenarchaeota obtain energy
chemoorganotrophs or chemolithotrophs with diverse electron donors and acceptors
where are most cultured representatives of crenarchaetoa found
extreme hot or cold environments
most are hyperthermophiles
where do sulfolobales grow
sulfur ruch acidic hot springs
where do acidianus live
acidic sulfur hot springs
what to lab exp with biomolecules suggest the upper limit for microbial life
140-150 degrees cel.
what adaptations have been made to allow lipid stability for life at high temps
possess dibiphytanyl tetraether type lipids
form lipid monolayer membrane structure
what adaptations have been made to allow small subunit (SSU) rRNA stability
higher GC content
where is reverse DNA gyrase only found
in hyperthermophiles
on what branch are hyperthermophilic archaea and bacteria found on phylogenetic tree
deepest shortest branches
