Biol 240: Archaea

Who were the first to discover Archaea?

Woese and Fox in the 1970s

What were the first archaea?

methanogens

How big are archaea?

0.5-5 micrometers

What are the names of the large archaea and the very small ones that are always around it?

Ignococcus hospitalis and nanoarchaeum equitans

Pleomorphic

irregular or variable shape

what are two examples of archaea shapes that are different from bacteria?

rectangles and squares

Why would an archaea like haloquadratim walybi be in a square shape?

allows for increased surface area to body ratio, meaning more pickup of nutrients. It also allows fro more access to sun light

what are different between archeal histones and eukaryal histones?

eukaryotes have octamers of histones while archaea have tetramers

what is included within the cell envelope of an archaea cell

thin cell wall with no outer membrane (has cytoplasmi membrane)

What is special about the archaea cytoplasmic membrane

it is a monolayer

isoprene unit

5 carbon chains

phytanyl chain

2 isoprene units

biphytanyl chain

2 phytanyl chains

what type of linkage links the fatty acid chains to the glycerol in archaea?

ether linkages

what specific molecule is used in the cytoplasmic membrane?

glycerol-1-phosphate

what structue can be present within faty acids to affect the stability of the membrane?

rings in the lipids

rare archaea that has an outer membrane

Ignicoccus

what material makes up the archaeal cell wall?

pseudomurein

what is pseudomurein made out of?

NAG-NAT-NAG-NAT with peptide bridges connected to NAT

would lysozyme work on the NAG-NAT bond?

no

cannulae

hollow glycoprotein tubes that link cells together to form a complex network

Archaeal version of a flagella

archaellum

What is different about the Archaellum when comparing it to a flagellum?

Archaella are solid tubes that are powered by ATP

4 major phyla of archaea:

Crenarcheota, Euryarchaota, Thaumarchaota and Nanoarcheota

Crenarchaeota

(hyper)thermophiles, acidophiles, and barophiles that like to live at extreme, acidic temperatures, and at the bottom of the ocean near thermal vents.

Thermophiles

temperatures from 50-80 degrees

Hyperthermophiles

Archaea growing about 80 degrees celcius and some above 100 degrees celcius

Acidophiles

grow in acidic environments

Barophiles

organisms that live under extreme pressure

5 ways crenarcheota survive in extreme temperatures:

tetraether lipids/ lipid monolayer, modified proteins, strong chaperone proteins (help keep proteins together), thermostable DNA-binding proteins, reverse DNA gyrase enzyme to help supercoil DNA

4 ways crenarcheota modify their proteins:

more alpha-helices, more salt bridges/side chain interactions, more arginine/tyrosine, less Cystein/Serine

What environment do halophilic Euryarcheota usually exist in?

high salt concentration environments

halophile

"salt-loving" archaea that live in environments that have very high salt concentrations

what is the minimum salt concentration a halophile must exist in?

1.5 M

How do halophiles deal with the osmotic shock and loss of water?

They contain a high inner concentration of Potassium Ions

How do halobacteria prevent the large concentration of K+ from denaturing proteins and DNA?

proteins are usually more acidic, and DNA usually has more Guanine and Cytosine because of the more hydrogen bonding

Phototrophic

do not have chlorophyl or an electron transport chain to produce energy, so they utilize bacteriorhodopsin to create a proton-motive force (gives off reddish hue)

What is the only phyla methanogens belong to?

Euryarcheota

Order the three types of methanogens from most abundant to least abundant:

Hydrogenoclastic, Acetoclastic, Methylotrophic

Hydrogenoclastic

blows up hydrogen

Acetoclastic

blows up acetate

Methylotrophic

creates methane

What molecule do methanogens reduce and what do they reduce it with?

methanogens reduce CO2 with H2, creating energy

Are methanogens aerobic or anaerobic?

They are strictly anaerobic

Where can methanogens usually be found?

in animal intestines (rumen, cecum, large intestine), Anoxic sediments (swamp, lake, moist landfill, etc.), hydrothermal vents, and artificial biodegridational facilities

brief description of the Volta experiment

put inverted funnel in swamp and move sediment to release methane. Set methane on fire

How are Thaumarcheota and Crenarchaeota related?

Thaum were former Cren

What do most Thaumarcheota do?

oxidize ammonia

What is part of the TACK Superhylum?

Thaumarcheota. Aigararcheota, Crenarcheota, and Korarcheota

What type of temperature-related archaea are Thaumarcheota?

mesophiles

Mesophiles

15-40 degrees (medium loving)

Psychrophiles

15 degrees or less

Mesophilic and Psychrophilic archaea are important for biochemical cycling of () and () in the ocean

carbon and nitrogen

What is special about the Aigarcheota and Korarcheota of teh TACK superphylum?

no actual species has been found of each. Kor only has an rRNA sequence and one genome while Aigar only has one genome available

What is one majro key player of the DPANN superphylum?

Nanoarcheota

What is the only member of the Nanoarcheota?

Nanoarcheum Equitans (one of the smallest organisms on the planet)

how big is Nanoarcheum Equitans?

0.4 micrometers

What are the only genes the Nanoarcheum Equitans has in its genome?

Only genes for replication, transcription and translation, no metabolic genes

Because of this, and the fact that it hangs around Ignococcus Hospitalis all the time, what can Nanoarcheum Equitans be possibly considered?

obligate parasite

What are 3 common features of the DPANN superphylum?

very small in size ( < 1 micrometer), very small genomes (~ 1 Mb), very restricet metabolisms cause them to usually be parasites

What archaea in the Asgard superphylum is most similar (and believed to be the precursor) to Eukaryotes?

Lokiarcheota

what type of temperature archaea are Lokiarcheota?

thermophiles

2 methods of single cell sequencing:

fluorescent and microfluidic

what is the purpose of single cell sequencing?

to amplify DNA and sequence it