Archaea

Question 1

taxa nomenclature for archaea

Answer 1

phyla:
1. Crenarchaeota (extremophile)
2. Euryarchaeota (extremophile)
3. Kor(y)archaeota (methanogens)
4. Nanoarchaeota (extremophile)

Question 2

Common features (properties to classify archaea)

Answer 2

– Lack true Peptidoglycan: Cell membrane lipids have branched hydrocarbon chains
-Reproduce by Binary Fission or Budding
-Most are cocci, bacilli, or spiral forms; pleomorphic forms exist
-Not known to cause disease: However, often in moderate habitats (i.e. biomass in Antarctic)

Question 3

what is extremophiles?

Answer 3

-Require extreme conditions to survive: Temperature, pH, and/or salinity
-Prominent members: Thermophiles, Halophiles

Question 4

what is thermophiles?
hyperthermophiles?
example of thermophiles?

Answer 4

(extremophiles)
-thermophiles: DNA, RNA, cytoplasmic
membranes, and proteins do not function properly below 45°C
–Hyperthermophiles: require temperatures over 80°C
-Most Crenarchaeota, some Euryarchaeota

Question 5

what are halophiles?

Answer 5

(extremophiles)
-All Euryarchaeota
–Inhabit extremely saline habitats
–Depend on greater than 9% NaCl (~17-23%) to maintain integrity of cell walls (holds H2O well)
–Many contain red or orange pigments to protect from visible and UV light

Question 6

methanogens:

Answer 6

-Largest group of archaea
-Creates methane with CO2, H2 or organic acids
-Convert organic wastes in pond, lake, and ocean
sediments to methane
–One of primary sources of environmental methane
-Some live in colons of animals
-Industrial application: Sewage treatment or burn for heat