1. Domain Prokarya/Archaea Kingdom Archaea

2. Discovery of Archaea Prior to 1977 they were considered bacteria
1977 Carl Woese and George Fox proposed a new domain/kingdom
S rRNA and 18S rRNA sequences justify separation
2003 genome sequence analysis justifies kingdom/domain status

3. Multicellular Animals
Shifting Kingdoms
Lumpers
Plantae
Monera
Archaea
Splitters 2 3 5 6 8
Bacteria
Archaebacteria
Archezoans
Euglenoids
Chrysophytes
Green Algae
Brown Algae
Red algae
Slime Molds
True Fungi
Bryophytes
Tracheophytes
Protozoans
Myxozoans
Multicellular Animals

4. How Many Kingdoms? Extant 8 5 3 2 Extinct 1 Long Time with
Multicellular Animals
Myxozoans
Protozoans
Tracheophytes
Bryophytes
True Fungi
Slime Molds
Red algae
Brown Algae
Green Algae
Chrysophytes
Euglenoids
Archezoans
Archaebacteria
Bacteria 8 5 3 2
Extinct 1
Long Time with
Prokaryotes only
The prokaryotes are a?
Grade!
Original Cell

5. Archaea Ancient origin, but appreciated more recently
Somewhat more advanced than Bacteria
Extremophiles-90°C pH2 25M anaerobic -4°C Antarctica!
Methanogens
Halophytes
Sulfur metabolism
DNA binding proteins (but not histones)
Unicellular, colonial, filamentous
Bacillus, coccus, spirillum, plate-like, etc.
Size: 0.1 to 15 µm diam. x 200 µm long

6. Archaea Cladogram Extant Genera Crenarchaeota Euarchaeota to Eukarya
Haloferox
Halococcus
Methanococcus
Methanobacterium
Thermofilum
Haloarcula
Pleurophillus
Pyrococcus
Thermococcus
Archaeoglobus
Ferroglobus
Pyrobaculum
Thermoproteus
Sulfolobus
Desulfurococcus
Thermoplasma
Pyrodictium
Thermo-
coccales
Thermoplasmales
Thermoproteales
Igneococcales
Halobacteriales
Methanogenales
Archaeoglobales
Sulfolo-
hales
S+org->H2S+CO2
Hydrothermal vents
MethanogenR lactate->H2+CO2
Autotroph H2+SO4-2->H2S
Halophilic
Chemoheterotroph
resp O2
Chemoautotroph
Light->bacteriorhodopsin->ATP
Methanogens-anaerobes
CO2+H2->F420 fluorescent ->CH4
Ruminant gut flora
Marshes, landfills
Crenarchaeota
Euarchaeota
Thermophilic
Acidophilic
Autotrophic (CO2)
Sulfur + H2 -> H2S + H+
-O2 Heterotrophic (CH2O)
Sulfur+CH2O->CO2+H2S
+O2 Heterotrophic (TCAR)
Sulfur + O2 -> H2SO4
to Eukarya
to Bacteria
Original Cell

7. Prokaryotic Growth Cells are generally very small
Cells may double in size but only before binary fission
Growth mostly in terms of cell number or colony size, etc.
Doubling time in cell numbers may be 20 minutes in ideal conditions
Could quickly take over the earth if conditions could remain ideal
Very competitive in ideal environments
Ultimate survivors billion years!

8. Cell Structure: Boundary
Thermoplasma
cell membrane bilayer
phosphoglycerohydrocarbon, etc.
sulfo- or glyco-glycerohydrocarbon
(ether link not ester link)
transport proteins
cytosol
regulates input/output
Gram Positive
Methanobacterium
Gram Negative
Thermoproteus
cell wall-glycan
(no muramic acid)
prevents bursting
turgor pressure
thin
surface layer
glycoprotein
releases dye

9. Homeostasis - metabolism
Facultative and Obligate Anaerobes and Aerobes
Nutrition Mode
Energy Source
Carbon Source
Photoautotroph
Light
CO2
Chemoautotroph
Inorganic chem
Photoheterotroph
Organic chem
Chemoheterotroph
Chemoautotroph acetyl-CoA or reverse TCA to fix CO2 Photoautotroph Calvin Cycle (Methanococcus, Pyrococcus)
Chemoheterotroph citric acid cycle, fermentation
Sulfur transporters used to drive ATP synthesis

10. How do Archaea tolerate the heat?
Proteins stabilized by more ionic bridges between amino acid r-groups and more-hydrophobic core amino acids
Heat shock protein (chaperonins) refold denatured proteins…Pyrococcus 121°C for 1 hour!
DNA depurination reduced by presence of 2,3-diphosphoglycerate.
DNA supercoiling by reverse gyrase reduces denaturation
Sac7d in Sulfobolus is a minor groove protein increases the melting temperature by 40°C
Histone-like proteins help stabilize DNA as well
Heat-resistant di-bi-phytanyl diether lipid membranes (monolayer) prevent delamination of membrane

11. Cell Membrane Structure
Composed of diglycerides
R group may be phosphate, sulfate, or sugar
Long chain branched hydrocarbon (not fatty acid)
Hydrocarbons may be C20 or C40
If C20, the membrane is a bilayer: O R
If C40, the membrane is a monolayer O R
In some species, the membrane is a mixture of both C20 and C40 diglycerides forming a mixed mono-/bi-layer