Topic 3 Review - Archaea Flashcards
(39 cards)
What were the first archaea discovered?
methanogens
Where would you find Halobacterium salinarium?
“salt lovers”
- Dead sea
Where would you find Pyrococcus furiosus?
Pyro = temperature
- hydrothermal vents
Where would you find Picrophilus oshmiae?
Picro = acid
- volcanic regions
Where would you find methanogenium frigidum?
Methan = methane generator
Frigid = low temp
- Antarctica
Typical size?
0.5-5um
Shapes of archaeal cells
- rods, cocci, spirals
- pleomorphic (irregular)
- Thermoproteus (Rectangles)
- Haloquadratum (squares)
What are characteristics of the cytoplasm?
- single circular chromosomes and lack a mem. bound nucleus
- hitsones
- microcompartments/inclusion bodies like bacteria
- DNA enzymes similar to euk.’s
What are histones?
Positively charged proteins that DNA wrap around
Do archaeal cells have an outer membrane?
No
Do archaeal cells have a plasma membrane?
Yes
How is the plasma membrane bilayer constructed in Archaea?
- Glycerol-1-phosphate
- Phytanyl side chains
- ether linkages
Why is the monolayer for Archaea so important?
Stability
What linkages do archaea cells have that euk.’s and bacteria dont?
Ether linkages
What properties would you see of Archaea living in high-temperature environments?
Biphytanyl monolayer
What are archaea cell walls composed of?
Pseudomurein
What is the difference between bacterial and archaeal cell walls?
Bacteria:
- NAG/NAM
- beta 1-4 linkages
Archaea:
-NAG/NAT
- beta 1-3 linkages
What is the function of cannulae in archaea?
link cells together
What is the main difference between bacterial and archaeal flagellum?
Bacteria:
- PMF as energy
Archaea:
-ATP
What are the four major phyla of Archaea?
- Euryarchaeota
- Crenarchaeota
- Thaumarchaeota
- Nanoarchaeota
Where do Crenarchaeota live?
Extreme envrionments:
- thermophiles (high temp.)
- acidophiles (low pH)
- barophiles (high pressure)
What adaptations do archaea possess to sustain high temperatures?
- tetraether lipid monolayers
- modified proteins
- chaperone protein complexes
- thermostable DNA-binding proteins
What do these modified proteins in Archaea consist of?
- alpha-helical regions
- salt bridges
- more arginine/tyrosine
- less cysteine/serine’s
What are euryarchaeota?
Halophiles (salt lovers)
