Archaea

Question 1

What are thermophiles?

Answer 1

Thermophiles - archaea/bacteria that can survive at temperatures > 60C.

Question 2

What are hypothermophiles?

Answer 2

Hypothermophies - archaea that car survive in conditions > 90C.

Question 3

What are psychrophiles?

Answer 3

Psychrophiles - archaea that live in deep, permanently-cold water.

Question 4

What are halophiles?

Answer 4

Halophiles - archaea that live in hypersaline pools.

Question 5

What are acidophiles?

Answer 5

Acidophiles - archaea that live/generate very acidic environments/compounds.

Question 6

What are methanogens?

Answer 6

Methanogens - archaea that generate methane.

Question 7

What compounds are metabolised by methanogens to generate methane?

Answer 7

CO2, H2, formate, acetate, and other small molecules.

Question 8

What are cellular membrane traits of archaea that differ from those of bacterial cells?

Answer 8

1. L-glycerol linked side chains via ether bonds (bacteria use D-glycerol linked side chains via ester bonds)
2. Lipids lack FA’s found in bacteria + eukaryote - have side chains of repeating isoprene units instead that link to form isoprenoid, which enhances stability
3. Ends of side chains for some extremophiles may link up to form a cyclic structure which strengthens the membrane

Question 9

What are cellular wall traits of archaea that differ from those of bacterial cells?

Answer 9

1. Pseudopeptidoglycan (vs bacterial peptidoglycan)

2. N-acetylalosaminuronic acid (vs bacterial N-acetyl muramonic acid (NAM))

Question 10

What is a helpful feature of pseudopeptidoglycan in archaea cell walls?

Answer 10

Pseudopeptidoglycan is not affected my lysozyme nor penicillin.

Question 11

What are some features of phototrophic archaea?

Answer 11

1. Do not use chlorophyll (non-photosynthetic)

2. Use bacteriohodospin

Question 12

What is bacteriohodspin and how does it work?

Answer 12

Bacteriohodospin - retinal-based ion pump coupled to ATP synthesis that gives archaea their purple colour.