BMSC210 CH4.6 Flashcards
What are some unique characteristics of Archaea?
Ether linkages with branched isoprene chains in cell membrane, lack of peptidoglycan in cell walls
What conditions do extremophilic archaea prefer?
Extreme hot or cold, extreme salinity, or other hostile conditions
Can archaea perform methanogenesis?
Yes
How many major supergroups does the domain Archaea include today?
At least 4
Euryarchaeota
TACK
Asgard
DPANN
Do archaea cause infectious diseases in humans, animals, plants, or microorganisms?
No
What roles do archaea play in the environment?
Cycling of elements
What are lithotrophs?
Autotrophic organisms using CO2 as a carbon source.
What is unique about methanogens?
They can reduce carbon dioxide in the presence of hydrogen, producing methane.
What is the possible connection between methanogens and Mars?
Methanogens may inhabit Mars
Do methanogens require oxygen to produce methane?
No, they are mostly strict anaerobes
What is the class that includes halophilic archaea?
Halobacteria
What type of environment do Halobacteria require?
High concentrations of sodium chloride
What gives salt ponds a distinct purple color?
Halobacteria
What does Halobacterium salinarum produce to give it buoyancy?
proteinaceous gas vesicles
What is the difference between Vac+ and Vac- cells?
Vac+ cells form pink white colonies, whereas Vac- mutants are red and transparent
What role do Archaea play in the oceans?
They play dominant roles in carbon fixation and ammonia oxidation.
What are hydrothermal vents?
Cracks in the earth’s crust where geothermally heated water leaks out.
What are affitins?
Thermostable and acid-resistant proteins
What is the function of affitins?
Bind and neutralize antigens
What are antigens?
Molecules found in toxins or infectious agents that provoke an immune response
Where do Halobacteria live and what is their metabolism?
Extreme salty environments, they use light energy to generate ATP
What is the role of hyperthermophilic archaea in deep sea vent food chains?
They serve as primary producers, converting inorganic compounds into organic matter
What are some similarities between archaea and bacteria?
Lack of nucleus, unicellular, 70S ribosomes, asexual reproduction
What are some structures that archaea can have?
Plasmids, inclusions, flagella, pili
