unit 4: archaebacteria

Kingdom Archaea: general description

\- possibly the oldest organisms on earth \n -live in extreme enviornments \n -unicellular, prokaryotic \n -visaully look similar to bacteria

Methanogens

anerobic, produce almost all the methane gas in the world \n 1/3 methane comes from methanogens in the guts of herbivores, can be found in: marine and fresh-water sediments, bogs and deep soils, intestinal tracts of animals and sewage treatment facilities

Halophiles

"salt-loving" archaea that live in environments that have very high salt concentrations such as the Dead Sea, the great salt lake or evaporating ponds of seawater where the salt concentration is very high. these prokaryotes require salt for growth and will not grow at low salt concentrations, their cell walls, ribosomes and enzymes are stabilised by Na+

Thermoacidophiles/or extreme thermophiles:

Exist in hot, acidic environments \n require a very high temperature for growth (80 degrees to 105 degrees), some require very low pH's for survival (ex. 2 and below), Their membranes and enzymes are unusually stable at high temperatures, Most of these Archaea require elemental sulfur for growth, Found in hot, sulfur-rich environments usually associated with volcanism, such as hot \n springs, geysers and fumaroles in Yellowstone National Park, and thermal vents ("smokers") and cracks in the ocean floor

Psychrophiles

Live in glacial ice or permafrost in or near the Arctic or \n Antarctic \n Their existence suggests the possibility that life could exist on \n other planets which have cold/frozen environments

how do archaebacteria help in scientific research

archaeabacteria are helpful in scientific research since they can withstand conditions that \n kill other organisms

how do enzymes from thermophiles help with archaebacteria

enzymes from thermophiles can be used for a genetic technology called PCR

how do enzymes from psycrophiless help with archaebacteria

Enzymes from psychrophiles have natural antifreeze molecules that can be used when \n attempting to preserve other types of cells without causing them to freeze over

Fungi like protists (slime and water molds)

**are heterotrophic decomposers who feed on the surface they grow on, uni/multicellular, may be motile at some point in life cycle and non motile during others, reproduce sexually using spores, can cause major allergic reaction, they like cool moist places**

Animal like protists (protozoa)

feed using vacuoles, act as parasites in larger organisms, unicellular, various ovoid, amoebic, lady-slipper like, may have cilia, can move with cilia, flagella or have pseudopod movement, usually asexaul reproduction.

Plant like protists (algae)

are autotrophic (photosynthetic), unicellular, have chloroplasts, move with flagella or not at all, usually asexual, sometimes sexual (conjugation), not very pathogenic to humans