bio 14 - prokaryotes

• archaebacteria - kingdom under domain archaea
• eubacteria - kingdom under domain bacteria
• prokaryota and eukaryota - 2 superkingdoms
• in plasma membrane bacterial lipids are unbranched
• in plasma membrane archaeal lipids are branched
• D-glycerol for bacteria glycerol
• L-glycerol for archaeal glycerol
• bacteria connected to glycerol by ester linkages
• archaea connected to glycerol by ether linkages
• Bacteria have peptidoglycan
• Archaea lack peptidoglycan
• bacteria - single origin
• archaea - multiple origin, same with eukaryotes
• bacteria - mRNA is translated directly to protein
• archaea - transcription translation coupling (ttc)
• archaea - "ancient" bacteria
• archaebacteria - were discovered in Yellowstone National Park's hot springs and geysers.
• archaea - prokaryotes that have diverged very early from bacteria that are more closely related to eukaryotes
• archaea - lack peptido, extreme environment, unicellular, some have flagella
• methanogens - release methane (CH4) as a waste product
• methanogens - Many live in mud at the bottom of lakes and swamps because it lacks oxygen
• methanogens - Some live in the intestinal tracts of animals to help break down food
• thermoacidophiles - Live in the dark, without oxygen, live in superheated water with temperatures reaching 750 deg F, Prefer environments that are very acidic (between pH of 1-3)
• thermoacidophiles live in a chemical soup of hydrogen sulfide (H2S) and other dissolved minerals (rotten egg smell)
• The interior layers of the Earth are made up of many different types of metals (iron, copper).
• black smokers - The black color is caused by a chemical reaction of the metals with the ocean water. In extreme temperatures and pressures, this is where some thermoacidophiles like to live.
• halophiles - can live in water with salt concentrations exceeding 15% cannot below 10%
• halophiles - Found in salt flats and evaporation ponds.
• pinkish-red - color of where halophiles live
• bacterioruberin - protection from sunlight; bright red carotenoid pigment protects the cells from intense solar radiation
• Bacteriorhodopsin - use sunlight for energy, produce their own ATP using this pigment.
• Desulfurococcales, Barophilic Hyperthermophiles, Sulfolobales: composes the Crenarchaeota
• Desulfurococcales - Lack cell walls, but have elaborate S-layer, reduce sulfur at higher temperatures
• Desulforococcus mobilis - desulfurococcales found in Hot springs
• Ignicoccus islandicus - desulfurococcus that is a Marine organism
• S-layer - part of the cell envelop composed of identical glycoproteins, barrier function, protection from bacteriophages, phagocytosis, resistance to low pH, adhesion
• 

  Barophilic hyperthermophiles - Grow near hydrothermal vents on the ocean floor
• A common feature of barophilic hyperthermophiles is the black smoker.
• Crenarchaeotes that are vent-adapted:

  • Pyrodictium abyssi and Pyrodictium occultum
•  Sulfolobus solfataricus - A "double extremophile", grows at 80°C and pH 3, oxidizes hydrogen sulfide to sulfuric acid