Bacteria, Archaea, and Eukarya

• the 3 main domains are bacteria, archaea, and eukarya
• bacteria and archaea are prokaryotes whereas eukarya are eukaryotes
• prokaryotes live in many and sometimes extreme environments
• most microbes are not pathogenic (disease causing)
• bacteria attach to surfaces via biofilm
• prokaryotes reproduce via binary fission
• bacteria have circular DNA and plasmids
• transformation is when cells absorb material from the environment
• transduction is when a cell is infected by a virus that implants information
• conjugation is when cells connect to spread information between them
• genetic info moves from the donor cell to the recipient cell
• coccus = spheres
• spira = spirals
• bacilli = rods
• colonies can form pairs (di), strings (strep), or clusters (staph)
• bacteria have a unique cell wall made up of peptidoglycan
• gram+ bacteria have a big cell wall without lipids that does stain purple and only one cell membrane
• gram- bacteria have a small cell wall with lipids that does not stain and is surrounded by 2 cell membranes
• autotrophs self synthesize carbon bonds
• heterotrophs get carbon bonds from other organisms
• phototrophs get their energy from sunlight
• chemotrophs get their energy from organic or inorganic molecules
• organotrophs have an organic electron source
• lithotrophs have an inorganic electron source
• nitrogen fixers convert nitrogen to ammonia
• nitrifers convert ammonia to nitrite or nitrate
• denitrifers convert nitrate to nitrogen
• cyanobacteria were the first photosynthesizers
• spirochete drill into places with their spiral shape
• chlamydias are obligate parasites
• proteobacteria are very diverse
• firmicutes utilize endospores to protect themselves
• actinobacteria supply us with many antibiotics
• archaea have a unique cell wall
• 56% of archaea DNA is unique to them
• archaea plasma membranes have different lipids
• archaea and eukarya both have histones in their DNA
• acidophiles like pH below 3
• alkaphiles like pH above 9
• thermophiles like 60-80 degrees Celcius