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Unformatted text preview: Life responds to stimuli- Early prokaryotes had pigments to detect infrared radiation. Add a few billion years and some wavelengths, and you get PHOTOSYNTHESIS = oxygen! Free oxygen prevents spontaneous organic compound formation, but cell membranes protect, and cells are able to make use of the oxygen through aerobic respiration. This allows for the possibility of larger, more energy consuming life forms. Evidence of photosynthetic prokaryotes found in fossilized stromatolites (old mats.) *Current Atmosphere* Nitrogen = 78% Oxygen = 21% Carbon Dioxide = .03% Prokaryotes are still alive and successful today. Microorganisms are any single celled organisms that are too small to be seen without a microscope. ALL prokaryotes, and some eukaryotes. DOES NOT signify any evolutionary relationship. Three Domain Classifications of Organisms 1. Bacteria 2. Archaea 3. Eukarya-Domain bacteria and archaea contain all members of prokaryotes. -In general, prokaryotes are much smaller than eukaryotes. -(Bacteria are the smallest living organism) Characteristics of Prokaryotic Cells: NSCRG!! 1. No membrane-bound nucleus 2. Single chromosome with no associated proteins; many species also contain plasmids 3. Cell wall present in most species 4. Reproduction mainly by prokaryotic fission 5. Great metabolic diversity among species. General Prokaryote Body Plan: DCPCOBP 1. DNA in nucleoid region 2. Cytoplasm with ribosomes 3. Plasma membrane 4. Cell wall 5. Outer capsule 6. Bacterial flagellum 7. Pilus – allows bacteria to stick to surfaces. General Shapes (Prokaryotes)-Coccus – round-Bacillus – rod-Spririllum – spiral *Prokaryotes reproduce asexually by fission, sometimes in as little as twenty minutes. DOMAIN BACTERIA CGGCS *Oldest origin, most common, and diverse prokaryotic cells. * Five major groups…this causes a problem… 1. Cyanobactera *Pond scum *Photoautotroph = sunlight = photosynthesis *May be origin of chloroplasts *Not to be confused with green algae, a eukaryote 2. Gram Positive *TURN PURPLE B/C OF CELL WALL! *Chemoheterotroph = get food source from something that makes it for them *Some can form endospores – dormant stage containing DNA encased in a protective capsule. Ex= anthrax. 3. Gram Negative Bacteria *TURN LIGHT PINK B/C NO CELL WALL! *Chemoheterotrophs *Genus salmonella and genus Escherichia = bacillus shaped. *Genus neisseria = coccus shaped 4. Chlamydia *Parasite *Needs to steal ATP *Some cause blindness, while some are STDs *Coccus shaped 5. Spirochetes *Spirillium shaped *One type causes syphilis *Pathogen – something that causes diseases *Pathogenic bacteria – causes disease, but 99.9% of bacteria are harmless or beneficial....
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