BIO 200 Lecture Notes - Lecture 12: Flagellum, Spirillum, Cyanobacteria
10 Nov 2017
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Document Summary
We only know about 1-10% of the extant prokaryotes. We didn"t know we were archaeans until recently. The bacteria in the archaea (prokaryotes) are the oldest and simplest lifeforms -> early photosynthetic bacteria produced oxygen -> changed atmosphere to oxidizing environment: differentiate the prokaryotes from the eukaryotes. Thermatoga maritima are achaean in origin gene sharing) The prokaryote tree may be more of a web: cell wall ubiquitous (peptidoglycan or psuedomurein) Shape (rod, sphere, spirals/coccus, bacillus, or spirillum) Metabolism (how an organism obtains nutrients) -> prokaryotes have a wide variety of metabolism styles. Oxygen: aerobes = need oxygen, anerobes = poisoned by oxygen (obligate, facultative, and aerotolerant) Obligate aerobes must have oxygen, obligate anaerobes must not have oxygen, facultative anaerobes can move between aerobes and anaerobes, Aerotolerant anaerobes do not need oxygen and aren"t harmed. How they acquire nutrients: autotrophs self feeders, heterotrophs other feeders.
