Prokaryotes - Lecture notes 2 PDF

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Lecture notes which cover prokaryote description and development....

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Prokaryotes Monophyletic Tree: Cosisting of the ancestors species and all its decedents CQ: See physical notes in socy note book Prokaryotes are not a monophyletic group, we discuss them together for convenience I. Prokaryotes -Bigger than eukaryote biomass -100 billion species of bacteria -10,000 have been described -6 lbs of your body weight is bacteria Highest concentration of bacteria on your forearm, least behind your ear *Pro-karyote -> “No-nut” - before the nucleus A. Features 1. Single celled 2. small 3. Single circular chromosome a. Plasmids 4. Cells wall - Peptidoglycan 5. Moves Why are prokaryotes so successful? 1. Exponential pop growth a. Asexual b. 1-3 hours to reproduce c. mutations 2. Endospores (Resistant stages) a. Survive centuries - billions of y/o 3. Conjugation (Bacterial “sex”) a. plasmids *Not membrane bound II. Origin of Life -Oldest known fossils of fossils = 3.5 byo -Resembles prokaryote 1. Cyanobacteria (3.5bya) Photosynthesis a. Produced surplus of O2 in the atmosphere b. Led to rust being produced c. Around 2.5 bya = “oxygen catastrophe” -Extinction of anaerobic bacteria -Led to glacier event...