Section 11 - The Prokaryotes.pdf - Section 11 The...

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Section 11 The Prokaryotes
Section 11 - The Prokaryotes All information for this section can be found in CHAPTER 27 Masters of Adaptation (p 603-604) 27.1 Structural and functional adaptations contribute to prokaryotic success (p 604-608) 27.2 Rapid reproduction, mutation, and genetic recombination promote genetic diversity in prokaryotes (p 608-612) 27.3 Diverse nutritional and metabolic adaptations have evolved in prokaryotes (p 612-613) 27.4 Prokaryotes have radiated into a diverse set of lineages (p 613-615) 27.5 Prokaryotes play crucial roles in the biosphere (p 618-619) 27.6 Prokaryotes have both beneficial and harmful impacts on humans (p 619-622) Possible Exam Figures Figure 27.3 Gram staining. (p 605)
Prokaryotes = Bacteria and Archaea Overview Most abundant organisms on Earth ~2 billion in a pinch of garden soil !!! ~ 1 billion in 1 mL of seawater !!! More prokaryotes in a handful of soil that ALL THE PEOPLE WHO HAVE EVER LIVED ON EARTH!! All small, single cel ls with simple structure But complex and diverse metabolic capabilities VERY VERY ecologically important Many species New molecular tools are showing just how many there might be on the planet!!!
Prokaryotes have some amazing metabolic capabilities Allowing them to thrive in many environments that would be lethal to most organisms E.g. Oil sands tailings ponds (northern Alberta) Heavy metals, organic chemicals, solvents, processing additives, residual hydrocarbons, covered in a oily slick! High salinity environments E.g Great Salt Lake in Utah salinities 32% higher than seawater great for Halobacterium Very hot, and extreme pH e.g Genus Sulfolobus inhabit sulfur-rich volcanic springs at temps up to 90°C and pH of 3 or less High levels of radiation 3000X fatal dose for humans E.g Deinococcus radiodurans Plus they thrive in all the normal places too!
Concept 27.1 Structural and Functional Adaptations Contribute to Prokaryotic Success
Prokaryotes Earth’s First Life Forms 3.5 BYO Prokaryote FOSSILS (contained within stromatolites) have been identified Prokaryotes may have appeared as long as 4BY ago So - after 3.5 billion years of evolution , what are Prokaryotes like now?? 2BYO 3.5 BYO
Prokaryotes - General Appearance All single cells May aggregate to form clumps or chains (filaments) Diameter typically 0.5 - 5 micrometers ( μ m) small in comparison to most Eukaryotic cells (10-100 μm) Some exceptions e.g. Thiomargarita namibiensis - 750 μm diameter) SHAPE spherical (coccus, cocci), rod-shaped (bacillus, bacilli), or spiral (spirochetes)
ANATOMY OF A BACTERIUM 1. THE CELL WALL
FUNCTIONS of the Bacterial Cell Wall Protection from trauma Shape maintenance Prevents swelling and bursting in a hydrating (hypotonic) environment But doesn’t prevent H 2 O loss in a drying (hypertonic) environment Exposure to brine causes plasmolysis and inhibition of reproduction Hence salting of food Salt cod
PEPTIDO GLYCAN a major component of many bacterial cell walls Framework of modified-sugar polymers cross-linked by short polypeptides Tough provides protection and anchorage for other surface molecules Note: Archaea have cell walls of polysaccharides and proteins - but not peptidoglycan.

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