MICROBIAL LIFE CH 16. Prokaryotes 3.5 billion years Biomass of all prokaryotes = 10x all...

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MICROBIAL LIFE CH 16 Slide 2 Prokaryotes 3.5 billion years Biomass of all prokaryotes = 10x all eukaryotes Handful of soil More prokaryotes than all the humans who have ever lived 1 5 m 10 100 m eukaryotic cells Slide 3 Prokaryotes Impact the World Black Death Tuberculosis, cholera, etc Slide 4 Prokaryotes Slide 5 Slide 6 Slide 7 2 Domains Identifying Relationships 1 type of rRNA found in all prokaryotes & eukaryotes to compare Marker for evolutionary relationships Created the 2 domains of Prokaryotes Bacteria & Archaea Present-day archaea & eukaryotes share a common ancestor Difficult to determine Prokaryote genomes are mosaics of genes Slide 8 2 Domains What are the Main Differences b/w Archaea & Bacteria? rRNA sequences RNA polymerase Introns Antibiotic sensitivity Peptidoglycan in cell wall Membrane lipids Histones associated w/ DNA Conclusions? Slide 9 Prokaryotic Shapes Cocci Spherical Streptococci Strepthroat Staphylococci Bacilli Rod-shaped Diplobacilli Streptobacilli Spiral Shape Vibrios Corkscrew Spirilla Spirochetes Syphilis Slide 10 Prokaryotic Shapes Slide 11 Slide 12 External Structures Slide 13 Slide 14 Slide 15 Slide 16 Motility Slide 17 Flagella movement Respond to chemical or physical signals in the environmenttowards or away Scattered or concentrated at one or both ends How it works Lacks microtubules Rotating rings anchored in the plasma membrane/cell wall Rings provide rotary movement Slide 18 Motility Slide 19 Reproduction & Adaptation Slide 20 Asexual: Binary Fission New generation w/in 2-3 hrs Optimal level is 1 gen/20 minif continued for 3 days, colony would outweigh Earth Reality Repro is limited Exhaust nutrient supply Poison themselves Consumed Competitionantibiotics Slide 21 Reproduction & Adaptation Endospore Made in response to harsh conditions Thick, protective coat that dehydrates & becomes dormant Withstand heat/coldwhatever Conditions improveabsorbs water and resumes growth Interesting Info Remain dormant for centuries Boiling waterno problem Autoclavepressure cooker w/ high pressure steam Food canning industry Slide 22 Reproduction & Adaptation Slide 23 Slide 24 Internal Organization Slide 25 Slide 26 Membrane Specializations Infoldings Cellular respiration Thylakoid membrane PS Genome 1/1000 th as much DNA as eukaryote Plasmids may be resistant to antibiotics Transformation Plasmid Role Direct the metabolism or rare nutrients Resist antibiotics Contingency functions Transfer genes w/in a species and between species Growing problem of antibiotic resistance Slide 27 Internal Organization Slide 28 Ribosomes Smaller than eukaryotic Antibiotics can attack and block protein synthesis, but do not affect eukaryotic ribosomes Useful for medicine Slide 29 Mode of Nutrition 2 Main Sources of Energy: Carbon Energy Autotrophs Make their own Heterotrophs Obtain from organic compounds Slide 30 Metabolic Cooperation Some prokaryotes cooperate Anabaena Photosynthesize & fix nitrogen O2 inactivates nitrogen-fixing enzymes, so They form colonies most cells PS while a few fix nitrogen Biofilms surface-coating colony Signaling recruit Attachment each other & surf. Connections blood vessels Sulfate Bacteria & Methane Archaea Bacteria use waste products & produce compounds that facilitate methane consumption 300 billion kg/year Slide 31 Archaea Environments Abundant in many habitats Extreme environments too Unusual proteins Molecular adaptations Both allow for them to metabolize and reproduce effectively Slide 32 Extreme Environments Extreme Halophiles 15-20% salinityocean is only 3% Extreme Thermophiles Hot water 100C Thermoacidophiles heat & acidic environments Methanogens Anaerobic & give off methane Intestines Slide 33 Halophiles Locations Great Salt Lake Dead Sea Seawater-evaporating ponds used to produce salt Slide 34 Thermophiles Locations Deep-ocean vents high temps Yellowstone National Park acidic pools Slide 35 Methanogens Locations Anaerobic mud Digestive tracts Slide 36 Moderate Archaea Abundant in the oceans Waters below 150 m Equal number of bacteria below 1000 m Slide 37 Types of Bacteria Proteobacteria Gram Subgroup alpha Rhizobium Agrobacterium Subgroup gamma PS Salmonella E. coli Subgroup delta Slimers Hunters at speeds of 600 km/hr Slide 38 Types of Bacteria Chlamydias Common cause of blindness Nongonococcal urethritis or STD Spirochetes Many pathogenic Syphilis Lyme disease Gram +: Some are soil dwellers actinomycetes Cyanobacteria PS Bottom of the food chain Slide 39 PROTISTS Slide 40 Rise of Eukaryotic Cells Eukaryotes evolved from prokaryotes 2 bya 2 Step Process Theory Membrane Infolding Endosymbiosis Slide 41 Membrane Infolding All the membrane-enclosed organelles evolved from inward folds of the plasma membrane of a prokaryotic cell Except mitochondria & chloroplasts Slide 42 Membrane Infolding Slide 43 Endosymbiosis Generated the chloroplasts and mitochondria Prokaryotes that established residence within other, larger prokaryotes Ancestors of mitochondria Heterotrophic prokaryotes that were able to use O2 and release large amounts of energy Ancestors of mitochondria Photosynthetic prokaryotes that may have come to live inside a larger host cell Slide 44 Endosymbiosis Slide 45 Benefits Engulfed cells enjoyed molecules & inorganic ions needed to carry out their biochemical activities Host cells enjoyed increasing proportions of ATP & organic molecules Eventually became interdependentsingle organism Slide 46 Endosymbiosis Evidence Contain DNA, RNA & ribosomes that are similar to prokaryotes Transcribe & translate DNA into polypeptides and enzymes Do something similar to binary fission 2 membranes Alpha proteobacteria mitochondria Cyanobacteria - chloroplasts Slide 47 A Diverse Group Protists Mostly unicellular eukaryotes Basically eukaryotes that are not plants, animals or fungi Categories Algae PS Protozoans Heterotrophic Heterotrophic & Autotrophic Fungus-like Slide 48 A Diverse Group Habitats Most aquatic Damp, terrestrial habitats Moist bodies of hosts What makes them eukaryotic? Slide 49 Diplomonads & Euglenozoans Dips Most ancient 2 nuclei & several flagella Modified mitochondria w/o DNA Anaerobic Giardia intestinalis drinking water contaminated w/ fecessevere diarrhea Slide 50 Diplomonads & Euglenozoans Euglies Heterotrophs, autotrophs, & patho parasites Trypanosoma causes sleeping sickness, spread by the tsetse fly May be fatal if untreated; anxiety, insomnia, sleepiness, mood changes, fever, headache Euglena 1 or 2 flagella PSmay also absorb nutrients as heterotrophs Slide 51 Alveolates Characterized by membrane-enclosed sacshomeostasis Dinoflagellatesaka Dinos Common of marine & FW phytoplankton Heterotrophic 2 cellulose plates 2 flagella spin Dino bloomsturn water colors & release toxinsmassive fish kills Slide 52 Alveolates Apicomplexans Parasites Complex of specialized cells used for entering a host cell Plasmodium causes malaria Enters and feeds on red blood cells Spread by mosquitoes Ciliates Have cilia Free-living; macro- and micronucleus Paramecium Slide 53 Stramenopiles Hairy flagellum paired w/ a smooth flagellum Water molds Fungus-like, aid in decomposition Downy mildewscauses late blight in potatoes Diatoms PS algae; FW or SW Cell wall that contains silica Bottom of the food chain Slide 54 Stramenopiles Brown algae Largest & most complex algae Multicellular and marine Seaweeds Slide 55 Amoebozoans Characterized by their pseudopodia Lobe-shaped extensions of the cell for movement Gather food Amoebas Free-living: mud at the bottom of a pond/ocean Parasitic: amebic dysentery Slide 56 Amoebozoans Slime Molds Plasmodial moist, decaying matter Many nuclei w/in one mass of cytoplasm plasmodium Weblike form Phagocytosis w/ pseudopodia Reproductive structures for tough times Cellular moist, decaying matter Solitary amoeboid cells Swarm to form a slug-like aggregate that wanders Dry, and produce repro stalk spores Slide 57 Red Algae & Green Algae Red Warm, coastal waters of tropics Red pigment that masks chlorophyll Soft-bodies Green Chlamydomonas unicellular, FW lakes and ponds Uses 2 flagella Volvox - colonial Slide 58 Red Algae & Green Algae Alternation of Generations Slide 59 Multicellularity ARISES! Unicellular vs Multicellular First ancestor unicellular protists that lived in colonies Colony to Locomoter/Food-synthesizing cells to organisms that produces gametes 3 Lineages from Ancestral Eukaryote 1 to brown algae 1 to fungi and animals 1 to red algae, green algae, and plants