Presentation is loading. Please wait.

Presentation is loading. Please wait.

 MICROBIAL LIFE CH 16. Prokaryotes  3.5 billion years  Biomass of all prokaryotes = 10x all eukaryotes  Handful of soil…  More prokaryotes than all.

Similar presentations


Presentation on theme: " MICROBIAL LIFE CH 16. Prokaryotes  3.5 billion years  Biomass of all prokaryotes = 10x all eukaryotes  Handful of soil…  More prokaryotes than all."— Presentation transcript:

1  MICROBIAL LIFE CH 16

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 μ m …10 – 100 μ m eukaryotic cells

3 Prokaryotes  Impact the World  Black Death  Tuberculosis, cholera, etc

4 Prokaryotes

5

6

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

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?

9 Prokaryotic Shapes  Cocci  Spherical  Streptococci  Strepthroat  Staphylococci  Bacilli  Rod-shaped  Diplobacilli  Streptobacilli  Spiral Shape  Vibrios  Corkscrew  Spirilla  Spirochetes  Syphilis

10 Prokaryotic Shapes

11

12 External Structures

13

14

15

16 Motility

17  Flagella – movement  Respond to chemical or physical signals in the environment…towards 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

18 Motility

19 Reproduction & Adaptation

20  Asexual:  Binary Fission  New generation w/in 2-3 hrs  Optimal level is 1 gen/20 min…if continued for 3 days, colony would outweigh Earth  Reality  Repro is limited  Exhaust nutrient supply  Poison themselves  Consumed  Competition…antibiotics

21 Reproduction & Adaptation  Endospore  Made in response to harsh conditions  Thick, protective coat that dehydrates & becomes dormant  Withstand heat/cold…whatever  Conditions improve…absorbs water and resumes growth  Interesting Info  Remain dormant for centuries  Boiling water…no problem  Autoclave…pressure cooker w/ high pressure steam  Food canning industry

22 Reproduction & Adaptation

23

24 Internal Organization

25

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

27 Internal Organization

28  Ribosomes  Smaller than eukaryotic  Antibiotics can attack and block protein synthesis, but do not affect eukaryotic ribosomes  Useful for medicine

29 Mode of Nutrition  2 Main Sources of Energy:  Carbon  Energy  Autotrophs  Make their own  Heterotrophs  Obtain from organic compounds

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

31 Archaea Environments  Abundant in many habitats  Extreme environments too  Unusual proteins  Molecular adaptations  Both allow for them to metabolize and reproduce effectively

32 Extreme Environments  Extreme Halophiles  15-20% salinity…ocean is only 3%  Extreme Thermophiles  Hot water – 100ºC  Thermoacidophiles – heat & acidic environments  Methanogens  Anaerobic & give off methane  Intestines

33 Halophiles  Locations  Great Salt Lake  Dead Sea  Seawater-evaporating ponds used to produce salt

34 Thermophiles  Locations  Deep-ocean vents – high temps  Yellowstone National Park – acidic pools

35 Methanogens  Locations  Anaerobic mud  Digestive tracts

36 Moderate Archaea  Abundant in the oceans  Waters below 150 m  Equal number of bacteria below 1000 m

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

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

39  PROTISTS

40 Rise of Eukaryotic Cells  Eukaryotes evolved from prokaryotes 2 bya  2 Step Process – Theory  Membrane Infolding  Endosymbiosis

41 Membrane Infolding  All the membrane-enclosed organelles evolved from inward folds of the plasma membrane of a prokaryotic cell  Except mitochondria & chloroplasts

42 Membrane Infolding

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

44 Endosymbiosis

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 interdependent…single organism

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

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

48 A Diverse Group  Habitats  Most aquatic  Damp, terrestrial habitats  Moist bodies of hosts  What makes them eukaryotic?

49 Diplomonads & Euglenozoans  Dips  Most ancient  2 nuclei & several flagella  Modified mitochondria w/o DNA  Anaerobic  Giardia intestinalis – drinking water contaminated w/ feces…severe diarrhea

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  PS…may also absorb nutrients as heterotrophs

51 Alveolates  Characterized by membrane-enclosed sacs…homeostasis  Dinoflagellates…aka Dinos  Common of marine & FW phytoplankton  Heterotrophic  2 cellulose plates  2 flagella spin  Dino blooms…turn water colors & release toxins…massive fish kills

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

53 Stramenopiles  Hairy flagellum paired w/ a smooth flagellum  Water molds  Fungus-like, aid in decomposition  Downy mildews…causes late blight in potatoes  Diatoms  PS algae; FW or SW  Cell wall that contains silica  Bottom of the food chain

54 Stramenopiles  Brown algae  Largest & most complex algae  Multicellular and marine  Seaweeds

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

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

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

58 Red Algae & Green Algae  Alternation of Generations

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


Download ppt " MICROBIAL LIFE CH 16. Prokaryotes  3.5 billion years  Biomass of all prokaryotes = 10x all eukaryotes  Handful of soil…  More prokaryotes than all."

Similar presentations


Ads by Google