Bacteria and Archaea - PowerPoint

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					Bacteria and Archaea and
Protists
Chapter 27 Sections 27.1-27.6
Chapter 28 Sections 28.1 and 28.7
Morphology
 Cocci
 Bacilli
 Spirilla
Cell Wall
 What are the functions of the cell wall in
  prokaryotes?
 Maintain cell shape
 Protection
 Prevent bursting in hypotonic
  environment
 Made of peptidoglycan
 Why is some food preserved by salting it?
 Hypertonic environment plasmolyzes
  bacterial cells
Cell Wall Structure
 What is the composition of prokaryotic cell
  walls?
 Peptidoglycan
 Exact components vary among species
 Some antibiotics work by preventing
  formation of cross-links in peptidoglycan
Gram+/Gram-
   Gram positive bacteria:
    ◦   Stains blue/violet
    ◦   Simple cell walls with lots of peptidoglycan
    ◦   Purple/blue stain is trapped in cell wall
    ◦   Less threatening pathogens: tooth decay, strep
        throat
   Gram negative bacteria
    ◦   More complex cell walls with less peptidoglycan
    ◦   Blue dye washes out so they stain pink (first dye)
    ◦   Outer membrane covers cell wall
    ◦   More pathogenic than gram+; typhus gonorrhea
    ◦   Lipopolysaccharides in outer membrane often
        toxic
Adherence
   Capsule:
    ◦ Gelatinous secretion that helps cell adhere to
      host
   Pili:
    ◦ Surface appendages used for conjugation or
      adherence to host
Bacterial Movement
 Flagella
 Spirochetes move via axial helical
  filaments
 Glide via slimy chemical secretion
 Many are capable of taxis in
  heterogeneous environment
Basic Cell
 What does the basic prokaryotic cell look
  like?
 Nucleoid region one circular piece of
  DNA
 Little protein associated with bacterial
  genome
 Bacterial chromosome often called
  genophore
Metabolic Diversity
 What are the four possible modes of
  bacterial nutrition?
 Photoautotrophs
 Chemoautotrophs
 Photoheterotrophs
 Chemoheterotrophs – most bacteria are
  in this group
Reproduction
 Binary fission, no mitosis or meiosis
 What are the methods of genetic
  recombination?
 Transformation
 Conjugation
 Mutations
 What are endospores?
Disease
Exotoxins release poisons such as botulism
 and cholera
Endotoxins seen in outer membrane of
 gram negative bacteria (Salmonella)
Three Groups
 Methanogens
 Extreme halophiles
 Extreme thermophiles
Chapter 28: Protist Diversity
 Unicellular
 Rely on use of nucleus, endoplasmic
  reticulum, Glogi apparatus, and lysosomes
 Nutritionally diverse
    ◦ Photoautotrophs-contain chloroplasts
    ◦ Heterotrophs
    ◦ Mixotrophs-photosynthetic and heterotrophic
   Reproduction and life cycles are highly
    varied-asexual or sexual reproduction
Secondary Endosymbiosis
   Red algae and green algae were ingested
    in the food vacuole of heterotrophic
    eukaryotes and became endosymbionts
Symbiotic relationships
 Photosynthetic dinoflagellates provide
  nourishment to coral polyps that build
  coral reefs
 Wood digesting protists inhabit termite
  guts
Stains violet/blue
Where do photosynthesis and respiration
            take place?

				
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