Bacteria and Archaea and Protists

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Bacteria and Archaea and Protists

• Chapter 27 Sections 27.1-27.6
• Chapter 28 Sections 28.1 and 28.7

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Morphology

• Cocci
• Bacilli
• Spirilla

3
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

4
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

5
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

6
Adherence

• Capsule
• Gelatinous secretion that helps cell adhere to
  host
• Pili
• Surface appendages used for conjugation or
  adherence to host

7
Bacterial Movement

• Flagella
• Spirochetes move via axial helical filaments
• Glide via slimy chemical secretion
• Many are capable of taxis in heterogeneous
  environment

8
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

9
Metabolic Diversity

• What are the four possible modes of bacterial
  nutrition?
• Photoautotrophs
• Chemoautotrophs
• Photoheterotrophs
• Chemoheterotrophs most bacteria are in this
  group

10
Reproduction

• Binary fission, no mitosis or meiosis
• What are the methods of genetic recombination?
• Transformation
• Conjugation
• Mutations
• What are endospores?

11
Disease

• Exotoxins release poisons such as botulism and
  cholera
• Endotoxins seen in outer membrane of gram
  negative bacteria (Salmonella)

12
Three Groups

• Methanogens
• Extreme halophiles
• Extreme thermophiles

13
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

14
Secondary Endosymbiosis

• Red algae and green algae were ingested in the
  food vacuole of heterotrophic eukaryotes and
  became endosymbionts

15
Symbiotic relationships

• Photosynthetic dinoflagellates provide
  nourishment to coral polyps that build coral
  reefs
• Wood digesting protists inhabit termite guts

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Stains violet/blue
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Where do photosynthesis and respiration take
place?