1. Diversity of Life - Prokaryotes

3. What are prokaryotes?
- a type of organism lacking a membrane-enclosed nucleus and membrane-enclosed organelles.

4. What are prokaryotes?
- a type of organism lacking a membrane-enclosed nucleus and membrane-enclosed organelles.
Bacteria

5. What are prokaryotes?
- a type of organism lacking a membrane-enclosed nucleus and membrane-enclosed organelles.
Bacteria Archaea

6. What are the features of prokaryotes?
Look at:
Cell surfaces
Internal organization
Nutritional/metabolic adaptations

7. What are the features of prokaryotes?
Cell Surfaces
-one feature which determines the kind of bacterium
being dealt with
-made up peptidoglycan
Sugars (polymers)
Polypeptides

8. What are the features of prokaryotes?
Cell Surfaces
-one feature which determines the kind of bacterium
being dealt with
peptidoglycan layer
plasma membrane
Cell wall = peptidoglycan layer

9. What are the features of prokaryotes?
Cell Surfaces
-one feature which determines the kind of bacterium
being dealt with
lipopolysaccharide
Outer membrane
peptidoglycan layer
plasma membrane
Cell wall = peptidoglycan layer
Cell wall = peptidoglycan layer
+ outer membrane

10. What are the features of prokaryotes?
Cell Surfaces
-one feature which determines the kind of bacterium
being dealt with
lipopolysaccharide
Outer membrane
peptidoglycan layer
plasma membrane
Cell wall = peptidoglycan layer
Cell wall = peptidoglycan layer
+ outer membrane
Gram positive
Gram negative

11. What are the features of prokaryotes?
Gram positive
Gram negative

12. What are the features of prokaryotes?
Cell surfaces and infection
-lipopolysaccharide layer - can produce toxins
-outer membrane - protects bacteria from host’s immune system
- outer membrane - protects bacteria from antibiotics

13. What are the features of prokaryotes?
Internal structure
cell wall
nucleoid region
plasmids
plasma membrane
ribosomes
capsule
chromosome
Prokaryotic cell

14. What are the features of prokaryotes?
Internal structure - what do the structures do?
Cell wall - provides physical protection, maintains shape in different salinities
Capsule - sticky, polysaccharide or protein - protection from host’s immune system
Plasma membrane - acts as a selective chemical barrier
Chromosome - a ring of DNA that carries all the necessary genetic information
Nuceloid region - area of the cell containing the chromosome
Plasmids - small rings of DNA - function in ‘emergency’ situations
Ribosomes - site of protein synthesis in the cell

15. What are the features of prokaryotes?
Nutritional and metabolic adaptations
Ways of obtaining energy
Autotroph - use only CO2 as a carbon source
Heterotroph - need one organic nutrient (e.g. glucose)
Phototrophs - use light as a source of energy
Chemotrophs - use chemicals as a source of energy

16. What are the features of prokaryotes?
Nutritional and metabolic adaptations
Ways of obtaining energy
Energy Carbon
Mode of nutrition source source
Autotrophs
Photoautotroph Light CO2 Chemoautotroph Inorganic CO chemicals
Heterotrophs
Photoheterotroph Light Organic compounds
Chemoheterotroph Organic Organic compounds compounds

17. What are the features of prokaryotes?
Nutritional and metabolic adaptations
Relationship to Oxygen
Facultative
Obligate
None
Need O2 for cellular respiration
Use O2 for cellular respiration but can grow without it
Poisoned by O2
-use other chemicals
Aerobes
Anaerobes

18. What are the features of prokaryotes?
Nutritional and metabolic adaptations
Relationship to Nitrogen N2
NH3
Amino acids
Proteins
Plant can’t fix N2

19. Classification of Prokaryotes
What features separate the Bacteria from the Archaea?
Characteristic Bacteria Arachaea
Peptidoglycan yes no
Reponse to growth growth
antibiotics inhibited not inhibited
Growth above no some species
100ºC
See Table 27.2 in your book

20. Classification of Prokaryotes
Alpha
Beta
Proteo-
bacteria
Gamma
Delta
Epsilon
Chlamydias
Spirochaetes
Cyanobacteria
Gram positive bacteria
Archaea

21. Classification of Prokaryotes
Alpha
Gram positive
Beta
Gram negative
Proteo-
bacteria
Gamma
Delta
Epsilon
Chlamydias
Spirochaetes
Cyanobacteria
Gram positive bacteria
Archaea

22. Classification of Prokaryotes
Alpha Proteobacteria
-e.g. Rhizobium - nitrogen fixing in plant roots
Beta Proteobacteria
-several soil bacteria
Gamma Proteobacteria
-some pathogens - Salmonella (food poisoning)
Legionella (Legionnaire’s disease)
Vibrio cholerae (Cholera)
Delta Proteobacteria
-several soil bacteria
Epsilon Proteobacteria
-gastrointestinal infections

23. Classification of Prokaryotes
Chlamydias
-venereal disease

24. Classification of Prokaryotes
Chlamydias
-venereal disease
Spirochaetes
-disease organisms
Treponema pallidum - syphillus
Borrelia burgdorferi - Lyme disease

25. Classification of Prokaryotes
Gram positive Bacteria
-very diverse group
Some familiar ones:
Streptomyces - antibiotic production

26. Classification of Prokaryotes
Gram positive Bacteria
-very diverse group
Some familiar ones:
Streptomyces - antibiotic production
Bacillus anthrax - anthrax

27. Classification of Prokaryotes
Gram positive Bacteria
-very diverse group
Some familiar ones:
Streptomyces - antibiotic production
Bacillus anthrax - anthrax
Streptococcus - respiratory disease

28. Classification of Prokaryotes
Cyanobacteria - only prokaryotes with plant-like
photosynthesis

29. Classification of Prokaryotes
Archaea - differ from bacteria in several ways but have no
peptidoglycan
Common in extreme conditions
Thermophiles - live at extreme temperatures
(>100ºC)
Pyrolobus
-in deep sea vents

30. Classification of Prokaryotes
Archaea - differ from bacteria in several ways but have no
peptidoglycan
Common in extreme conditions
2. Halophiles - live at extreme salinities

31. Classification of Prokaryotes
Archaea - differ from bacteria in several ways but have no
peptidoglycan
Common in extreme conditions
3. Methanogens - use CO2 to oxidize H2 - release CH3
- “swamp gas”