1. Bacteria General Characteristics – text ref. p 471-490
found in all environments
Reproduce very quickly-can double every 20 minutes by Binary Fission

3. Prokaryotes Archaea –lack peptidoglycan cell walls
– no nuclear or organelle membranes
- are divided into two domains:
Archaea –lack peptidoglycan cell walls
Eubacteria- cell wall contains complex carbohydrate peptidoglycans that is outside of the cell membrane

4. Kingdom Archaebacteria
Live in very harsh environments. The extremaphiles – can live in very hot, salty or poisonous environments.
Eg: outgassing vents at the oceans floor or the METHANOGENS which release
methane gas.
Example: Thermoplasma

5. Kingdom EUBACTERIA Classification –Appendix E pg 1072
EUBACTERIA –(true bacteria) largest group, most are heterotrophs, some are photosynthetic, some produce disease (pathogenic)
Examples – Escherichia coli,
Streptococcus

6. Shapes – 3 common shapes 1. bacilli (bacillus) – rod shaped
2. cocci (coccus) – spherical
3. spirilli (spirillum) – spiral
4. some clump together:
-streptococci – long chains
-diplococci – pairs or small groups
-staphylococci – clusters of cells

7. Structure of Prokaryotic Cells
use p 472 to draw and label a prokaryotic cell
bacteria cell walls are either Gram + or Gram- depending on how they stain
Gram + have 1 cell wall and turn purple
Gram(-) have 1 cell wall and
a capsule and turn red

8. Motility (movement) - flagella-some whip or pull with flagella
- some spiral or snake forward – spirilli
- some glide on a slime layer they secrete
- some are sessile (don’t move on their own)

9. Nutrition 2 main groups depending on how they feed
1. Autotrophs- “self-feeding” – usually photosynthesis is involved – phototrophic autotrophs eg: cyanobacteria
chemotrophic autotrophs – oxidize inorganic molecules like N,S, and Fe
2. Heterotrophs – must obtain energy from organic material they ingest. Eg: Salmonella a chemotrophic heterotroph
Energy Metabolism- bacteria have 2 ways of gaining energy from their food:
a) respiration-uses oxygen to release energy-obligate aerobes
b) fermentation-occurs without oxygen-obligate anaerobes like Clostridium botulinum
c) faculative anaerobes-don’t require oxygen but can live in it

10. Lifestyles of Bacteria
Bacteria (and all organisms) can be:
a) parasitic-live on other organisms (the host) eg: dental placque
b) symbiotic-live in a close relationship with another organism in a mutually beneficial way eg: Lichens-a fungus & cyanobacteria combined together
c) saprophytic-decomposers-feed on dead organisms- important in food chains to recycle nutrients

11. Reproduction Usually reproduce asexually by Binary Fission
-advantage-double population every 20 min.
-disadvantage-offspring identical DNA to parent

12. Conjugation- a pilli tube connects 2 cells and DNA is exchanged to allow new gene combinations. Not true sexual reproduction because no new cells are made

13. Reproduction
Usually reproduce asexually by Binary Fission
-advantage-double population every 20 min.
-disadvantage-offspring identical DNA to parent
Spore formation - sometimes resistant dormant endospores are made to survive harsh conditions
Conjugation- a pilli tube connects 2 cells and DNA is exchanged to allow new gene combinations. Not true sexual reproduction because no new cells are made

14. The Importance of Bacteria
a) Only 2% of bacteria are pathogens! Pathogenic bacteria harm us by releasing toxins and attacking cells/tissues. Diseases include: TB, bubonic plague, typhoid fever, tetanus, syphilis, cholera, diptheria, listeriosis b) Bacteria are essential members of all ecosystems because: 1. Nitrogen fixing-these bacteria are the only organisms on earth capable of taking nitrogen and “fixing” it in a chemical form (NH3 – ammonia). All organisms need nitrogen to make DNA and amino acids to make proteins. Plants like soy house bacteria (Rhizobium) to fix nitrogen for them.

15. The Importance of Bacteria
b) Bacteria are essential members of all ecosystems because: 1. Nitrogen fixing-these bacteria are the only organisms on earth capable of taking nitrogen and “fixing” it in a chemical form (NH3 – ammonia). All organisms need nitrogen to make DNA and amino acids to make proteins. Plants like soy house bacteria (Rhizobium) to fix nitrogen for them. 2. Primary producers- bacteria form the base of most food chains 3.Decomposers- bacteria help to recycle the chemistry of dead material in all food chains 4. Symbiotic relationships- like digesting cellulose for grazers like cows and termites, or finishing digestion off in our large intestine 5.Release oxygen into the atmosphere-anaerobes 6.Sewage and waste treatment plants

16. Human Uses For Bacteria
1. Foods-cheese, yogurt, alcohol ect. 2. digestion-converting nutrients in our gut 3. drugs-eg: most antibiotics come from bacteria 4. Genetic Recombinant Bacteria-we can splice new genes into bacteria to get them to make things like insulin for us 5. sewage treatment plants 6. environmental clean-up bacteria can detoxify things like oil spills

17. Controlling Bacteria
-these are methods to slow, limit or even stop bacterial growth: 1.sterialization - most bacteria cannot survive boiling water (denatures bacteria proteins) 2.disenfectants - chemicals that kill (lyse) bacteria (alcohol, vinegar, tee tree oil, lemon) (environment which doesn’t support the microbe from growing) 3. food processing – to slow reproductive rates eg: freezing, refrigeration, canning, pickling, salting, dehydrating, sealing in plastic

18. Hand-in ONE worksheet EACH at end of class for marks
Review Activity
There are FOUR stations to read material and answer the questions….
You will travel in your group of 4 to visit all of them
Follow the yellow or the pink route
THERE ARE ONLY FOUR STATIONS
Pink station #1 is exactly the same as the yellow station #1
Hand-in ONE worksheet EACH at end of class for marks