1. Diversity of Living Things
Bacteria

2. Classification of Bacteria
Bacteria and prokaryotes are classified based on:
1) Their shape and colony groupings.

3. Classification of Bacteria
Bacteria and prokaryotes are classified based on:
2) The structure of their cell wall.
Bacterial Peptidoglycan Cell Wall
Cell Membrane

4. Classification of Bacteria
Bacteria and prokaryotes are classified based on:
3) Their sources of food or metabolism.

5. Bacterial Shapes
All bacteria are unicellular, however, some cells stick together in colonies.
- Cocci – sphere shaped bacteria
- Bacillus – rod shaped bacteria
- Spirrillium – spiral shaped bacteria

6. Colony Shapes
All bacteria are unicellular, however, some cells stick together in colonies.
- Diplo - cells arranged in pairs
- Staphylo - cells arranged in clusters resembling grapes
- Strepto - cells arranged in a chain

7. Cell Wall Structure
- A thin layer of cell wall protein makes Gram negative bacteria stain pink.
- A thick later of cell wall protein makes Gram positive bacteria stain purple.

8. Gram +ve
Gram -ve
Cell Wall Structure

9. Food and Metabolism - The four groups are:
1) Photoautotrophs - use light energy for photosynthesis and get carbon from CO2.
CO2

10. Food and Metabolism - The four groups are:
2) Photoheterotrophs - consume other organisms to get carbon and use light energy

11. Food and Metabolism - The four groups are:
3) Chemoautotrophs - get energy by breaking bonds in inorganic molecules like ammonia (NH3) and hydrogen sulphide (H2S).

12. Food and Metabolism - The four groups are:
4) Chemoheterotrophs - get both their carbon and energy from eating organic molecules like sugar that are made of carbon (C) and hydrogen (H).

13. Movement Flagellum - A whip-like tail for motion.
Cilia - Tiny hairs on the surface of the cell beat and move cell.

14. Reproduction - Binary Fission
Bacteria usually reproduce asexually by using binary fission.
The bacterial cell copies the genetic infomratyion in the loop of DNA, then splits into two identical daughter cells.

15. Reproduction - Binary Fission

16. Reproduction - Conjugation
- Bacteria can share DNA sexually using conjugation.
- A bacterial plasmid DNA loop containing genetic information can be transferred from one bacterial cell to another.
- DNA from the plasmid loop can integrate into the chromosome DNA loop.

17. Reproduction - Conjugation
Step 1
Step 2
Step 3

18. Spore Formation - Endospores
- A spore is a type of dormant cell.
- Exhibits no signs of life.
- Highly resistant to environmental stresses such as:
- High temperatures
- Irradiation
- Strong acids
- Disinfectants

19. Spore Formation - Endospores

20. Beneficial Bacteria
Not all bacteria are harmful to humans, their usefulness far outweights the damage they do.

21. Beneficial Bacteria
Bacteria help in:
- Decomposing dead things.

22. Beneficial Bacteria Bacteria help in:
- Helping organisms (including us) digest food.

23. Beneficial Bacteria Bacteria help in:
- Helping clean up toxins that seep into soil and water.