1. Bacteria

2. Key Characteristics What type of cell are bacteria?
Prokaryotic – they have no nucleus!
How many cells is each bacterium made of?
One! Bacteria are unicellular
Range in size from 1 – 5 micrometers
2000 – can fit the diameter of a penny!!!
Do they move?
Some do and some don’t
How do they reproduce?
Some are sexual, while others are asexual
Do they have a cell wall?
Yes

3. Two Groups of Bacteria Eubacteria Archaebacteria
Live everywhere – land, water, human body
Example – E. coli – human intestines
Surrounded by a cell wall made up of peptidoglycan
Archaebacteria
Lack peptidoglycan in cell wall
DNA sequences are more like eukaryotes than eubacteria  thought to be ancestral to eukaryotes
Most live in extremely harsh environments

4. Identifying Bacteria Shapes Groupings Cocci – spherical or round
Bacilli – rod
Spirrila – spiral
Groupings
“Diplo-” = paired
“Strepto-” = chains
“Staphylo-” = clusters

5. What shape is this?
Diplobacilli

6. What shapes can you find in this photo?

7. How do they move?
Some bacteria have flagella, which is a whip-like structure that acts as a tail.
Some move by lash, snake, or spiral movement
Some excrete a slime-like material that helps the bacterium cell glide.

8. Notice their tails?

9. Metabolic Diversity - Heterotrophs
Chemoheterotrophs:
Energy source – organic compounds
Carbon source – organic compounds
Ex = most animals and bacteria
Photoheterotrophs:
Energy source – sunlight

10. Metabolic Diversity - Autotrophs
Photoautotrophs:
Energy source – sunlight
Carbon source – carbon dioxide
Ex = all photosynthetic organisms
Chemoautotrophs:
Energy source – inorganic chemicals (hydrogen sulfide, iron, sulfur)
Ex = chemosynthetic organisms

11. Where can you find chemosynthetic bacteria?

12. Releasing Energy – Respiration
Obligate aerobes –
organisms that require a constant supply of oxygen in order to live
Mycobacterium tuberculosis
Obligate anaerobes –
organisms that must live in the absence of oxygen
Clostridium botulinum – Botulism – food poisoning
Facultative anaerobes –
organisms that can survive with or without oxygen  perform both cellular respiration and fermentation which allows them to live anywhere
E. coli

13. Mycobacterium tuberculosis

14. Clostridium botulinum
Did you know that this is the same stuff they put in Botox injections?

15. Escherichia coli

16. Growth and Reproduction
Binary fission –
Type of asexual reproduction in which an organism replicates its DNA and divides in half, producing two identical daughter cells
Conjugation –
Form of sexual reproduction in which there is an exchange of genetic information
Spore formation (endospores) –
When growth conditions are unfavorable, bacteria form spores, which can remain dormant for months or years while waiting for more favorable growth conditions

17. Binary Fission

18. Conjugation

19. Importance of Bacteria
Decomposers –
Help ecosystems recycle nutrients
Break down dead tissue
Help in sewage treatment
Nitrogen fixers –
Convert nitrogen gas into a form of nitrogen that plants can use  nitrogen fixation
Human uses –
Production of many foods and drinks
Help clean up oil spills – can digest petroleum
E. coli – lives in human large intestines – produces vitamins that body cant produce on own

20. The Amazing World Of Gumball