Bacteria_Demo.ppt>>Bacteria lesson

1. What is the link between this things?

2. The link between these things is…

3. Mr : Osama Hasn

4. Lesson objectives :
1- List the main features of bacteria.
2- Identify the function of bacteria cell parts.
3- Clarify the Mechanism or methods of survival
of bacteria.
Bacteria

5. Classification :
Prokaryotes cell , single celled
Classified in 2 Domains and 2 Kingdom :
1- Archaea (Archaea Bacteria)
–Archaea bacteria Kingdom (ancient)
–found in Harsh habitats as (swamps, hot
sulfur springs, Great Salt Lake, deep ocean
vents.
2- Bacteria (Eubacteria)
–Eubacteria Kingdom
–found in almost any habitat except harsh
habitat

6. What are three features of a bacteria?
1- Bacteria are microscopic.
2- Bacteria are (single-celled) organisms.
3- Bacteria are prokaryotic organisms.
Bacteria

7. Kingdom of Eubacteria :
ex :
streptococcus Escherichia coli anabaena
Bacteria

8. Choose the correct answer :
Bacteria can be seen by naked eye ( )
Bacteria are (Multi-celled) organism as Human ( )
Bacteria can be found at human skin ( )
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9. Bacteria Cell Structure :
• capsule
• cell wall
• Plasma Membrane
• nucleic acid (nucleoid)
• flagella
• pili
• ribosomes
• plasmid
Bacteria

10. Bacteria Cell Structure :
• capsule: keep the bacterium from drying out
and to protect it from phagocytosis.
• cell wall : gives the cell its shape and,
protecting it from the environment .
• plasma membrane : regulate the flow of
materials in and out of the cell.
• nucleic acid : responsible for replication.
Bacteria

11. Bacteria Cell Structure :
• Flagella : help the bacterium to move.
• Pili : assist the bacteria in attaching to other
cells and surface.
• Ribosomes : They translate the genetic code
to proteins .
Bacteria

12. More Cell structure :
• endospore
– tough protein coat formed inside bacteria cell; used
to survive in harsh conditions.
Bacteria

13. bacteria are classified according to:
• shape
• arrangement
• staining properties
Bacteria

14. Classifying Bacteria
bacillus (rod-shaped)
coccus (spherical-shaped)
spirillum (spiral-shaped)
Bacteria

15. Classifying Bacteria
arrangement
• pairs
– diplo…
• clusters
– staphlo…
• chains
– strepto…
Bacteria

16. Classifying Bacteria
arrangement
Bacteria

17. Classifying Bacteria
staining properties
• gram stain negative
–thin layer of peptidoglycan
–stains pink
• gram stain positive
–thick layer of peptidoglycan
–stains purple
Bacteria

18. Life processes
nutrition
• heterotrophs
–parasitic
• ex: staphylococcus aureus
–saprophytic
Bacteria

19. Life processes
nutrition
• photosynthetic autotrophs
–energy from sunlight
–ex: anabaena
Bacteria

20. Life processes
nutrition
• chemosynthetic autotrophs
–energy from chemicals
–ex: Nitrobacteria
Bacteria

21. Life processes
respiration
• obligate aerobes
–require O2 to live
–ex: tuberculosis
• obligate anaerobes
–can not live in presence of O2
–ex: botulism
• facultative anaerobes
–lives with or without O2
–ex: E. Coli
Bacteria

22. Life processes
reproduction
• binary fission
–split in two (asexual reproduction)
Bacteria

23. Life processes
reproduction
• conjugation
– transfer of genetic
material to an
acceptor bacterium
– sexual
reproduction
Bacteria

24. Life processes
reproduction
• spores
–buds form and produce new cells
–spores can survive a long time before
“hatching”
Anthrax spores
Bacteria

25. Advantages of bacteria
• human intestine
• food production-
–milk, buttermilk, yogurt, sour cream, cheese
• ecology
–decomposers
–nitrogen fixation
• producers
Bacteria

26. Disadvantages of bacteria
diseases
Bacteria

27. Disadvantages of bacteria
diseases
• most bacteria affect host be producing toxins
• endotoxin
–toxic substance bound to cell wall
• exotoxin
–secreted substance toxic
treatment
• antibiotics
–medication used to help kill or assist immune
system in destruction of bacteria
Bacteria