High school biology lesson about bacteria. Covers morphology,

1. Unit 7: The Protists of Curriculum

2. Quick Quiz!!!! (that is a
link… don’t write it down)

3. Vector
A vector is a
piece of DNA
inserted into a
plasmid.
A plasmid is a
circular strand of
DNA within a
bacteria cell.

4. Conjugation
Conjugation gives
genetic variety to
bacterial cells, usually
a resistance to
antibacterial agents.
Conjugation: form of
reproduction by
bacterial cells

5. Recall: Prokaryotes
Single-celled
organisms that
do not have a
membrane
bound nucleus
or organelle.
2 Types
Archaea
Bacteria

6. Archaea

7. Bacteria

8. Archaea
Extremophiles (exist in extreme
environments)
Methanogens: convert hydrogen gas (H2)
to carbon dioxide (CO2); anaerobic
Halophiles (“salt loving”): live in very high
salt concentrations
Thermoacidophiles: live in very high
temperature and very acidic environments:
volcanic and hydrothermal vents.

9. Bacteria: Shapes
1. bacilli: rod shaped
2. Cocci: round/sphere
shaped
3. Spirilla: Spiral
shaped
Variations:
1. Streptococci: chains
of cocci
2. Staphylococci:
clusters of cocci

10. Bacilli

11. Cocci

12. Spirilla

13. Streptococci

14. Staphylococci

15. Lets Draw
1. Bacilli
2. Cocci
3. Spirilla

16. Lets Draw
4. Streptococci
5. Staphylococci

17. Gram stains
Categories based on chemical
components of cell walls
2 types:
Gram negative: appear reddish pink under
microscope; have a cell wall and small
amount of peptidoglycan
Gram positive: appear purple under
microscope; have simple cell walls and
more peptidoglycan

18. Gram Stain

19. Biology of Bacteria
Cell walls contain peptidoglycan- a
protein also found in cell walls of plants
Cell membranes: selective barrier to
external environment
DNA: not bound by nucleus; some exists in
plasmids: small circular loops of double
stranded DNA

20. Biology of Bacteria

21. Biology of Bacteria
Capsules: outer covering of
polysaccharides; protect the cell from
drying or harsh chemicals
Pilli: short, hairlike proteins on surface of
bacteria; help bacteria adhere to surfaces
and each other; also used for conjugation

22. Capsules

23. Pili

24. Biology of Bacteria
Endospores: dormant forms of bacterial
cells; not reproductive; able to withstand
harsh environmental conditions
Flagella: allow bacterial movement
Taxis: move toward or away from a
stimulus
What do you think chemotaxis is?

25. Endospore

26. Endospore

27. Flagellum

28. Bacteria Monster

29. Bacteria Monster
Use the table on the next slide to draw a
bacteria “monster.”
1. Shake up your alleles (pennies—
stickers are dominant).
2. Drop alleles on the desk.
3. Decide if your “monster” will have or
dominant or recessive phenotype.
4. Draw the phenotype for each category
to create one “monster.”

30. Bacteria Monster
Trait: Dominant: Recessive
Shape Cocci (round) Baccili (rod)
Configuration Single Double
Color: Red Blue
Flagellum Double Single
Capsule Present Absent
Pilli Absent Present

31. Example:

32. Your turn!
• Work with your partner
• You will make 3 “monsters”
• Draw them on the back of today’s
notes

33. Metabolism
Heterotrophs: consume other organisms
Autotrophs: make own food
Phototrophs: make food from photons
(sunlight)
Chemotrophs: make food from chemicals
in the environment

34. Habitats
Obligate anaerobes: cannot live where
oxygen is present
Facultative anaerobes: can live with or
without oxygen
Obligate aerobes: need oxygen to live

35. Reproduction
Most bacterial cells reproduce through an
asexual process known as binary fission.

36. Reproduction
Transformation: takes in DNA from its
outside environment
Conjugation: two bacteria bind together
and one cell transfers DNA to the other
Transduction: virus copies itself within a
host also transferring DNA from bacteria