1. Ahh! Germs – Everywhere! Germ = microorganisms (microbes)
*tiny life forms that multiply
Examples: Viruses, Fungi, Bacteria

2. What are bacteria/Why should I care?
You may have over a billion bacteria on the inside and outside of your body right now
Maybe half a million under each fingernail

3. Bacteria – unicellular, prokaryotes
Bacteria like a warm, dark, and moist environment
They are found almost everywhere:
-water -air
-soil -food
-skin -inside the body
-on most objects

4. 7 Major Structures of a Bacteria Cell
Capsule
Cell wall
Ribosomes
Chromosome (nucleoid)
Flagella
Pilli
Cytoplasm

5. 7 Major Structures of a Bacteria Cell
Capsule
keeps the cell from drying out and helps it stick to food or other cells
More likely to cause disease

6. 7 Major Structures of a Bacteria Cell
Flagellum
a whip-like tail that some bacteria have for locomotion

7. Pilli 7 Major Structures of a Bacteria Cell
hollow hair-like structures made of protein
allows bacteria to attach to other cells and exchange genetic material
Pilli-plural
Pillus-singular

8. 7 Major Structures of a Bacteria Cell
Cytoplasm
clear jelly-like material that makes up most of the cell

9. 7 Major Structures of a Bacteria Cell
Ribosomes
cell part where proteins are made

10. 7 Major Structures of a Bacteria Cell
Chromosome
a ring made up of DNA, contains most of bacterium’s genes

11. 7 Major Structures of a Bacteria Cell
Cell wall
Thick outer covering that maintains the overall shape of the bacterial cell
Prevents bursting in hypotonic environment

12. Plasmid
A few genes located in a small circular chromosome (may have one or more plasmids)
The key to resistance…bacteria pass on plasmids to other bacteria, and they typically code for resistance to antibiotics

13. Bacteria come in different shapes and sizes
3 Shapes of Bacteria
Bacteria come in different shapes and sizes
Spiral:
spirillum
rod-shaped: bacillus
Round:
coccus

14. Bacteria Arrangements
Diplo = pairs of cells
Staphylo = grape-like arrangment
Strepto = chain of cells

15. THE SIX KINGDOMS Archaebacteria Eubacteria
Archaebacteria
Eubacteria

16. Archaebacteria Bacteria found in extreme environments 3 Types:
1. methane-producing (swamps, digestive tracts of cows & other mammals)
2. Salt-loving
3. Heat and acid loving (cracks in ocean floor, hot springs)

17. Anaerobic Can live without oxygen – often oxygen would kill them
Ex. Bacteria in swamps

18. Eubacteria Found: Almost everywhere 3 Types: 1. Heterotrophs
Parasites (feed on living organisms)
Saprophytes (feed of dead organisms and waste)
2. Photosynthetic
3. Chemosynthetic

19. Chemosynthesis:
Making energy by breaking down sulfur and nitrogen compounds
(ex. Bacteria convert N2 in the atmosphere into usable form for plants – nitrogen fixation)

20. Bacteria = prokaryote 3 differences between bacteria and animal cell
Bacteria= no nucleus, Animal = nucleus
Bacteria = Flagellum, Animal = no flagellum
Bacteria = cell wall, Animal = no cell wall

21. How can we get rid of bad bacteria?
Antibiotics = chemical that kills bacteria
The first antibiotic: 1929
Penicillin (made from mold)

22. How does an antibiotic work?
Makes holes in cell wall causing the cells to rupture

23. Reproduction of Bacteria
Binary Fission- the process of one organism dividing into two organisms
Fission is a type of asexual reproduction
Asexual reproduction- reproduction of a living thing from only one parent
How?...
The one main (circular) chromosome makes a copy of itself
Then the cell divides into two
www-raider.stjohns.k12.fl.us/.../ sv16.html

24. BINARY FISSION Bacteria dividing Completed Reproduction of Bacteria
Bacteria dividing
Completed

25. Sexual Reproduction = conjugation
Bacteria connect by pilli and transfer part of their chromosome
Like an airport skyport transferring people!

26. Reproduction of Bacteria
The time of reproduction depends on how desirable the conditions are
Bacteria can rapidly reproduce themselves in warm, dark, and moist conditions
Some can reproduce every 20 minutes

27. Binary Fission Bacterial Cell & Nucleiod DNA Ring DNA replication
Cell wall synthesis
Cell separation

28. Bacteria Survival
Endospore-
a thick walled structure that forms inside
the cell
they are the major cause of food poisoning
allows the bacteria to survive for many years
they can withstand boiling, freezing, and extremely dry conditions
it encloses all the nuclear materials
and some cytoplasm

29. Endospore-the black section in the middle
Bacteria Survival
Bacillus subtilis
Endospore-the black section in the middle
highly resistant structures
can withstand radiation, UV light, and boiling at 120oC for 15 minutes.

30. Tetanus Clostridium tetani Produce a powerful nerve toxin
Endospores can exist almost anywhere, if get into a wound they germinate and produce toxin 30

31. 3 ways to control bacteria:
Controlling Bacteria
3 ways to control bacteria:
1) Canning- the process of sealing food in airtight cans or jars after killing bacteria
endospores are killed during this process
2) Pasteurization- process of heating milk to kill harmful bacteria
3) Dehydration- removing water from food
Bacteria can’t grow when H2O is removed
example: uncooked noodles & cold cereal 31 31

32. Botulism Clostridium botulinum
On foods, if foods aren’t canned properly they form an endospore and then germinate in the anaerobic environment of the can
Produce toxins – can cause food poisoning 32

33. Bacteria Survival – Food sources
parasites – bacteria that feed on living things
saprophytes – use dead materials for food (exclusively)
decomposers – get food from breaking down dead matter into simple chemicals
important- because they send minerals and other materials back into the soil so other organisms can use them 33 33

34. some bacteria cause diseases Animals can pass diseases to humans
Harmful Bacteria
some bacteria cause diseases
Animals can pass diseases to humans
Communicable Disease –
Disease passed from one organism to another
This can happen in several ways:
Air
Touching clothing, food, silverware, or toothbrush
Drinking water that contains bacteria 34 34

35. BLUE-GREEN BACTERIA
Autotrophs – make their own food through photosynthesis
larger than most bacterial cells
commonly grow on water and surfaces that stay wet…such as rivers, creeks and dams
Some live in salt water, snow, and acid water of hot springs
food source for animals that live in the water 36 36

36. BLUE-GREEN BACTERIA can be toxic to humans and animals
Blooms- occur when the bacteria multiplies in great numbers and form scum on the top of the water 37

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Harmful Bacteria
Human tooth with accumulation of bacterial plaque (smooth areas) and calcified tartar (rough areas) 38 38

38. Bacteria grow in the stomach of a cow to break down grass and hay
Helpful Bacteria
Decomposers help recycle nutrients into the soil for other organisms to grow
Bacteria grow in the stomach of a cow to break down grass and hay
Most are used to make antibiotics
Some bacteria help make insulin
Used to make industrial chemicals 39 39

39. E.coli on small intestines
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Helpful Bacteria
E.coli on small intestines 40 40

40. Helpful Bacteria Used to treat sewage
Organic waste is consumed by the bacteria, used as nutrients by the bacteria, and is no longer present to produce odors, sludge, pollution, or unsightly mess.
foods like yogurt, cottage & Swiss cheese, sour cream, buttermilk are made from bacteria that grows in milk 41 41

41. The Wanted List
Create flyers for a gallery of “Most Wanted” (beneficial bacteria) and “Least Wanted” (pathogenic bacteria). For each flyer:
provide a mug shot (picture) of the bacterium
name the bacterium (you can add humor, e.g., Sly the Salmonella typhi)
indicate where it might be found (its natural hangout)
specify it’s crime (e.g., poison suspect) or benefit (e.g., yogurt helper) 42

42. Antiseptic vs. Disinfectants
Controlling Bacteria
Antiseptic vs. Disinfectants
Antiseptic- chemicals that kill bacteria on living things
means – “against infection”
Examples: iodine, hydrogen peroxide, alcohol, soap, mouthwash
Disinfectants- stronger chemicals that destroy bacteria on objects or nonliving things 43