1. Bacteria Basics

2. Where are bacteria found?
Most bacteria like a warm, dark, and moist environment, but they are found almost everywhere:
-water -air
-soil -food
-on your skin -inside the body
-on most objects

3. How are bacteria classified? Bacteria are classified by shape:
Spiral-shaped
Rod-shaped
Round

4. How do bacteria reproduce?
Bacteria reproduce by binary fission, which is a type of asexual reproduction.
asexual reproduction- reproduction of a living thing from only one parent
binary fission- the process of one organism dividing into two organisms
Fluorescence Imaging of Bacterial Binary Fission - YouTube
www-raider.stjohns.k12.fl.us/.../ sv16.html

5. Bacteria reproduce more rapidly in warm, dark, and moist conditions.
The time it takes for bacteria to reproduce depends on their environment.
Bacteria reproduce more rapidly in warm, dark, and moist conditions.
Some can reproduce every 20 minutes.
(At that rate, one bacterium could become one million bacteria in six hours.)

6. A key to their survival
Bacteria are able to survive harsh conditions by forming endospores.
Endospore - a thick walled, protective structure that forms inside the cell when conditions are unfavorable for survival
A major cause of food poisoning because it allows the bacteria to withstand boiling, freezing, and extremely dry conditions

7. Endospore (the black section in the middle)

8. How can bacteria be harmful?
The wastes produced by some bacteria spoil food.
Since bacteria reproduce better in warm temperatures, it helps to keep food cold.

9. This can happen in several ways: through the air
some bacteria cause communicable diseases (diseases passed from one organism to another)
This can happen in several ways:
through the air
by touching contaminated clothing, food, silverware, toothbrush, etc.
drinking water that contains bacteria

10. Some Bacterial Illnesses
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Some Bacterial Illnesses
Food poisoning
Lyme disease
Tetanus (Lockjaw)
Tuberculosis
Strep throat

11. Treatments for Bacterial Infections
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Treatments for Bacterial Infections
Antibiotics such as Amoxicillin help to cure bacterial infections
Antibiotic ointments and sprays kill bacteria in cuts and scrapes

12. How can bacteria be helpful?
Some bacteria decompose (break down) dead organisms, which recycles nutrients into the soil for other organisms to use to grow.
E-coli bacteria grow in the stomach
of a cow to break down grass and
hay, and in humans to break down
high fiber foods.
Many are used to make antibiotics.

13. Some bacteria help make insulin to treat diabetes.
Bacteria are used to treat sewage. Organic waste is consumed by the bacteria and is no longer present to produce odors, sludge, pollution, or an unsightly mess.

14. Help produce foods such as: Cheese Apple cider Sauerkraut Pickles

15. Sourdough bread Yogurt Cottage cheese Sour cream Buttermilk

16. How can bacteria be controlled?
1) Canning- the process of sealing food in airtight cans or jars after killing bacteria
2) Pasteurization- process of heating milk to kill harmful bacteria and then cooling it quickly
3) Dehydration- removing water from food
(Bacteria can’t grow when H2O is removed example: uncooked noodles & cold cereal)

17. Antiseptics & 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

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The End