1. BACTERIA

2. STRUCTURE
Do not have a nucleus FLAGELLUM: A tail that rotates for movement GENETIC MATERIAL (DNA): Found free floating in the cytoplasm

3. BACTERIUM STRUCTURE

4. Classifying bacteria Bacteria can be classified based on:
cell wall type
Shape
Arrangement
Respiration (aerobic vs. anaerobic)
Ability to create own food

5. Thermophiles – live in hot environments such as hot springs (temperatures over 45°C)
Methanogens – grow on carbon dioxide and hydrogen gas to produce methane – exist in volcanic deep sea vents and mammals’ intestines
Halophiles – live in saline (salt) environments (salt flats)

6. Bacteria reproduce asexually

8. HELPFUL BACTERIA Bacteria are used for: Decay – decompose dead matter
Fermentation – small intestine (helps digestion)
Creation of foods – vinegar, cheese, yoghurt
Nitrogen Fixing Bacteria – create nitrates needed for soil and found in roots of legumes

9. Harmful bacteria Bacteria can cause infections:
Pathogen – disease causing agent (bacteria/virus)
Create toxins  cause inflammation  death
EXAMPLES: Tuberculosis, Typhoid, Diptheria

10. Harmful BACTERIA Streptococcus – seen in strep throat, pneumonia, etc.
Helicobacter pylori – seen in stomach ulcers
Streptococcus mutans – one of the bacteria that cause cavities
Myobacterium tuberculosis – bacteria causing tuberculosis
Vibrio cholerae – bacteria that causes cholera

11. DEVELOPING AN INFECTION
Entrance – through opening
Attach to specific host – via proteins (antigens)
Survive host defences (immune response)
Cause disease – produce toxins
Exit Host – release through urine, feces, sneezing, coughing

12. HOMEWORK: Read p. 224-231 Answer Q 1,3,4 Answer p. 231 Q 1, 4

13. Fighting Disease

14. DISEASE PREVENTION Practice good hygiene (wash hands)
Practice a healthy lifestyle:
Eat well
Stay active
Protect yourself (ie. Sunscreen)

15. THREE LINES OF DEFENcE
There are 3 lines of defence offered by the immune system
External Defence
Lymphatic System
Antibody Formation

16. External Defence Human Skin – protective barrier
Respiratory Tract has cilia and mucus that will trap bacteria
In eyes, bacteria are destroyed by enzymes in tears

17. Lymphatic System
As microorganisms are collected in the lymphatic system they are destroyed by specialized white blood cells
Macrophage – WBC that eats harmful bacteria
Pus – dead WBC and bacteria

18. Antibody Formation
ANTIBODY: proteins that inactivate foreign substances by attaching to its surface
Each antibody is specific
We can only create antibodies to diseases that we have previously been exposed to
ANIMATION: Immune System Response

19. immunity the production of antibodies to destroy a pathogen
Active Immunity
body produces own antibodies  lifelong
through vaccines
Passive Immunity
Antibodies are injected in blood
Babies get antibodies from their mothers

20. antibiotics kill bacteria ONLY Before prescribing antibiotics:
Doctor will get a sample/sputum
test to ensure it is a bacterial infection (not viral)
Take antibiotics until it is finished

21. Overuse of antibiotics
Can create “super-bugs”  antibiotic resistant bacteria
Infections are difficult to treat
long-lasting illnesses  death
Ex: MRSA – drug resistant bacteria (hospitals)

22. Vaccines Weakened version of bacteria or virus
increase active immunity (body’s own antibodies)
Once pathogenic bacteria and virus enters the body, antibodies recognize it, attach to it and destroy it before it causes damage to our bodies

23. Getting the flu vaccine
Annual vaccine that protects against flu virus that mutates every year
Will cause active immunity against 3-4 flu viruses
No side effects

24. HOMEWORK: Answer p. 231 Q 5, 7, 8, 9