1. Unit 5: Classification / Microorganisms Kingdom Archaebacteria, & Kingdom Eubacteria

2. Kingdom Archaebacteria: Ancient Bacteria a.k.a. Domain Archaea a.k.a. Domain Archaea Prokaryotes Prokaryotes Live in extreme conditions Live in extreme conditions NO PEPTIDOGLYCAN  thick outer covering of archaebacteria NO PEPTIDOGLYCAN  thick outer covering of archaebacteria

3. Kingdom Archaebacteria: Ancient Bacteria 3 types: 3 types: 1) Methanogens – produce methane gas 2) Halophiles – “salt-loving” 3) Thermophiles – means “heat-loving”

4. Kingdom Eubacteria: Pathogenic Bacteria A.k.a. Domain Bacteria A.k.a. Domain Bacteria Prokaryotes Prokaryotes Live almost anywhere (very diverse) Live almost anywhere (very diverse) Cell walls w/ peptidoglycan Cell walls w/ peptidoglycan

5. Kingdom Eubacteria: Pathogenic Bacteria Examples: Examples: –Streptococcus –Staphylococcus aureus –Bacillus pneumonae –Clostridium botulinum

6. Prokaryote Classification – 3 Main Ways Prokaryotes are classified based on SHAPE, CELL WALLS, and how they obtain/release ENERGY. Prokaryotes are classified based on SHAPE, CELL WALLS, and how they obtain/release ENERGY. 1) Shapes –Cocci: round (letter C) –Bacilli: rod-shaped (letter A) –Spirilla: spiral-shaped (letter B)

7. Figure 27.3 The most common shapes of prokaryotes

8. Prokaryote Classification 2) Cell Walls –How much peptidoglycan?

9. Gram staining Adds dye to bacteria  the way it stains is an indicator of the type of bacterium (its structure) Adds dye to bacteria  the way it stains is an indicator of the type of bacterium (its structure) Gram positive = stains PURPLE – has simple, thick cell wall made of polysaccharides Gram positive = stains PURPLE – has simple, thick cell wall made of polysaccharides Gram negative: stains PINK – has a protective outer cell membrane; less peptidoglycan in cell walls; structurally more complex (contain lipopolysaccharides that are often toxic to host) Gram negative: stains PINK – has a protective outer cell membrane; less peptidoglycan in cell walls; structurally more complex (contain lipopolysaccharides that are often toxic to host) *negatives are more resistant to antibiotics

10. 3) Energy Obtained (4 ways) 1) Photoautotroph – uses light energy to produce own food 2) Chemoautotroph – uses inorganic molecules (chemicals) to produce own food 3) Photoheterotroph – needs sunlight to obtain food; cannot produce their own food 4) Chemoheterotroph – uses products of chemical reactions to obtain food; cannot produce their own food.

11. 3) Energy Releasing (3 Ways) Prokaryotes can either be… Prokaryotes can either be… 1)Obligate Aerobes – requires oxygen 2)Obligate Anaerobes – requires NO oxygen (Ex: Clostridium botulinum = botulism & BOTOX) 3)Facultative Anaerobes – can function in the presence of oxygen

12. Movement Have Flagella Have Flagella Lash/Spiral forward Lash/Spiral forward Glide using secretions Glide using secretions Not Move  sessile Not Move  sessile

13. Bacterial Reproduction Grow and divide VERY rapidly  Exponential growth (J curve) Grow and divide VERY rapidly  Exponential growth (J curve) Asexually by Binary Fission (Budding) - a method of reproduction in which a prokaryote replicates its DNA and divides in half producing 2 identical “daughter cells” Asexually by Binary Fission (Budding) - a method of reproduction in which a prokaryote replicates its DNA and divides in half producing 2 identical “daughter cells”

15. Bacterial Reproduction Sexually by Conjugation - the transferring of genetic information from one prokaryote to another, with pilli Sexually by Conjugation - the transferring of genetic information from one prokaryote to another, with pilli

16. Bacterial Reproduction In unfavorable condition, bacteria can form Endospores - the process of producing a thick internal wall that allows the prokaryote to remain dormant for long periods of time while conditions are unfavorable for reproduction In unfavorable condition, bacteria can form Endospores - the process of producing a thick internal wall that allows the prokaryote to remain dormant for long periods of time while conditions are unfavorable for reproduction

17. BACTERIA CAN BE GOOD & BAD!!!

18. Bacteria in Nature Bacteria are vital to maintaining the living world: Bacteria are vital to maintaining the living world: –Some are producers that capture energy by photosynthesis –Live in our digestive tracts, and break down the food we need to survive –Live on our skin and eat dead skin cells & other harmful bacteria trying to invade us. As decomposers, bacteria help the ecosystem recycle nutrients As decomposers, bacteria help the ecosystem recycle nutrients –The bacteria breaks down the dead matter into simpler substances As recyclers, bacterial also perform critical steps in sewage treatment As recyclers, bacterial also perform critical steps in sewage treatment –Bacteria break down complex compounds in the sewage into simpler ones

19. Bacteria as Nitrogen Fixers Plants and animals depend on bacteria for nitrogen Plants and animals depend on bacteria for nitrogen –Although the Earth’s atmosphere is approximately 80% nitrogen gas (N 2 ), plants cannot use that nitrogen directly –The process of converting N 2 to a form of nitrogen that plants can use (NH 3 ) is called nitrogen fixation »Certain bacteria are the only organisms that can fix nitrogen in this way

20. Nitrogen Fixation Many plants have a symbiotic relationship with nitrogen fixing bacteria Many plants have a symbiotic relationship with nitrogen fixing bacteria –Soybeans and other legumes host the bacterium Rhizobium »Rhizobium grows in nodules that form on the roots of the plant »The plant provides a source of nutrients for Rhizobium, which converts nitrogen in the air into ammonia, which helps the plant

21. Bacteria and Disease Bacteria are everywhere in nature, but only a few cause disease Bacteria are everywhere in nature, but only a few cause disease –Bacteria that cause disease are called pathogens Bacteria can cause disease in one of two ways: Bacteria can cause disease in one of two ways: –By damaging the tissues of infected organisms as they break them down for food –By releasing toxins that harm the body of the organism

22. Common Diseases Caused by Bacteria DISEASEPATHOGENPREVENTION Tooth decay Streptococcus mutans Regular dental hygene Lyme disease Borrelia burgdorferi Protection from tick bites Tetanus Clostridium tetani Current tetanus vaccination Tuberculosis Mycobacterium tuberculosis Vaccination Salmonella Salmonella enteritidis Proper handling of food Pneumonia Streptococcus pneumoniae Maintaining good health Cholera Vibrio cholerae Clean water supplies

23. Antibiotics vs. Antiseptics Antibiotics – compounds that block the growth & reproduction of bacteria internally Antibiotics – compounds that block the growth & reproduction of bacteria internally –introduced INTO body as injection or –ONTO site of infection as surface medication »EX: Penicillin

24. Antiseptics – Kill bacteria on OUTSIDE of body or on membranes that line areas leading to inside (ex. Mouth) Antiseptics – Kill bacteria on OUTSIDE of body or on membranes that line areas leading to inside (ex. Mouth) Ex. AlcoholNeosporin ListerineAntibacterial soap Iodine Hydrogen Peroxide Disinfectants – act as surface antiseptics for non-living surfaces before bacteria even get to body Disinfectants – act as surface antiseptics for non-living surfaces before bacteria even get to body Ex. Clorox LysolAmmonia

25. Human Uses of Bacteria Bacteria are used in the production of a variety of food : Bacteria are used in the production of a variety of food : –Cheese, yogurt, wine, buttermilk, etc. Bacteria are used in industry : Bacteria are used in industry : –Cleaning up oil spills, removal of wastes from water, synthesis of drugs

26. Controlling Bacteria Sterilization: destroys bacteria by subjecting them either to great heat or to chemical action Sterilization: destroys bacteria by subjecting them either to great heat or to chemical action Refrigeration: causes bacteria to grow slowly Refrigeration: causes bacteria to grow slowly Preservatives: canning prevents bacteria from spoiling shelf foods Preservatives: canning prevents bacteria from spoiling shelf foods Chemical Treatment: chemicals (such as salts) can prevent the growth of bacteria in food Chemical Treatment: chemicals (such as salts) can prevent the growth of bacteria in food

27. Epidemiology The study of public health or the occurrence, transmission, avoidance, & cure of disease. The study of public health or the occurrence, transmission, avoidance, & cure of disease. Focus on the population  changes, rate of incidence of disease, etc. Focus on the population  changes, rate of incidence of disease, etc.

28. Key terms of Epidemiology Disease Prevalence : fraction of the population that currently has the disease. Disease Prevalence : fraction of the population that currently has the disease. Sporadic disease : occurs only occasionally in a population; prevalence = 0 (ex: Typhoid Fever, Bacterial Meningitis). Sporadic disease : occurs only occasionally in a population; prevalence = 0 (ex: Typhoid Fever, Bacterial Meningitis). Endemic : disease that is always present in a population at the same level; prevalence is never zero (ex: Chicken Pox) Endemic : disease that is always present in a population at the same level; prevalence is never zero (ex: Chicken Pox) Epidemic : disease that many people acquire over a short period of time (ex: Cholera, Small Pox, etc.) Epidemic : disease that many people acquire over a short period of time (ex: Cholera, Small Pox, etc.) Pandemic : disease that has a high incidence world-wide (Ex: Influenza, AIDS, etc.) Pandemic : disease that has a high incidence world-wide (Ex: Influenza, AIDS, etc.)