1. Chapter 19: Bacteria
Edwin P. Davis, M.Ed.
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2. Bacteria
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3. Bacteria
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4. Classification of Bacteria
Archaebacteria
The extremists
Oxygen – free environments
Produce methane
Concentrated salt water environments
Great Salt Lake, UT
The Dead Sea, Middle East
Hot, acidic waters of sulfur springs
The Dead Sea, Israel
The Great Salt Lake, UT
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5. Eubacteria The heterotrophs Found everywhere
Need organic molecules as an energy source
Parasites
Absorb nutrients from living organisms
Saprobes
Organisms that feed on dead organisms or organic waste
Help recycle the nutrients contained in decomposing organisms
Saprobe
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6. The photosynthetic autotrophs
Obtain energy from light
Cyanobacteria (cyano, blue-green)
Trap the sun’s energy by photosynthesis using their blue-green pigment
Some are red or yellow
Found in ponds, streams and moist land
Composed of chains of cells
Exception to unicellular rule
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7. The Chemosynthetic autotrophs
Obtain energy from chemosynthetic breakdown of inorganic substances
sulfur or nitrogen compounds
Important in converting nitrogen in the atmosphere to forms readily used by plants
Underwater sea vent
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8. Bacteria
At the center of the cell is usually a single chromosome.  Like the DNA or RNA in animal or human cells, the bacterial chromosome has full capability to replicate itself.  
Bacterial Cell Structure
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9. Bacteria
Unlike higher organisms, the bacteria's chromosome is not protected from the cytoplasm (fluid of the cell) by a nuclear membrane (such as in the nucleus of a protozoan).
Also, bacteria may have extra pieces of DNA (called plasmids), as well as ribosomes (they help the chromosome replicate) in the cytoplasm.
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11. Structure of Bacteria Microscopic, simple, living
Prokaryotic, no true nucleus
Non-membrane bound organelles
Ribosomes smaller
Inherited information held in single circular chromosome
As opposed to paired chromosomes
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12. Eukaryotic & Prokaryotic Cells
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13. Prokaryotes are identified by:
Prokaryotic Cells
Prokaryotes are identified by:
Their shape
Their chemical nature of their cell walls
The way they move
The way they obtain energy
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14. Prokaryotic Cell shape
3 main cell shapes
Bacilli – Rod shape
Cocci – spherical shaped
Spirilla – Spiral & corkscrew
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16. Shapes of Bacteria Shape Spheres coccus Rods bacillus Spiral spirillum
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17. Prokaryotic Cell shape
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18. Bacteria Morphology
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19. Bacterial Cell Arrangement
Diplo – cells are paired
Staphylo – cells are in grape-like clusters
Strepto – cells are in long chains
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20. Bacteria Morphology
 Introduction: Bacteria, fungi and other microorganisms are the main cause of most disease or other unpleasant symptoms. We try to avoid such organisms by staying away from polluted or infected places and by using personal hygiene products such as soaps, detergents and antibacterial agents. Despite all our efforts, bacteria are present almost everywhere, and some bacteria can make us sick. 
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21. Prokaryotic Cells
Cells that lack a membrane-bound nucleus are called prokaryotes (from the Greek meaning before nuclei).
Prokaryotic cells don't have a membrane-bound nucleus and instead of having chromosomal DNA, their genetic information is in a circular loop called a plasmid.
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22. Prokaryotic Cell Walls
2 different cell walls
Gram Positive Cell Wall – thick peptidoglycan walls
Gram Negative Cell Wall – thinner peptidoglycan walls
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23. Bacillus Anthracis Cerebrospinal fluid
Prokaryotic cell wall
Gram Positive Stain
Bacillus Anthracis Cerebrospinal fluid
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24. Prokaryotic Cells
Bacteria perform many important functions on earth. They serve as decomposers, agents of fermentation, and play an important role in our own digestive system.
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25. Protection from osmotic pressure
Cell walls
Made of long chains of sugar linked by short chain amino acids
Prevent osmotic rupture
Most bacteria live in hypotonic environment
Water always enter in
Cell wall prevents bursting of cell
If ruptured, cell dies
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26. Examples of Prokaryotic Cells
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27. Eukaryotic Cells
Eukaryotic cells (from the Greek meaning truly nuclear) comprise all of the life kingdoms except Monera. They can be easily distinguished through a membrane-bound nucleus.
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28. Eukaryotic Cell Examples
Picture of a Bread Yeast - (from the fungi kingdom)
Picture of a Centric Diatom (from the Protista kingdom)
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29. Eukaryotic Cell Examples
Human Red Blood Cells, Platelets, and T-lymphocytes (from the Animalia kingdom
Human Liver Cell (from the Animalia kingdom)
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30. Prokaryotic Vs. Eukaryotic Cells
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31. Penicillin – Bacterial Killer?
Interferes with the enzyme that links the sugar chains in the cell wall
Bacteria growing in penicillin develop holes in their cell walls
Water enters, bacteria dies
Not effective in viruses and animals
Neither has cell walls
Nontoxic to plants
Plant cell wall is different structure from bacterial cell wall
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32. Miracle Cure – The Story of Penicillin
Discovered by Alexander Fleming in 1928
Produced from an airborne mold, Penicillium notatum
World’s first antibiotic
Purified in 1940
Kills bacteria and inhibit their growth
Killed his dish of staphylococcus
Streptomycin, second leading antibiotic, discovered in 1943
Penicillium notatum
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33. Ecology and Adaptation
Diversity of metabolism
Obligate aerobes
Bacteria that require oxygen for cellular respiration
Mycobacterium tuberculosis
Person with TB
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34. Post primary Tuberculosis (“Reactivation TB”)
Most cases in adults occur as reactivation of a primary focus of infection acquired in childhood Limited mainly to the apical and posterior segments of the upper lobes and the superior segments of the lower lobe
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35. Tuberculosis
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36. Obligate anaerobes Cannot use oxygen Are killed by it
You cannot get syphilis from toilet seat.
Syphilis - causing bacteria
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37. Complex biochemical pathways Green sulfur bacteria
Use hydrogen sulfide instead of water for photosynthesis
Produce sulfur instead of oxygen
Grow in anaerobic environments like lake sediments
Green sulfur bacteria
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38. Adaptations for survival
Endospores
Have hard outer covering
Resist drying out, boiling, freezing, many chemicals
Bacteria is in slow metabolism, does not reproduce
When in favorable conditions, germinates and gives rise to bacterial cell
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39. Clostridium botulinum
Obligate anaerobes
Form endospores
Produces an extremely powerful toxin (poison)
Don’t die when exposed to oxygen
Can find their way into canned food
If not properly sterilized
endospores germinate
bacteria grow
produce their deadly toxin
Causes botulism
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40. Clostridium tetani Produces powerful nerve toxin
Causes often-fatal disease, tetanus
Endospores are found in every surface
Can enter wound easily, germinate and release toxin
Immunization is prevention
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41. Anthrax
Anthrax is primarily a disease of animals, however, it can occasionally be transmitted to humans. The disease is caused by Bacillus antracis, a Gram positive, rod shaped, and endospore forming microorganism.
Endospore formation is necessary in times of unfavorable living conditions (e.g. low water availability, extremely high temperatures, etc.).
The bacteria remains dormant until environmental conditions becomes suitable for living
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42. ANTHRAX
Transmission to humans can occur by direct contact of the skin with the endospores of B. antracis, via the respiratory tract through inhalation of spores, and via the gastrointestinal tract through the ingestion of spores.
If disease is inhaled
Mild Fever, Malaise
Fatigue, Coughing
Feeling of pressure on chest
If disease contract through skin
a boil develops that eventually forms a black center
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43. Bacteria
Reproduction
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44. 1. Binary Fission Asexual reproduction Copies its single chromosome
Copies attach to cell’s plasma membrane
Cell divides into two as partition forms between two new cells
Each cell has one copy of chromosome
Just like mitosis, but the whole organism is copied
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45. Binary fission
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46. 2. Conjugation Sexual reproduction
One bacterium transfers all or part of its chromosome to another
Pilus (pili)
Bridge-like structure
Connects two cells
Used to transfer genetic material
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47. Conjugation
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48. Bacteria
Economic Importance
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49. Bacteria on legume roots
Nitrogen fixation
Convert N2 gas into ammonia (NH3)
Convert ammonia (NH3) to nitrite (NO2-) and nitrate (NO3-)
Some form symbiotic relationship with peas, peanuts, and soybeans
Helps them grow better when nitrogen is lacking
When they are harvested, remaining roots add nitrogen to soil
Bacteria on legume roots
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50. Recycling of nutrients
Cyanobacteria
Replenish supply of oxygen in atmosphere
Autotrophic bacteria
Convert carbon dioxide in the air to the organic compounds that are passed to consumers in food chains and webs
All life depend on bacteria
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51. Food and medicines
Used to produce vinegar, yogurt, butter, cheese, pickles, sauerkraut
Used to produce antibiotics to kill other bacteria
Streptomycin
Erythromycin
Chloromycetin
Kanamycin
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52. Bacteria cause disease
Half of human disease is caused by bacteria
Tuberculosis
Scarlet fever
Rocky Mountain spotted fever
Bacterial pneumonia
Syphilis
Tetanus
Botulism
Gonorrhea
Ear infections
Strep throat
Chlamydia
Boils
Staph infections
Diphtheria
Lyme disease
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