Transcript Chapter 18 Archaebacteria and Eubacteria

Chapter 18
Archaebacteria & Eubacteria
Prokaryotes
• Unicellular
• No membrane-bound organelles
• Found all over world
Special Features
• Pilus - hairlike protrusion
– sticks to surfaces
– bridge for sexual reproduction
• Flagellum - long, whiplike protrusion, for
moving
• Capsule - sticky layers around cell wall
• Toxin - a powerful poison
• Endospore - DNA and cytoplasm bundle
– resists harsh environments
– viable for up to thousands of years
Bacteria
Flagella
Endospores I
Endospores II
Identification of Bacteria:
• Growth patterns
– Diplo-pairs , Staphylo- clusters, Strepto- chains
• Shape
– Cocci (Spheres), Bacilli (Rods), Spirilli (Spiral)
– Naming = growth pattern + shape
• Gram stain
– Cell wall
– Gram+Thick wall= Purple Stain, gram-Thin wall = Pink Stain
Gram Stain
Growth Patterns
Reproduction
Asexual
• Binary Fission
• Rapid
Sexual
• Conjugation
• Pili
Asexual Reproduction
Sexual Reproduction
Metabolism
(Cellular Respiration)
Obligate
Aerobes
Obligate
Anaerobes
Need Oxygen for
respiration
Die from Oxygen
Archaebacteria
O2-free Archaebacteria
• Produce methane gas
• Live in
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Marshes
Lakes sediments
Digestive tracts
Sewage disposal plants
Salt Archaebacteria
• Live in
– Utah’s Great Salt Lake
– Middle East’s Dead Sea
Heat, Acidic Archaebacteria
• Anaerobic
• Live in
– Sulfur springs
– Pacific Ocean’s floor cracks
Eubacteria
• “True” bacteria
• Live in more habitable environments
Heterotrophs
Feed on organic
molecules
Are Parasites and
Saprophytes
Photosynthetic
Autotrophs
Need sunlight to
make food
Example:
Cyanobacteria
Chemosynthetic
Autotrophs
Need sulfur &
nitrogen to make
food
Perform
Chemosynthesis
Cyanobacteria =
Photosynthetic Autotroph
Antibiotics
• Sir Alexander Fleming
– In 1928 he discovered
Penicillium notatum
Beneficial Bacteria
• In plants
• Nitrogen fixation
– DNA, RNA, ATP
Beneficial Bacteria
• Decomposing
– Breakdown dead organisms and wastes
– Return nutrients
– Form bottom of food chain
Beneficial Bacteria
• Produce antibiotics
• Make food:
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Cheese
Pickles
Yogurt
Vinegar
Sauerkraut
Disease-causing Bacteria
• Carried in
– Air
– Food
– Water
• Cause 1/2 of all human disease
• Rare
Bacteria Pathogens “Local” infections - disease changes
with area of body
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Streptococcus causes tooth decay - mouth
Strep throat - pharynx/larynx
Bronchitis - Bronchi/bronchioles
Pneumonia - lungs/alveoli
Pneumococcus causes ear infections - ear
Pneumonia - lungs/alveoli
Osteocytis- bone
Air-Born
Pneumonia
Streptococci