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PART I
Chapter 18
Archaebacteria & Eubacteria
Phylogeny
Characteristics
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First living evidence on earth
Unicellular
Prokaryotes (No membrane-bound organelles)
Cell wall with internal plasma membrane
Found everywhere
Bacteria
Special Features
• Pilus/pili - hairlike protrusion
– to stick to surfaces
– a bridge for sexual reproduction
• Flagellum - long, whiplike protrusion, for
moving
• Capsule - sticky layers around cell wall
• Toxin - a powerful poison
• Endospore – found in some bacteria
– resists harsh environments
Flagella
Capsules
Endospores
Endospores
Classification:
• Shape
– Cocci (Spheres), Bacilli (Rods), Spirilli (Spiral)
• Gram stain - Cell wall type
– Thick = Purple Stain = “Gram Positive”
– Thin = Pink Stain = “Gram Negative”
• Growth patterns
– Diplo- pairs
– Staphylo- clusters
– Strepto- chains
Shapes
Gram Stain
Growth Patterns
Streptococci
Pneumonia
PART II
Chapter 18
Archaebacteria & Eubacteria
Archaebacteria – ancient bacteria
Methanogens
Halophiles
Acidophiles:
Live in:
Live in:
Salt water
Live in:
Hot, acidic
water
Oxygen-free env.
Produce methane
gas
Eubacteria - “True” bacteria
• Live in more habitable environments
Heterotrophs
Saprophytes
(decomposers)
Photosynthetic
Autotrophs
Need sunlight to
make food
Parasites (cause Example:
disease)
Cyanobacteria
Chemosynthetic
Autotrophs
Need sulfur & nitrogen
to make food
Nitrogen fixation
(FIX the nitrogen)
Cyanobacteria - “blue-green bacteria”
Algae + Bacteria
Sulfur Bacteria
Beneficial Bacteria
• Nitrogen fixation
– Converts nitrogen into
ammonia
– a form that plants can use
• Nodules
– A symbiotic relationship
between bacteria and plants
(Beneficial Bacteria)
• Saprophytes (decomposers)
– Breaks down dead organisms and
decaying matter
– Returns nutrients to soil
(Beneficial Bacteria)
• Make food:
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Cheese
Pickles
Yogurt
Vinegar
Sauerkraut
Cellular Respiration
Obligate
Aerobes
Obligate
Anaerobes
Need Oxygen
Die from Oxygen
Pathogenic Bacteria –
disease-causing bacteria
• Pathogen – an organism
that causes disease
• Produce toxins
• Damage host’s tissues
• Enter through openings
in body (via air, food,
water)
Antibiotics:
~ Destroys cell wall
of bacteria
~ Creates holes in
the cell walls
• Sir Alexander Fleming
1928 - discovered Penicillium notatum
Air-Born
Air-Born Bacteria
Reproduction
Asexual
• Binary Fission
– Cell division
• Rapid - 20 min.
Sexual
• Conjugation – exchange
genetic material
• Pili/pilus - bridge
Binary Fission: Asexual Reproduction
Conjugation - Sexual Reproduction