Transcript Chapter 18 Archaebacteria and Eubacteria

PART I
Chapter 18
Archaebacteria & Eubacteria
Phylogeny
Characteristics
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First living evidence of life on earth
Unicellular
Prokaryotes (No membrane-bound organelles)
Cell wall with internal plasma membrane
Found everywhere
Bacteria
Bacteria Structures
• Cell wall – provides support and protection to
the cell
• Plasma membrane – flexible, selectively
permeable boundary that controls what enters
and leaves the cell
• Cytoplasm – semi-fluid material inside the
cell’s plasma membrane
• Ribosome – organelle that helps to
manufacture proteins
• DNA - stores and communicates genetic
information for the cell
Bacteria Structures
• 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:
Three Basic Shapes
Cocci Spheres
Bacilli Rods
Spirilli Spiral
Classification:
• Gram stain –
Cell wall type
• Thick –
Purple Stain =
“Gram Positive”
• Thin - Pink Stain =
“Gram Negative”
Growth Patterns
Diplo- pairs
Staphylo- clusters
Strepto- chains
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
environment
Produce
methane gas
Eubacteria - “True” bacteria
Live in more habitable environments
Heterotrophs
Photosynthetic
Autotrophs
Saprophytes
(decomposers)
Need sunlight to
make food
Chemosynthetic
Autotrophs
Need sulfur &
nitrogen to make
food
Parasites
(cause disease)
Example:
Cyanobacteria
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