1 EUBACTERIA (Bacteria) ARCHAEBACTERIA (Archaea) EUKARYOTES (Eukarya) The Prokaryotes • Only two groups • Archaebacteria and Eubacteria • Arose before the eukaryotes Prokaryotes—characteristics • Single-celled • Metabolically diverse • No nuclear membrane • Single chromosome • No organelles • Very small • Cell wall • Flagella rotate like propellers • Pili extend from the cell surface for adhesion or motion Ecological Importance of Prokaryotes • Decomposition • Nitrogen fixation • Mutualistic relationships • Parasitic relationships • Commercial uses Treponema pallidum, a spiral-shaped bacteria which causes Syphilis in humans Bacteria—what do they look like? Rods, spheres, spirals, vibrio Fig. 21-5, p.335 Prokaryotic Fission
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EUBACTERIA(Bacteria)
ARCHAEBACTERIA(Archaea)
EUKARYOTES(Eukarya)
The Prokaryotes
• Only two groups
• Archaebacteria and Eubacteria
• Arose before the eukaryotes
Prokaryotes—characteristics
• Single-celled
• Metabolically diverse
• No nuclear membrane
• Single chromosome
• No organelles
• Very small
• Cell wall
• Flagella rotate like propellers
• Pili extend from the cell surface for
adhesion or motion
Ecological Importance of
Prokaryotes
• Decomposition
• Nitrogen fixation
• Mutualistic relationships
• Parasitic relationships
• Commercial usesTreponema pallidum, a spiral-shaped bacteria which causes Syphilis in humans
Bacteria—what do they look
like?
Rods, spheres, spirals, vibrio
Fig. 21-5, p.335
Prokaryotic Fission
2
Bacterial Diversity
• Photoautotrophic
– Aerobic (Cyanobacteria)
– Anaerobic (Green bacteria)
• Chemoautotrophic
– Important in nitrogen cycle
• Chemoheterotrophic
– Largest group
• Bacteria, often in combination with yeasts
and molds, are used in the preparation of fermented foods such as:
– cheese, pickles, soy sauce, sauerkraut,
vinegar, wine, and yogurt.
• Bacteria are also important to numerous industrial processes,
– wastewater treatment
– industrial production of antibiotics and other chemicals.