Transcript Bacteria - University of Dayton

Bacteria
• What you don’t know
CAN hurt you!
(Bacteria Review)
What do you already know about
bacteria??
• Major Episodes in the History of Life
Millions of years ago
475
570
1,000
1,700
2,500
3,500
4,500
Major Episode
Plants and fungi colonize land
All major animal phyla established
First multicellular organisms
Oldest eukaryotic fossils
Accumulation of atmospheric 02
Oldest prokaryotic fossils
Origin of Earth
Visual Summary 15.1
• Two types of Prokaryotic organisms:
Eubacteria (bacteria) and Archaea
Prokaryotes
Domain Bacteria
Domain Archaea
(e.g., extremophiles)
Visual Summary 15.3
• Prokaryotic and eukaryotic cells differ in
several respects
Prokaryotic cell
Eukaryotic cell
Nucleoid region
Nucleus
Organelles
Figure 4.4
SUMMARY OF KEY CONCEPTS
• The Two Major Categories of Cells
Visual Summary 4.1
Review of Prokaryote Structure
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Plasma membrane
Outer cell wall
Big loop of DNA
Little loops of DNA (plasmids)
Ribosomes
Cytoplasm
Generalized structure of bacteria cell
Figure4.5x2
What’s going on?
Detriments to Humans
• Bad breath, tooth decay
• Food poisoning
• Some are pathogenic
pathogenic –
• Some diseases caused by bacteria:
• Strep throat, “staph” infection
• Cholera, “The Plague”, anthrax
• Syphilis, gonorrhea,
How cure bacterial infections?
(Antibiotics)
Homework:
Should we drop “bacteria bomb?”
• Are there benefits to bacteria that
outweigh their detriments to humans?
Benefits of Bacteria
• Decomposers!  chemical cycling
• Cyanobacteria were original producers of
oxygen atmosphere  ozone
• Origins of mitochondria & chloroplasts
• Aid humans in digestion (E. coli)
• Allow cows to digest cellulose (grass)
 milk, ice cream, hamburgers!
• Lactic acid fermentation
(yogurt, buttermilk, sauerkraut)
• bioremediation
• Nitrogen “fixers”
(to be explained in Unit IV!)
End