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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. Major Episode. 475 570 1,000 1,700 2,500 3,500 4,500. Plants and fungi colonize land
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Bacteria • What you don’t know CAN hurt you!
Major Episodes in the History of Life Millions of years ago Major Episode 475 570 1,000 1,700 2,500 3,500 4,500 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 Nucleoid region Eukaryotic cell Organelles Nucleus Figure 4.4
SUMMARY OF KEY CONCEPTS • The Two Major Categories of Cells Visual Summary 4.1
Review of Prokaryote Structure • Plasma membrane • Outer cell wall • Big loop of DNA • Little loops of DNA (plasmids) • Ribosomes • Cytoplasm
Detriments to Humans • Bad breath, tooth decay • Food poisoning • Some are pathogenicpathogenic – • 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!)