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Published byMarsha Gray Modified over 9 years ago
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Types of Heterotrophic Nutrition
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Methods of Feeding 1.Saprophytic Nutrition – feed on dead organic matter, get energy from it, and recycle it back into the environment. decomposers. 2.Parasitism – organism (parasite) feeds off of another (host) at the expense of the host. 3.Predation – - organism (predator) hunts, kills, and eats another organism (prey). 4.Scavenging – feed on organisms killed by something else.
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What are Bacteria? Bacteria are PROKARYOTES – The smallest known living cells They are found everywhere!! Bacteria on head of a pin Starr, 317 Bacteria in dental plaque microbeworld.org Did you know? There are over 80 species of bacteria in your mouth!
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Obtaining Energy Autotrophs (make energy) – Photoautotrophs- capture energy from light Ex- cyabobacteria – Chemiautotrophs- obtain energy from chemical reactions with inorganic molecules (ammonia, hydrogen sulfide, nitrites, sulfur, Iron) Ex. Ocean vent bacteria
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Cyanobacteria bloom
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Obtaining Energy cont… Heterotrophs- most bacteria obtain their energy from organic molecules – These bacteria are often feeding in, on and around us… Some bacteria are photoheterotrophs – Capture sunlight and digest organic molecules
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Releasing Energy Bacteria can use both cell respiration and fermentation Many bacteria have different oxygen requirements: – Obligate aerobes- must have oxygen for respiration – Facultative anaerobes- can function with or without oxygen – Obligate anaerobes- poisoned by oxygen (use fermentation)
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Three basic shapes of Bacteria Spherical – coccus Rod – bacillus Coiled - spirillum Schraer, 633
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Shapes of Bacteria
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Coccus Spheres Cocci (plural) a variety of arrangements
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Diplobacillus (paired) Bacillus Cylindrical or rod-shape Bacilli (plural) Variations in cell arrangement
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Spirals Vibrio Spirillum Spirochete
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Simple Colonies Staphylo = clusters Strepto = chains Staphylococcus wisc.edu Diplo = double Diplococcus cat.cc.md.us Streptobacillus
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Some have flagella - made of rope-like proteins, not microtubules. Some slide on a slimy secretion. Many can form dormant cells called endospores to survive harsh conditions. Salmonella www.iwate.jp Streptomyces spores Many can MOVE
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Bacterial Reproduction Bacterial cells reproduce asexually through fission which is the splitting of a cell into two new cells.
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Bacterial Reproduction cont… Some bacteria utilize conjugation to exchange pieces of genetic information to increase variation – *Not considered sexual reproduction- not complete exchange of DNA, no offspring made
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