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Published byClement Ramsey Modified over 9 years ago
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BACTERIA & VIRUSES
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BACTERIA PROKARYOTIC in 2 of 3 Domains 1. Eubacteria 2. Archaebacteria
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EUBACTERIA ARCHAEBACTERIA LARGER MORE VARIETIES CELL WALL CONTAINS PEPTIDOGLYCAN SOME HAVE DOUBLE CELL MEMBRANE NO PEPTIDOGLYCAN MEMBRANE LIPIDS DIFFERENT SOME DNA SEQUENCES MORE SIMILAR TO EUKARYOTIC CELLS THAN TO EUBACTERIA
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Identification SHAPE CELL WALL COMPOSITION MOTILITY METHOD OF OBTAINING ENERGY PROKARYOTESEUBACTERIACYANOTROPHICHETEROTROPHICARCHAEBACTERIAHELIOTROPHSTHERMOTROPHSMETHANOGENS
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SHAPES 1. BACILLI 1. RODS 2. COCCI 1. BALLS 3. SPIRILLA 1. CORK- SCREW
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Anaerobes Aerobes I. Obligate I. Cannot tolerate oxygen II. Faculative I. +/- oxygen Obligate Oxygen required Oxygen Tolerance
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Binary Fission asexual reproduction trigger: growth reaches 2x http://www.classzone.com /books/hs/ca/sc/bio_07 /animated_biology/bio_ ch05_0149_ab_fission.h tml Growth & Reproduction
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Conjugation Exchange of DNA thru hollow bridge that forms between 2 bacteria Increases genetic diversity http://highered.mcgraw- hill.com/sites/dl/free/00 72835125/126997/anima tion6.html http://highered.mcgraw- hill.com/sites/dl/free/00 72835125/126997/anima tion6.html Growth & Reproduction
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Endospore Formation Used when environmental conditions unfavorable Dormancy can last years Growth & Reproduction
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Importance of Bacteria 1. DECOMPOSERS 2. NITROGEN FIXERS 3. INDUSTRIAL USES 4. SYMBIOSIS in HUMANS
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TRANSFORMATION of BACTERIA During transformation a cell takes in DNA from outside the cell becoming a permanent component of the cell’s genome.
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PLASMIDS SMALL CIRCULAR PIECE OF DNA NATURALLY FOUND IN SOME BACTERIA CONTAINS DNA THAT PROMOTES REPLICATION HAS GENETIC MARKER
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PLANTS ANIMALS CAN REMOVE CELL WALL & CELL MAY SPONTANEOUSLY TAKE UP FOREIGN DNA OR INJECT PLASMIDS INTO CYTOPLASM GENES CAN BE REPLACED EUKARYOTIC CELL TRANSFORMATION
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Pathogens disease-causing agents
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Bacterial Infections Louis Pasteur 1 st to prove bacteria can cause disease bacteria produce illness in 1 of 2 ways: 1. directly damage host cells or tissues 2. release toxins (poisons) that then circulate throughout body interrupting homeostasis
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Preventing Bacterial Disease vaccines: preparation of killed or weakened pathogens that prompts the immune system of the organism to produce immunity to the disease should they ever come in contact with it
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Treating Bacterial Infections antibiotics: compounds that block reproduction of bacteria or kill them availability of antibiotics (since ~WWII) has been 1 of major reasons life expectancy increased dramatically during the 20 th century
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Controlling Bacterial Growth heat sterilization: destroys bacteria by heating equipment used on patients to ~ 125 ◦ C using either moist heat or dry heat disinfectants: chemical solutions that kill bacteria, overuse in homes (antibacterial soaps) increase chance of resistance food processing: food stored @ lower temperatures stays fresher longer because it decreases the bacterial reproductive rate; cooking food before consumption also kills bacteria
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VIRUSES NON-LIVING MADE OF A PROTEIN COAT (CAPSID) SURROUNDING NUCLEIC ACID
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Bacteriophage Tobacco Mosaic Virus
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Influenza Virus Rhinovirus
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Lytic Lysogenic Cell infected with 1 virus Takes over host cell metabolism Make many copies of nucleic acid & capsids assemble Cell bursts (lysis) releasing many copies of virus Cell infected with 1 virus Its DNA inserts into bacteria’s loop of DNA Replicates as that cell goes through cell division 2 Types Viral Infection
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LYTIC CYCLE
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LYSOGENIC CYCLE
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Animations http://www.bio-alive.com/animations/virology.htm
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Viral Disease in Humans viruses make you sick by disrupting homeostasis in tissues and cells of your body viruses cannot be treated with antibiotics best protection is prevention Vaccines : measles, mumps, chicken pox, influenza, HPV treatment: once sick symptoms treated often with OTC products, some anti-viral meds available
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Viral Diseases in Animals viruses produce serious animal disease examples: hoof-and-mouth (or foot-and-mouth), BPV, swine flu, bird flu
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Viral Disease in Plants threat to agricultural plants because plant cells surrounded by a cell wall the plant viruses have a more difficult time infecting cells many plant viruses have adaptations that allow them to enter damaged cells (small tear in a leaf means some cells damaged)
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VIRUSES / CELLS COPY FIGURE 19-11 FROM PAGE 483 OF BOOK ONTO PAGE 113 of notebook Draw a virus and a bacteria of your choice, label their parts and write a 2 paragraph reflection on what you have learned about bacteria & viruses.
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