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Chapter 19 Bacteria & Viruses
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I. Bacteria Are ________________________-lack a nucleus and have few organelles Much smaller than eukaryotes Eubacteria-larger kingdom than archaebacteria;usually have protective cell wall and determines shape Prokaryotes
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__________________________-not such a strong,if any,cell wall,DNA sequences more like eukaryotes;live in HARSH environments like hot springs or volcanic vents Archaebacteria
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Identifying bacteria: –by shape 1) rod-shaped are __________________ 2) spiral-shaped are_______________________ 3) spherical-shaped are cocci(coccus- singular) Bacillus or bacilli Spirillus or spirilla
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by cell walls-use Gram Staining-Gram(+) have thick_______________________walls/gram(-) have thinner walls by movement-some do not move and some have flagella peptidoglycan
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B. Metabolic Diversity Heterotrophs –_____________________-must take in organic molecules for energy and supply of Carbon-as do we –_____________- Autotrophs –____________________- –______________-as those found in volcanic vents Chemoheterotrophs photoheterotrophs photoautotrophs chemoautotrophs
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Releasing Energy –1) Obligate aerobes-need constant supply of O2 –2) _______________________-do not need O2 –3) Faculatative anerobes-can survive w/or w/o O2-example-E.coli Obligate anaerobes
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C. Growth and Reproduction _________________________grows,replicates DNA and splits in half Binary fission
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________________________-exchange genetic info w/ a “bridge” conjugation
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Some produce_________________________, which can lie dormant and germinate spores
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D. Importance of Bacteria Decomposers N-fixers-for plants Human uses-food production ;cleaning up oil spills Assist digestion
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II. Viruses-particles of nucleic acids,protein and sometimes lipids
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Not living-reproduce only by infecting living cells Usually has a DNA or RNA core w/outer protein coat Outer protein coat called a ______________-which enable it to enter a host cell—often destroying host cell ________________________-viruses that infect bacteria capsid bacteriophage
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____________________infection-virus enters cell,makes copies,and causes cell to burst _____________________________-virus integrates DNA into DNA of host cell,and viral genetic info replicates along w/host Lytic Lysogenic
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_______________________________- contain RNA as genetic info and produce DNA copy of RNA retroviruses
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III. Diseases Bacterial –Infect by damaging cells or releasing toxins –Mycobacterium tuberculosis –Streptococcus –Cornyebacterium diptherae –Anthrax –Lyme’s disease –Tetanus –Meningitis –Tooth decay prevention –-_______________________preparation of weakened or killed pathogens –________________________-compounds that block the reproduction or growth of bacteria vaccination antibiotic
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2)control- sterilization,heat,disinfectantants,proper food processing and storage
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B. Viral Common cold Influenza Smallpox Warts AIDS Chickenpox Measles Hepatitis A,B, or C West Nile Polio
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–________________________________single- stranded RNA moleculesw/no capsid-attack plants –______________________-virus –like particles of protein-may cause protein clumps that induce new prions---example-Mad Cow Disease viroids prions
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