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Chapter 13: Bacteria and Viruses Essential question: How do bacteria and viruses affect our lives? I. Prokaryotes: single celled organisms that do not have nucleus A. Domains: Archaea and Bacteria 1. Bacterial fossils found are about 3.5 billion years old 2. Evolved into many different forms and live in almost every environment Section 19-1 Concept Map Bacteria are classified into the kingdoms of Eubacteria Archaebacteria include a variety of lifestyles such as Living in soil Go to Section: Infecting large organisms live in harsh environments such as Thick mud Animal digestive tracts Salty lakes Hot springs B. Classification 1. Domain Bacteria: Kingdom Eubacteria: often called bacteria a) many different shapes and sizes b) shapes: bacilli – rod shaped, cocci-spherical, and spirilla- spiral c) Gram-negative bacteria: complex cell wall and small amounts of peptidoglycan (proteincarbohydrate compound) d) Gram-positive bacteria: simpler and have more peptidoglycan Gram stain 2. Domain Archaea: Kingdom Archaebacteria: more ancient a) unusual lipids in cell membrane and no peptidoglycan in their cell walls b) live in extreme environments c) methanogens: get energy by changing H2 and CO2 into methane gas d) extreme halophiles: live in high salt concentrations e) thermoacidophiles: acidic and high temperature environments Archaebacteria at Yellowstone National Park Morning Glory Hot Spring Grand Prismatic Spring Fumarole with sulfur Mammoth Hot Springs Mud Pots Imperial Geyser II. Biology of Bacteria A. Structure 1. Cell wall: most bacteria have a cell wall 2. Cell membrane and cytoplasm: lipid bilayer a) carries out cellular respiration b) photosynthesis if it is a photosynthetic bacteria c) cytoplasm: contains ribosomes and DNA 3. Capsules: outer covering that helps to protect bacteria from drying out or harsh chemicals Capsule 4. Pili: short, hairlike protein structures helps bacteria cling to host cells Pili 5. Endospores: dormant structure that is produced during harsh environmental conditions 6. Movement structures a) flagella b) glide through slime layer 7. DNA: single closed loop of double-stranded DNA attached to the cell membrane a) plasmid: small circular loops of DNA that carry genes that enable the bacteria to cause disease or resist antibiotics bacteria Section 19-1The Structure of a Eubacterium Ribosome Peptidoglycan Cell Cell wall membrane Flagellum Go to Section: DNA Pili Extra Credit Option : Due Fri. Feb. 12 Watch the movie Contagion Write a summary (paragraph) about the movie by answering the following questions • Where did the virus come from (country, animal species, original two people) • How was the virus spread? • Why did it spread so quickly? • Why did it take so long to make a vaccine? B. Nutrition and growth 1. Heterotrophs and autotrophs 2. Phototrophs: get energy from light 3. Chemotrophs: get energy from chemicals taken from the environment 4. Four ways a) photoheterotroph: uses light but gets its carbon from organisms b) chemoheterotroph: obtains energy and carbon from other organisms c) photoautotroph: uses light energy and gets carbon from CO2 d) chemoautotroph: energy from compounds and gets carbon from CO2 C. Prokaryotic habitats 1. Obligate anaerobes: cannot survive in oxygen 2. Facultative anaerobes: can live with or without oxygen 3. Obligate aerobes: require oxygen D. Genetic recombination: three nonreproductive ways that bacteria get new genetic material 1. Transformation: takes in DNA from its environment Transformation 2. Conjugation: two living bacteria bind together and one transfers genetic information to the other Conjugation 3. Transduction: virus obtains DNA from a host and as the viruses replicates inside the bacteria the new DNA is added Transduction III. Bacteria and Humans A. Bacteria and Disease 1. Pathology: study of diseases 2. Pathogen: bacteria that cause disease 3. Toxins: poisons produced by bacteria that cause disease 4. Bacteria can cause disease by destroying body tissue Section 19-2 Common Diseases Caused by Bacteria Go to Section: Disease Pathogen Prevention Tooth decay Streptococcus mutans Regular dental hygiene Lyme disease Borrelia burgdorferi Protection from tick bites Tetanus Clostridium tetani Current tetanus vaccination Tuberculosis Mycobacterium tuberculosis Vaccination Salmonella food poisoning Salmonella enteritidis Proper food-handling practices Pneumonia Streptococcus pneumoniae Maintaining good health Cholera Vibrio cholerae Clean water supplies 5. Antibiotics: drugs that combat bacteria by interfering with various cellular functions 6. Antibiotic resistance: bacteria most susceptible to the antibiotic die first, but some are resistant and grow Resistance B. Useful bacteria 1. Decomposers: break down remains of organic matter in dead plant and animal waste allowing organic compounds to become available to other organisms 2. Used in sewage treatment plants 3. Producing and processing food like sour cream, yogurt, cheese, pickles, and sauerkraut Foods 4. Industrial chemical production: mining for minerals and petroleum, insecticides, cleaning up oil spills Bacteria Health Pamphlet 1. Title and pictures 2. List several ways to prevent disease 3. Antibiotics used to treat bacterial disease 4. List several ways that bacteria are helpful to humans 5. List several examples of bacterial diseases (p. 472) IV. Virus Structure A. Virus: nonliving particle composed of DNA or RNA and a protein coat 1. Virology: study of viruses B. Characteristics of viruses 1. One of the smallest biological particles capable of causing diseases 2. Viruses can only replicate by infecting cells and using the cell’s organelles to make new virus particles 3. Made up of nucleic acid (DNA or RNA) and protein coat called capsid 4. Shapes: helical and icosahedral (20 triangular faces) 5. Classified by whether they have RNA or DNA and whether it is singled and double stranded Virus V. Viral Replication A. Bacteriophage: viruses that infect bacteria 1. Structure: icosahedral head with tail and tail fibers Bacteriophage B. Lytic cycle lytic 1. Virus invades a host by injecting its DNA 2. Produces new viruses 3. Cell breaks open and releases the new viruses C. Lysogenic cycle 1. Virus injects DNA into cell 2. DNA integrates into the host cell’s DNA 3. DNA of host cell replicates and so does the virus’s DNA 4. Each bacterial offspring will be carrying the DNA of the virus 5. At some point the cell will go into the lytic phase and destroy the cell Lysogenic VI. Viruses and Human Disease A. Infectious diseases: can affect various organs in the human body including brain, liver, heart, lungs, and skin 1. Common cold, chickenpox, measles 2. Mumps, polio, rabies, AIDS, and hepatitis 3. Some viruses can cause cancer by blocking the normal controls on cell reproduction a) HPV: human papillomarvirus can cause cervical cancer (there is a vaccine for this virus) b) hepatitis B can cause liver cancer Section 19-3 Common Diseases Caused by Viruses Go to Section: Type of Virus Nucleic Acid Disease Oncogenic viruses DNA cancer Retroviruses RNA cancer, AIDS Adenoviruses DNA respiratory infections Herpesviruses DNA chickenpox Poxviruses DNA smallpox 4. Emerging disease: illnesses caused by new or reappearing infectious agents that typically exist in animal populations a) wild and domestic animals can have viruses that can be transmitted to people b) Avian or bird flu is due to close interaction of people and poultry on farms and in markets around the world B. Prevention and treatment 1. Vaccines: prevent the disease by giving inactive virus to stimulate the body’s immune system to provide protection against the pathogen 2. Antiviral drugs: given to infected patients and it interferes with viral nucleic acid synthesis (very few types of drugs) 3. Antibiotics can not destroy viruses, only bacteria Vaccine 4. 4. Vector control: control of animal vectors that carry the virus a) Mosquito control to stop yellow fever b) Rabies vaccinations to keep pets from of rabies and prevent spread to humans Virus Research Answer the following questions using the reference books on the lab tables. Research 1 viral diseases. 1. 2. 3. 4. Name of the viral disease Where is it found in the world? Is there a vaccine or way to prevent? What are 2 symptoms of the disease?