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Bacteria and Viruses

Bacteria and Viruses. Brought to you by Mr. Brinkman. Taxonomy. The branch of biology dealing with the classification of life. 1700s 2 kingdoms : plant and animal 1800s 3 kingdoms : plant, animal, and protista 1950-1990s 5 kingdoms : plant, animal, protista, fungi, monera

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Bacteria and Viruses

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  1. Bacteria and Viruses Brought to you by Mr. Brinkman

  2. Taxonomy • The branch of biology dealing with the classification of life. • 1700s 2 kingdoms: plant and animal • 1800s 3 kingdoms: plant, animal, and protista • 1950-1990s 5 kingdoms: plant, animal, protista, fungi, monera • Present: 6 kingdoms: eubacteria, archaebacteria, protista, animal, plant, fungi

  3. Prokaryotes • Traditionally all prokaryotes • Presently, the prokaryotes are divided into two kingdoms. • Archaecbacteria • Eubacteria

  4. Eubacteria • Larger of the two kingdoms • Live almost everywhere • Vital for life functions and industry • Both helpful and harmful

  5. Archaebacteria • Comes from the Greek word archaio which means “ancient” • Believed by many to be the earliest organisms to inhabit the earth • All live in harsh environments • 3 separate phyla:

  6. 1. Methane-producing bacteria (methanogens) • Intestinal tracts of animals • Bottoms of swamps • Used for sewage treatment

  7. 2. Salt-loving bacteria (Halophiles) • Thrive in high salinity waters where no other life can exist. • Great Salt Lake • Dead Sea

  8. 3. Hot-acidic loving (thermoacidophiles) • Thrive at temperatures as great as 180ºF and pHs as low as 2. • Natural springs. • Yellowstone National Park

  9. Facts about bacteria: • Found everywhere • Very small. Much smaller than any cell in our body. • No membrane-bound structures or nucleus. (prokaryotes) • Usually surrounded by a cell wall and a capsule for additional protection.

  10. General structure:

  11. Classification according to shape. • Coccus (spherical) • Can be single cells • Pairs • Chains

  12. 2. Bacillus (rod) • Single cells • Pairs • Chains • example • anthrax

  13. 3. Spirillum(spiral) • Only exist as single cells Example: cholera, syphillis

  14. Shapes:

  15. Aerobic The most common type Cannot live without oxygen Anaerobic Cannot live in the presence of oxygen Gets energy through fermentation (CO2) Metabolic Needs

  16. Decomposer Feed off the remains of dead plants and animals. Seldom cause disease Parasites Live on or in other living organisms. Often cause disease Heterotrophic bacteria

  17. Photoautotroph Use sunlight to convert carbon dioxide into energy Ex. cyanobacteria Chemoautotroph Use inorganic chemical compounds to convert carbon dioxide into energy. Autotrophic bacteria

  18. Genetic material • Nucleoid= a single circular chromosome containing the DNA and RNA. • Endospore = tough protective coat that covers and protects the nuclear material.

  19. Reproduction • All reproduce asexually • Usually through binary fission • Under certain conditions, bacteria can reproduce very quickly • A small colony can double in 20 minutes.

  20. Binary fission • The most common type of asexual reproduction. • A single cell splits to form two daughter cells

  21. Exchange of DNA Conjugation = genes move from one cell to another

  22. Endospores • A thick covering around the DNA that allows the bacterium to remain dormant for long periods of time. If necessary, many years.

  23. Helpful bacteria • Decompose food wastes • Produce vitamins • Produce antibodies • Genetic engineering • Decomposition of dead plants and animals • Industry & agriculture

  24. Plant roots • Found on the roots of plants. • Can be helpful in ‘fixing’ nitrogen for plant use. • Rhizobium nodules on roots of soybeans

  25. VIRUSES • Are they living or non-living? • Contain genetic material • Lack organelles • Cannot reproduce unless inside a host cell. • The word virus comes from the Greek word for POISON • Cause many diseases.

  26. How big is a virus? • Much smaller than bacterial cells. • Scientists have only recently, last 60 years, learned anything about viruses • Classified according to the types of cells they attack.

  27. Virus structure: • A center core of DNA or RNA surrounded by a protein coat called a capsid.

  28. LYTIC CYCLE Injects its nucleic acid (DNA or RNA) into the cell to take over cellular activities. LYSOGENIC CYCLE Coexists with the cell without destroying the host cell 2 main types of viral reproduction:

  29. Lytic cycle

  30. Lysogenic cycle

  31. RETRO-VIRUS • Direct the production of proteins by the host cell. • RETROVIRUS = A special type of virus that can make DNA which will produce new RNA, which, in turn, makes proteins that produce new viruses. • Ex. AIDS VIRUS

  32. Diseases caused by microorganisms: • Pathogens: disease-causing agents • BACTERIAL DISEASE: • Damage cells and tissues directly • Release toxins to interfere with normal cellular activity

  33. Common bacterial diseases: • LymeSdisease • Tetanus • Strep throat • Tuberculosis • E. coli poisoning

  34. Controlling bacterial disease. • ANTIBIOTICS • 1928. Discovery of penicillin by Sir Alexander Flemming • Came from a mold.

  35. Common methods of bacterial infection. • Food & water (E. coli) • Coughing & sneezing • Sexually transmitted. • Carried by insects

  36. Food disease prevention • Keep hands, and cooking utensils clean • Canning and preservation techniques with food. • Pasteurization • Freezing

  37. How do we prevent viral diseases? • Cannot be treated with ordinary antibiotics • Vaccinations. The word comes from the vacca Latin for “cow”. • A vaccine is a weakened form of a virus that is used to stimulate the immune system to produce antiviral substances.

  38. Edward Jenner (1749-1823) • British physician • Developed the first vaccine in 1798 for the viral disease smallpox. • Considered the “Father of Immunology”

  39. Common viral diseases: • AIDS • Measles • Chickenpox • Smallpox • Influenza • The common cold • West Nile • Polio

  40. SMALL POX • Viral disease that is believed to have originated in Egypt at least 2000 years ago. • Characterized by pox lesions and boils. • Spread to the Americas by Spanish conquistadors. • Jenner’s vaccine was developed after observing a bovine disease: “cowpox”

  41. Eradication of smallpox:Or is it? • In 1967 the World Health Organization launched a global effort to eradicate smallpox. • 1978 : Last known case of smallpox. • 1980 : W.H.O. declares the world free of smallpox. • Is there any smallpox virus left?

  42. Viroid Small disease causing particle. Affect plants Prion Small disease causing particle. Affects animals. example: Viroids and Prions MAD COW DISEASE

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