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Bacteria

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Bacteria

  1. 1. BACTERIA The Oldest Living Structures on the Earth! http://www.ted.com/talks/lang/en/bonnie_bassler
  2. 2. Kingdom Archaebacteria Most inhabit extreme environments on the earth. There are THREE main groupings. – Methanogens  Are anaerobic and live in swamps, marshes, the guts of animals, and sewage treatment ponds – Extreme Halophiles  Live in high salt areas such as the Dead Sea and the Great Salt Lake – Extreme Thermophiles  Live in hot springs with temperatures of 60oC to 80oC Cell walls do not contain peptidoglycan
  3. 3. Kingdom Eubacteria Prokaryotic Includes the spirochetes, gram-positive bacteria and cyanobacteria Live just about anywhere Have a cell wall that contains peptidoglycan (carbohydrate)
  4. 4. Kingdom Comparison EUBACTERIA ARCHAEBACTERIANuclear Absent AbsentEnvelopeMembrane Absent AbsentOrganellesPeptoglycan Present AbsentCell WallRibosomes Present Present
  5. 5. Size Relationships  10 Microns  Virus (.05 – 1 micron)  Bacteria (.05 – 1.5 microns)  Red blood cell (5 microns)  White blood cell (5-8 Microns)  Sperm (60 microns)
  6. 6. Bacterial Shapes  Bacillus bacteria are rod shaped  Cocci bacteria are round  Spirillum are spiral shaped
  7. 7. Groupings of Bacteria Individual Diplo – in pairs Strepto – in chains Staphlo – clustered like grapes
  8. 8. Identification Gram Stain – The gram stain differentiates bacteria on the basis of structure and composition of the layers of the cell wall. – After staining:  Gram positive bacteria appear purple  Gram negative bacteria appear pink. – Cell walls have a simpler structure than gram negative cell walls
  9. 9. Gram Stain
  10. 10. General Structure  Nearly all prokaryotes have cell walls  Bacteria have one major chromosome and rings of DNA called plasmids  Ribosomes are present to help in protein formation
  11. 11. General Structure RibosomePeptidoglycan Cell Cell wall membrane  Many disease causing bacteria have a thick outer slime capsule for protection  Many bacteria have small hair- Flagellum DNA Pili like pili to attach to other cells
  12. 12. Bacteria Cell Structure Single cell Nucleoid (plasmid) – Area where single DNA strand is found Flagella – For movement Capsule (Peptidoglycan) – Coating on outside of cell wall
  13. 13. Bacteria Cell Structure Cell Wall – Tough, rigid structure for support, shape and protection – Main function – prevent osmotic rupture – Water always moving in cell, so if cell wall OK, cell is OK – Bacteria growing in Penicillin grow holes in their cell walls, rupture, and die Cell membrane Ribosomes for making proteins
  14. 14. Bacteria Cell Structure Cells Alive: http://www.cellsalive.com/cells/bactcell.htm
  15. 15. Bacterial Reproduction Prokaryotes – Reproduce asexually by binary fission (cell splits apart) – Continually making new DNA in good conditions – In bad conditions, form endospore  Internal resting cell that surrounds the DNA, some cytoplasm, and thick outer coat  May live in for long time
  16. 16. Bacterial Reproduction Genetic Information Exchanged 3 Ways – Transformation  Genes taken up from the surrounding environment – Conjugation  Genes are transferred from cell to cell (sexually— through a tube) – Transduction  Genes are transferred between prokaryotes by viruses
  17. 17. Bacterial Population Growth Click on the icon above. Upon viewing the dividing bacteria, take note of the FOUR stages of the population growth curve
  18. 18. Aerobic vs. Anaerobic Aerobic  Anaerobic – Obligate aerobes – Obligate anaerobes  Must have oxygen  Must live where there is present to live no oxygen  Get energy from fermentation – Faculative anaerobes  Live where there is oxygen  Live where there is no oxygen
  19. 19. Bacterial Nutrition Autotrophs  Heterotrophs – Make own food – Decomposers – Smelly food caused by  Feed on dead plants bacteria that are and animals  Usually do not cause making food from disease substances that have  Ex: Nitrogen Cycle sulfur or iron – Parasites  Live on or in living organisms  Can cause disease
  20. 20. Economic Importance of Bacteria Nitrogen Fixation – All organisms need nitrogen to make proteins – Bacteria convert nitrogen to a form organisms can use Recycling of Nutrients – Necessary to breakdown the organic matter in dead organisms and wastes, returning nutrients to the soil
  21. 21. Economic Importance of Bacteria Food – Breakdown chemicals for their food by fermentation – Release other molecules we use because of distinct flavors and aromas (cheese, yogurt, sauerkraut) Medicines – Produce antibiotics which kill other bacteria
  22. 22. Economic Importance of Bacteria Disease – Only a few – About half of all human diseases are caused by bacteria
  23. 23. Food Bourne Bacteria Can Harm You Botulism Salmonella Staphylococcus E. Coli
  24. 24. Staphylcoccus
  25. 25. Staphylcoccus aureus
  26. 26. E. Coli bacteria
  27. 27. What type of Bacteria is this?
  28. 28. Staphylcoccus - MRSA
  29. 29. Bacteria Colonies
  30. 30. This is what we are going to do.

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