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Bacteria

Bacteria. Characteristics of Bacteria. Bacteria – microscopic prokaryotes (unicellular no nucleus) - live everywhere (living and dead) - outnumber cells on your body 10 to 1 Archaea – microscopic prokaryote - live in extreme environments (warm no O 2 )

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Bacteria

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  1. Bacteria

  2. Characteristics of Bacteria • Bacteria – microscopic prokaryotes (unicellular no nucleus) - live everywhere (living and dead) - outnumber cells on your body 10 to 1 • Archaea – microscopic prokaryote - live in extreme environments (warm no O2) - ribosomes resemble that of eukaryotes - contain molecules in plasma membrane found in no other organism

  3. Structure of Bacteria • Consist of • Cell Wall – Can have a thick capsule surrounding it preventing antibiotics from killing it (pneumonia) - pili surrounding it allow the bacterium to stick to surfaces • Cell Membrane • Cytoplasm – contains ribosomes • DNA – one coiled circular chromosome • Size • 1 – 5 μm (100 fit across the top of a pin head) • Shape • Round • Rod • Spiral

  4. Obtaining Food and Energy • Various ways due to living area • Dead organisms or organic waste • Take in and break down • Living hosts • Bacteria that causes tooth decay (live on plaque and feed on sugars) • Aerobic – oxygen needed • Anaerobic – oxygen NOT needed

  5. Movement • Flagella – long whip-like structures used for movement • Twist movement • Spiral movement • Pili – sticky structures

  6. Reproduction • Asexual – one parent • Fission – cell division forming two identical cells - NO genetic variation • Conjugation – two bacteria of the same species attach to each other and combine their genetic material - two still remain (no new organisms are produced) - DNA is different – Genetic Variation

  7. Survival Tactics • Endospores – a bacterium builds a thick internal wall around its chromosome and part of the cytoplasm - protects the bacterium form * heat * cold * drought - remain dormant for months to centuries

  8. Lesson Review Pg. 236 # ‘s 1 - 11

  9. Viruses

  10. Characteristics of Viruses • Virus – a strand of DNA or RNA surrounded by a layer of protein that can infect and replicate in a host cell. • Consist of • NO NUCLEUS • NO CELL WALL • NO ORGANELLES • Size • Smaller than bacteria • Shape • Cylinder • Crystal • Sphere • Bacteriophage

  11. Dead or Alive • Have Life • Organization • Response to stimuli • Reproduction • Use energy • Grow • Virus – None of the above characteristics - not alive

  12. Host Cell • Host Cell • Used to replicate virus DNA • Viruses inside a host cell • Active – replication occurs instantly • Latent – dormant

  13. Replication Fig 13 pg. 248 - 249

  14. Mutations • Mutations • Virus - adjust changes to host cell. • Host cell – changes to prevent virus attachment

  15. Viral Diseases • Chicken pox • Influenza • Pneumonia • Symptoms • Runny nose • Scratchy throat • NO SYMPTOMS HIV

  16. Immunity • Immunity – free from disease • Antibodies – protiens that attach to pathogens and make them useless • Aquired immunity – after having the illness • Natural immunity – passed from mother to child • Two actions are taken • Prevention from attachment • Attach and destroy virus

  17. Vaccines • Vaccine – contains one or more deactivated pathogens • Triggers production of antibodies • Mild symptoms

  18. Good Use for Viruses • Treat genetic disorders • Gene transfer – inject normal genes into mutated ones.

  19. Lesson Review Pg. 253 # ‘s 1 - 11

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