Bacteria

• Types of cell

  • Prokaryotes
  • Eukaryotes
• Eukaryotes


  • Larger
  • Have membrane bounded organelles: Nucleus, ER, Golgi body, Mitochondria, vacuole, lysosome, chloroplast

  
• Prokaryotes

  • Smaller
  • NO membrane bounded organelles
• Germ concept of disease

  Every infectious disease is caused by a specific germ
• Germ concept of disease was proposed by Louis Pasteur
• Characteristics of bacteria

  • Microscopic
  • Unicellular
  • Prokaryotes (before nucleus)
  • No membrane bounded organelles

  
• Anatomy of a bacterial cell

  • Cell wall
  • Cell membrane
  • Cytoplasm
  • Ribosomes
  • Nucleoid region –where the DNA is located
  • Plasmid – circular DNA
  • Pilli – for exchanging DNA
  • Flagella – whip like structure for the movement
  • Capsule – Outermost protective covering
  • Slime layer – additional protection
• Modes of nutrition

  • Heterotrophic - must obtain their food from other sources
  • Autotrophic - Photosynthetic bacteria, Chemosynthetic bacteria - able to make their own food
• Binary fission


  One cell splits into two cells
• Kingdoms of bacteria

  • Archaebacteria (Extreme Bacteria)
  • Eubacteria (True Bacteria)
• Types of Archaebacteria

  • Thermophiles - Heat loving, found in volcanos and hot sulfur springs
  • Halophiles - Found in salty environment, Dead Sea
  • Methanogens - Methanococcus jannaschii, Methane producing, Found in volcanic vents and stomach of cattles
  • Psychrophiles - Cold loving, can grow at 0 ⁰C and even as low as -10 ⁰ C
• Eubacteria

  • Lactobacillus shirota strain - aids digestion
  • Cyanobacteria - blue-green algae, photosynthetic bacteria
  • Streptococci pyogenes - causes sore throat
  • Clostridium botulinum - dangerous food poisoning, produced by anaerobic bacteria, can live tightly sealed can
  • Helicobacter pylori - causes Peptic ulcer
  • Staphylococcus aureus - Staph food poisoning and skin disorders
  • Genus Mycobacterium - leprosy and tuberculosis
  • Genus Salmonella - Food poisoning
  • Streptococcus mutans - tooth decay
• Koch's postulate is a set of guidelines for determining if a particular bacterium can cause a disease