PART I Chapter 18 Archaebacteria & Eubacteria

Archaea 7:16 min

Phylogeny

Characteristics First living evidence of life on earth Unicellular Prokaryotes (No membrane-bound organelles) Cell wall with internal plasma membrane Found everywhere

Bacteria

Bacteria Structures Cell wall – provides support and protection to the cell Plasma membrane – flexible, selectively permeable boundary that controls what enters and leaves the cell Cytoplasm – semi-fluid material inside the cell’s plasma membrane Ribosome – organelle that helps to manufacture proteins DNA - stores and communicates genetic information for the cell

Bacteria Structures Pilus/pili - hairlike protrusion to stick to surfaces a bridge for sexual reproduction Flagellum - long, whiplike protrusion, for moving Capsule - sticky layers around cell wall Toxin - a powerful poison Endospore – found in some bacteria - resists harsh environments

Reproduction Asexual Binary Fission Cell division Rapid - 20 min. Sexual Conjugation – exchange genetic material Pili/pilus - bridge

Classification: Three Basic Shapes Cocci - Spheres Bacilli - Rods Spirilli - Spiral

Classification: Gram stain – Cell wall type Thick – Purple Stain = “Gram Positive” Thin - Pink Stain = “Gram Negative”

Growth Patterns Diplo- pairs Staphylo- clusters Strepto- chains

Streptococci

Eubacteria - “True” bacteria Heterotrophs Photosynthetic Autotrophs Chemosynthetic Autotrophs Saprophytes (decomposers) Need sunlight to make food Need sulfur & nitrogen to make food Parasites (cause disease) Example: Cyanobacteria Nitrogen fixation (FIX the nitrogen) Live in more habitable environments

Bacteria – 11:03 minutes

Beneficial Bacteria Nitrogen fixation Converts nitrogen into ammonia a form that plants can use Nodules A symbiotic relationship between bacteria and plants

Beneficial Bacteria Saprophytes (decomposers) Breaks down dead organisms and decaying matter Returns nutrients to soil

Beneficial Bacteria is used to Make food: Cheese Pickles Yogurt Vinegar Sauerkraut

Pathogenic Bacteria – disease-causing bacteria Pathogen – an organism that causes disease Produce toxins Damage host’s tissues Enter through openings in body (via air, food, water)

Air-Born

Air-Born Bacteria

Antibiotics: Destroys cell wall of bacteria Creates holes in the cell walls Sir Alexander Fleming discovered Penicillium notatum

The Immune System - 13:46 minutes

The End of Bacteria; Start Viruses!

Viruses - 8:05 minutes Viral Replication - 10:29 minutes