 Prokaryotic single cells  Shapes ◦ Sphere (cocci), Rod (bacilli), or Spiral (spirilli)  Organization ◦ Often clusters (staphylo-) or chains (strepto-)

 Eubacteria have cell walls ◦ Gram negative have 2 nd cell wall ◦ Gram positive do not ◦ Negative = no antibiotics  Movement ◦ Many have flagella

 Binary Fission – happens QUICKLY!

 Obligate anaerobes ◦ Clostridium botulinum  Facultative anaerobes/aerobes ◦ E. coli  Obligate aerobes ◦ Tuberculosis

 Autotrophic ◦ Photosynthetic (Cyanobacteria) ◦ Chemosynthetic (Methanogens)  Heterotrophic ◦ Parasitic (Tuberculosis) ◦ Decomposers

 Beneficial ◦ Decomposers ◦ Manufacture of food – yogurt, cheese, pickles  Pathogens – disease-causing ◦ Food poisoning

 Francesco Redi – Spontaneous Generation

 Airborne  Water  Direct contact  Vectors - transmitters of disease that carry the pathogens from one host to another

 Antibiotics ◦ 1928 Fleming – penicillin mold toxic to bacteria  Antibiotic Resistance ◦ Not all bacteria die from antibiotics ◦ People don’t finish prescription ◦ Over-prescribed

 NONLIVING pathogens ◦ Do not metabolize, grow, or maintain homeostasis  Structure – RNA or DNA with protein capsid

 Rely on living cells (hosts) for replication  Insertion of either the entire virus or just the DNA into the host cell

 Some viruses turn the cell into a virus making factory, bursting the cell with new viruses  Other viruses replicate slowly and can lay dormant before take-over

 CLICK! CLICK!

 Vaccines – inject dead or weak virus so the body can form antibodies ◦ Edward Jenner – 1800s - smallpox  Anti-viral drugs – try to disable replication in some way