1. Viruses & Prokaryotes

2. What is a virus? Infectious agents Not an organism Why not?
1/100 the size of a bacterium
Pathogens – disease causing agents (mutagen – mutation causing agents) including viruses, bacteria, fungi, etc (“germ” not scientific)
infectious agents – not alive, not an organism b/c they require a host cell to replicate (cannot reproduce on their own)
referred to as obligate intracellular parasites – depends on the cellular metabolism of a host cell

3. Main differences: DNA or RNA viruses
Other differences: structure, shape, etc
Viruses can infect animals, plants, insects, bacteria, etc
They are usually species-specific, viral capsid proteins are bind to specific membrane proteins on host cells

4. Helical Icosahedral Complex Viral Shapes Basic Shape Example
                          
                                                                                  
Tobacco mosaic virus
Icosahedral
                                                    
                                                                       
      Herpes simplex
Complex
                                                 
                                                                             
        T-4 Bacteriophage

5. Viral Structure
Show HHMI animations

8. http://wikileon-period2. wikispaces

9. Staphylococcus aureus
Bacterial Shapes
Name
Basic Shape
Example
Coccus (sphere)
                                                              
                                                                                   
  Staphylococcus aureus
Bacillus
(rod)
                           
                                   (starting to divide)
                               
                                                 Salmonella typhi
Spirillum
(spiral)
                                                                 
                                                                           
Campylobacter jejuni

11. Viruses vs. Bacteria

12. Sources http://ppdictionary.com/viruses.htm