1. Microbiology Introduction to Viruses Living or non-living? Sarah L. Bacon Assignment # 11/336 sarahlbacon@hotmail.com

2. New Unit Microbiology - Viruses w Micro (small) biology (study of living organisms) w Viruses = Latin for poison w Closely linked with many organisms. w Source of disease and death including AIDS, influenza,Ebola,colds

3. Objectives of today’s lesson w To describe the basic structure and function of a virus w To evaluate the evidence used to classify viruses as living or non-living

4. The Structure of Viruses w Viruses are non-cellular (they are not composed of cells) w Viruses are composed of four major components: Capsid/Protein Coat Nucleic Acids Specific receptors Enzymes

5. Viral Structure + function w Capsid/Protein Coat - coats or protects genetic material of virus w Nucleic Acids - either DNA or RNA which takes over and instructs a host cell on how to produce more virus. w Specific receptors or a tail - located on surface. Allows virus to attach to a specific host cell w Enzymes - Aid viral entry and/or takeover of host cell

6. Diagrams of Viruses

8. Viruses - Living or Non-living w Since viruses are non-cellular there is considerable debate about whether they are living or non -living

9. Evidence that viruses are living w Viruses contain genetic material w Viruses consist of other organic materials such as proteins w Viruses often contain enzymes that aid in replication w Viruses replicate using a host cell

10. Evidence that viruses are non-living w Viruses do not grow w Viruses are non-motile w Viruses do not respond to stimuli w Viruses are able to form crystals and survive outside of the host cell w Viruses are unable to replicate without a host cell w Viruses have no metabolic activity

11. Review w Viruses are microscopic organisms that impact all other organisms w It can be successfully debated that they are both living and non-living w Viruses have an elegantly simple structure that aids in their survival w The function of viral components relates to their structure

12. Future explorations w The specificity of virus/host relationships w Viral reproduction - the lytic and lysogenic cycles

13. Note to Dr. Potter w This is the first power point presentation that I have ever attempted w I am most proud of having figured out how to get the images of virus from the net and into my presentation w I did not fill in the notes page view because the slides provide me with a lesson plan to followS.B.