New Unit Microbiology Viruses Micro small biology study

New Unit Microbiology - Viruses 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 w

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

The Structure of 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 w

Viral Structure + function 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 w

Diagrams of Viruses

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

Evidence that viruses are living 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 w

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

Review 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 w

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