Kingdom for Virus Where do viruses belong Are

Kingdom for Virus? Where do viruses belong?

Are Viruses Living or Non-living? Characteristics of Virus life Growth Homeostasis Metabolism Mutation Nucleic Acid Reproduction Cell

Are Viruses Living or Non-living? Characteristics of life Growth Homeostasis Metabolism Virus Cell No No No Yes Yes Mutation Nucleic Acid Reproduction Yes DNA or RNA Only with host Yes DNA Cell Divison

Viral structure: n n n Capsid: Protein Coat DNA or RNA for replication Adsorb-tion site Host specific May have a envelope

Bacteriophage n Bacteria “eating” virus n Virus uses the bacteria as a host n For viral replication

Example: Plant Peach Virus 5. Virus can infect n Plants n Fungi n Animals n Bacteria n Protists

Viral Replication n Lytic cycle n Viral DNA is injected into host cell n n Contains instructions needed to make more viruses Host cell replicates viral DNA and makes the viral capsids (protein coats) New viruses are assembled inside host cell Cell bursts open releasing new viruses

Lytic Cycle (Replication) of a Virus 1. Adsorption of virus onto the host 3. Replication of Viral DNA 4. Assembly of protein coat 2. Insertion of Virus DNA into host cell 5. Lysis of Host cell Membrane & release Of virus

Lytic Cycle

Viral Replication:

Viral Replication n Lysogenic cycle n n n Viral DNA is injected into the host cell Vial DNA inserts itself into the host’s DNA Remains inactive for days, months, or years As the cell reproduces, more cells are produced that have the viral DNA in them Eventually, the virus will enter the lytic cycle

Transduction: Viral DNA becomes inserted Into the Bacteria DNA (1/100, 000)

Lysogenic Cycle

Viruses and Human Disease

Herpes Simplex:

Warts Are a Skin Virus!

Plantar Wart

Chicken Pox & Polio Virus

Chicken Pox and Polio Virus

Rabies virus Hepatitis B (Liver)

HIV Virus

Cow Pox Vaccination 1749 n n n Acquired Immunization Artificial injection of a small amount of virus Body’s immune response makes antibodies

Emerging Viruses n Ebola