1 / 14

Learning Target : Virus Anatomy and Physiology

Learning Target : Virus Anatomy and Physiology. I Can … Explain how viruses infect host cells and manipulate the host cell into manufacturing more viruses. I Will … Identify the fundamental structural components of a virus List Characteristics of viruses

deron
Download Presentation

Learning Target : Virus Anatomy and Physiology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Learning Target: Virus Anatomy and Physiology I Can… Explain how viruses infect host cells and manipulate the host cell into manufacturing more viruses. I Will… • Identify the fundamental structural components of a virus • List Characteristics of viruses • Describe two common ways viruses infect host cells • Describe the two types of viral infection pathways

  2. Learning Target: Virus Anatomy and Physiology • Virus – Infectious particle made only of a nucleic acid strand (either DNA or RNA) surrounded by a protein coat • Nucleic acid • Single strand, double strand • Linear, circular or segmented • Protein coat – Capsid • Individual protein components • Different shapes • Some viruses have a lipid layer • Spikey surface protein and sugar structures • Used to attach to host cell • Can be used to identify the virus

  3. Learning Target: Virus Anatomy and Physiology

  4. Learning Target: Virus Anatomy and Physiology

  5. Learning Target: Virus Anatomy and Physiology • Viruses • Do not have ribosomes • Cannot make enzymes • Cannot make proteins • Do not carry on metabolism • Inactive outside of the host cell • Unable to reproduce without host cell • Cannot copy DNA • Viruses are NOT alive

  6. Learning Target: Virus Anatomy and Physiology • Virus shapes act lock-and-key • Can only infect certain cells • Spikes bind to cell membrane proteins • Usually species specific • e.g. Tobacco Mosaic Virus • Some viruses can cross between different species • e.g. H1N1 (Swine flu) • Some viruses start in birds • Mutate and pass to another species such as pigs • Mutate again and infect humans • Rabies virus infects all mammals

  7. Learning Target: Virus Anatomy and Physiology Two common ways viruses infect host cells • Simple Injection • Virus attaches to cell surface • Injects nucleic acid into cell’s cytoplasm • Like a syringe • e.g. T-Bacteriophage • Endocytosis • Eukaryotic cells infected • Virus fuses with the cell membrane receptors • Releases capsid into cytoplasm in vesicle • e.g. HIV Continue

  8. Learning Target: Virus Anatomy and Physiology • T-Bacteriophage infects E. coli bacteria • Simple injection method Return

  9. Learning Target: Virus Anatomy and Physiology Viral RNA uses Reverse Transcriptase enzyme to make Viral DNA genes Return

  10. Learning Target: Virus Anatomy and Physiology Once virus nucleic acid is inside host cell, 2 basic types of infection occurs • Lytic Cycle: • Virus nucleic acid takes control of host DNA • Turns on host genes to copy virus genes • Viral genes direct transcription and translation of proteins • Capsids • Enzymes • Enzymes help copy viral DNA • Host cell energy assembles viral parts • Viral enzymes dissolves host cell membrane • Destroys host cell and releases new viruses Lytic Cycle

  11. Learning Target: Virus Anatomy and Physiology • Lysogenic Cycle: Virus combines its DNA into DNA of the host cell (Recombinant DNA) • Viral DNA genes inserted into host DNA • New set of genes • Prophage in bacteria • Provirus in other organisms • New genes may change cell traits • e.g. HPV link to cervical cancer • Cell goes through mitosis • Daughter cells get identical copies of new genes • Two Paths: • Dormant and continued passing through mitosis • Activated by stress trigger • Enters Lytic Cycle and destroys cell • e.g. Herpes viral cold sore

  12. Learning Target: Virus Anatomy and Physiology Lytic Cycle or Lysogenic Cycle Return

  13. Learning Target: Virus Anatomy and Physiology • Lytic Cycle • Virus is a “Bad house guest” • Moves in • Trashes the place • Blows up the house • Leaves for new house • Lysogenic Cycle • Virus moves in • Stays and does not leave • If stressed • Trashes the place • Blows up house and leaves for new house

  14. Learning Check √: Virus Anatomy and Physiology • Name the two ways in which a virus (or virus’ DNA) can enter a cell: • __________________________ • __________________________ • What are the two viral infection cycle pathways? • _________________________ • _________________________ • 3. Why can’t you catch most viruses that infect plants or other animals.

More Related