01/28

Virus

  • Infect all living things

  • Are they alive?

    • They don’t breathe, can’t metabolize, can’t grow, can reproduce

    • 1939 - Virus are not liquids

  • Comp

    • Nucleic acid - DNA + RNA

    • Proteins - mostly involved w/ the immune response

      • structure - capsid (Protein coat that protect NA)

      • Enzyme

      • Envelope (some don’t have) - (Helps w/ the attachment to cells)

    • Peplomers

      • Function -

        • mediate attachment (Virus to the host cell)

        • Attach to receptors (Glycoproteins attach to receptors a rbc causing cells to agglutinate

        • Enzymatic energy

        • Antigen

    • Structure of the virus

      • Shape

      • Symmetry

      • Type of capsid (all have an enveloped or non-enveloped)

        • Tubular / Helical

        • Icosahedral

        • cubic

    • 3 types of classification

      • Baltimore (7 classes)

      • -

      • -

    • Nomenclature

      • Family, Genre, Subfamilies

    • Subviral Agents

      • Satellites

      • Viroid’s

      • Prions - no Na but an infectious protein (Mad cow disease)

2nd Lecture

Replication of the Virus

Stages of Virus Replication

  • Attachemnt to the virus - Adsorption

    • Virus attaches to the receptors (some viruses dont need a receptor)

    • Ex: Hiv binds to CD4 (lymphocyte)

    • Each host cell contains 100,000

  • Penetration of virus into host cell

    • After the binding, the virus enters into the host cell

    • There are 3 ways that virus enters

      • Transfer of only the genome

      • Transport of the entire virus

      • Fusion w/ the envelope

  • Uncoating - the release if viral genome form capsid

    • Can vary from virus to virus

    • Enzymes do translate, transcribe and replicate it

  • Biosynthesis

    • Synthesis if viral proteins

    • Synthesis if viral genome

    • Early event + Late event

  • Assembly

    • Assembly of viral genome

    • Assemble of viral P

      • Creation of a mature virus

  • Release

    • Release of mature virus

    • Mechanism of virus release if various ways

      • Naked - released by cell lysis

      • Enveloped - released by budding

Antiviral Protein

  • Stop the host cell so replication cannot occur

    • Stop the binding of the receptor then the virus cannot evolve

    • Antiviral needs to be acquired during early stages, if not the virus has already replicated to much