December 1 Notes

Examples of enveloped virus
HIV, Flu, and herpes family (herpes simplex I, chickenpox, STD herpes)

Glycoproteins
-Attach membrane to capsid of enveloped virus
-Glycoproteins alow env. virus to attach to host cell
-Glycoprotein = part of env. virus we have immune response against

Viral Replication
a) Attachment/adsorption
-virus bumps randonly into potential host cells in ~1:10^4 bumps virion will transiently stick to surface of host cell
-If viral surface proteins are right shape to interact with cell surface receptors, tighter junction between virion and host are formed
-If tight junction formed with virion, cell engulfs virion
-If enveloped virus, its membrane fuses with new host membrane
-If not enveloped virus, virion just engulfed by host cell, brought into cells lysosome
b) Penetration/decoating
-Lysosome of cell contains digestive enzymes, low ph, so lysosome breaks down capsid protein- this frees viral nucleic acid to be copied by host cell
-in case of complex-shaped bacteriophage, virus attaches to receptors on bacteria surface, injects DNA into bacteria, leaving capsid on outside

-Brice Buryanek

c) Enveloped viruses also have a membrane, derived from the host cell membrane
*only inject eukaryotic cells
*examples are HIV, flu, Herpes Simplex I, chicken pox
d)glycoproteins=part of envelope virus we have immune response against
*attatch membrane to capsid of the enveloped virus and allow the virus to attatch to a host cell
e) virion= single virus particle

III. Viral Replication
a) Attatchment/adsorption
-virus bumps randomly into potential host cell
-in about 1:10^4 bumps, the virion will transiently stick to the surface of the host cell
-IF viral suface proteins are the right shape to interact with the cell surface receptors, a tighter junction between virion and host cell is formed
-if a tight junction is formed with virion, the cell engulfs the virion
-if it is an enveloped virus, its membrane fuses with the new host membrane
-if it is not an enveloped virus, virion is just engulfed by the host cell and brought into the cell's lysome
b) Penetrating/Decoating
-lysosome of cell contains digestive enzymes, low pH, so lysosome breaks down capsid proteins—-this frees viral nucleic acid to be copied by the host cell
-in case of complex-shaped bacteriophage, virus attatches to receptors on bacteria surface, injects DNA into bacteria, leaving capsid on the outside

Danya Hangman

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