Viruses - derived from the membrane of the cell the virus infects and is picked up on the way out It has peplomers(spikes derived from virus

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Viruses: Look at the viruses on the above, in particular polio virus. It has the icosohedral shape with 20 triangles. And each triange is composed of 3 proteins(trangulation number = 3). This is very efficient allowing the entire coat to be composed of 3 proteins, saving space for polio's RNA. Helical viruses appear as if they were a tube but really they are helixal. A circle of proteins 1-7 make a ring, then similar rings are stacked up. Once again this economizes in the amount of genetic material the virus has to lug around. Encapsulated viruses have a lipoprotein envelope that surrounds the capsid. The capsid can be icosohedral (as in HIV) or another shape. Much of the capsid material is
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Unformatted text preview: derived from the membrane of the cell the virus infects and is picked up on the way out. It has peplomers (spikes) derived from virus genetic material and on the surface are proteins which allow for attachment of the virus to the host cell. Viral Life Cycles: There are several steps in the life cycle of a virus: Attachment: The virus must contact a homologous protein on the surface of the cell. Attachment involves recognition of virus surface proteins with cell surface proteins. The virus requires a receptor. Often the lack of a receptor can explain why viruses are specific to a cell type or species....
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This note was uploaded on 01/23/2012 for the course MCB MCB2010 taught by Professor Smith during the Fall '09 term at Broward College.

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