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Host invasion by microorganisms (view source)
Revision as of 11:13, 21 August 2008
, 11:13, 21 August 2008→[[Viruses - WikiBlood|Viruses]]
[[Image:Virus structure.jpg|thumb|right|150px|Virus Structure - B. Catchpole, RVC 2008]]
[[Image:Virus structure.jpg|thumb|right|150px|Virus Structure - B. Catchpole, RVC 2008]]
==Structure==
==Structure==
Viruses are very simple structures that do not carry any cellular machinery of their own. They depend on host cells to replicate and flourish. As such, their structure is streamlined, containing only:
*Genetic material, which consists solely of viral RNA
*Capsid proteins surrounding the RNA
*A lipid envelope
*Envelope glycoproteins (or spike proteins)
All of these elements can be recognized by the host as foreign material, and will provoke an immune response. Viruses have an advantage if they are able to penetrate host cell walls in that they are then capable of masquerading as host cells. The immune system must then counter by killing off host cells it recognizes as infected.
==Replication==
==Replication==
==Routes of infection==
==Routes of infection==