Virusesare mobile bits of genetic information encapsulatedin a protein coat. The genetic materialcan be either DNA or RNA. Once this geneticmaterial gains entry to its host cell, it takesover the host machinery for macromolecularsynthesis and subverts it to the synthesis ofviral-specific nucleic acids and proteins. Thesevirus components are then assembled intomature virus particles that are released fromthe cell. Often, this parasitic cycle of virusinfection leads to cell death and disease.