I was on the wikipedia site reading and it said, "Some viruses do not lyse the cell but instead exit the cell via the cell membrane in a process known as exocytosis, taking a small portion of the membrane with them as a viral envelope." I thought that extrusion was an exit method used by viruses which does not immediately destroy the host bacterium. Maybe I am misunderstanding. Anyone care to clear this up for me?
Ya you are right in one sense. Lipid bi layer portion from host cell is retrived. But that doesn’t mean that viruses have lipid bi layer as there envelope. It is a small part of there envelope.
BUDDING ON HOST CELL.
Actually when virion is incorporated in bacterial or host cell it not only synthesises viral DNA copies but also proteins that are essential for making virus.
Viral envelope is made up of complex protein stucture those proteins on synthsis comes on cell membrane of host cell and at the time of exocytosis the Viral fragment(DNA/ RNA) is encorporated in it and gets separated.