[thedoc (OP)]

Abdulrahman asked the Naked Scientists:
   I guess the cells in human body have energy wall , this wall is first protect from enemy and invisible. I tried measuring size energy for cells by Mathematical operations and Rules of factitious , and I guess this energy wall protect cells bodies from virus because Energy difference.
What do you think?

[evan_au]

There is a field gradient which occurs across a cell wall. This gradient consists of electric voltage and ion concentrations.

The cell must do work to pump ions across the cell wall - this is most clearly seen in nerve cells, where a voltage propagates along the length of the cell, accompanied by charged ions crossing through pores in the cell wall. The cell must then do work to restore the field, ready for the next nerve impulse to come along.

The animal cell wall is often invisible under a light microscope, but it can be made visible by staining it with various chemicals.

As for viruses, they seem to be able to infect cells just fine, despite any fields that exist across the cell wall. Viruses typically have molecules in their coat which link onto molecules on the cell wall. The virus then makes a hole in the cell wall and injects its genetic instructions to take over the cell.

The body does have some defences against viruses, such as the cell committing suicide ("apotosis"), and the immune system which can detect infected cells, or destroy free-floating viruses before they infect a cell. There is no need to invoke an invisible energy wall.