The aim of these notes is to contribute to the dialog between P systems
and Biological Sciences focussing on membrane proteins involved either in iron transport
inside the bacterial cells or in elimination outside the bacterial cells of substances which
are dangerous for the cell. The ability of these membrane proteins to behave as Maxwell’s
demon, gate keeper, or as “a being who can see the individual molecules” could be
important for P systems as examples of discrete processes which could be modeled by
discrete mathematics and as real molecular objects for in vitro implementation of P
systems
