NOVELTY - A biocompatible membrane comprises layer(s) of a synthetic polymer material and polypeptide(s). The synthetic polymer material includes block copolymer(s) and additive(s).    USE - Fuel cells useful in automotive and electronic industry.    ADVANTAGE - More stable, longer lived, more durable and able to be placed in a wider range of useful environments. It can operate when in contact with solutions having very different and very extreme pHs on either side. It can be formulated to be stable in the presence of oxidizing and/or reducing agents and is useful at extremes of temperature or other operating and storage conditions. It also facilitates the passage of current to a degree at least greater than that which would occur using the identical membrane without a polypeptide.    DETAILED DESCRIPTION - A biocompatible membrane comprises layer(s) of a synthetic polymer material having two sides and polypeptide(s) capable of participating in a chemical reaction, participating in the transporting of molecules, atoms, protons or electrons from the first side to the second side of the layer, or participating in the formation of molecular structures that facilitate the reactions or transport. The synthetic polymer material includes block copolymer(s) and additive(s).    INDEPENDENT CLAIMS are is also included for the following:    (1) a fuel cell comprising an anode compartment with anode, a cathode compartment, and the inventive biocompatible membrane disposed within the anode compartment, within the cathode compartment, or between the anode and cathode compartments; and    (2) a solution useful for producing a biocompatible membrane comprising at least one synthetic polymer material consisting of at least one block copolymer and optionally additive(s), the synthetic polymer being present in 1-30 % wt./volume, at least one polypeptide in 0.001-10 % wt./volume capable of transporting molecules,atoms, protons or electrons or participating in the formation of molecular structures that facilitate such reactions or transport, in a solvent system including both organic solvents and water.    DESCRIPTION OF DRAWING(S) - The figure shows the transfer of electrons and protons in an anode compartment of a fuel cell.