The use of two reverse enzymes acting on each side of an artificial organic membrane has permitted the realisation of artificial biomimetic membranes capable of vectorising a specific small hydrophilic molecule against its concentration gradient at constant temperature and pressure. This analogous active transport system uses chemical energy from ATP as the energy source. The experimental studies presented here show not only that this analogous transport phenomenon is ATP dependent but also that the output from this transport in terms of motes of substrate specifically vectorised per mole of ATP used can attain 100%. (C) 2004 Published by Elsevier Inc.