1995h-983 active activebiologiclatransport adenosinetriphosphatase adenosinetriphosphatases analysis biologicaltransport biologiclatransport cell-freesystem cellfractionation cellmembranes chemistry congresses intracellularmembranes ionchannels metabolism molecularbiology organelles protons qh601c748c1986 qu136n42801995 subcellularfractions