MODULATION OF SURFACE FLOW BY DIVALENT-CATIONS AND PROTONS

The flow of electrolytes and non-electrolytes through narrow pores (ab out 1 nm radius) in synthetic membranes is reported. The characteristi c features of such flow are the following. (i) The electrical conducti vity displays fluctuations typical of single channel-like openings and closings. (ii) There is selectivity between anions and cations. (iii) The electrical conductance and flow of Rb+, Cl-, deoxyglucose or wate r is inhibited by the following ions in the order H+ > Zn2+ > Ca2+ > M g2+. The similarity of the behaviour between flow through such synthet ic membranes and transport across biological membranes is noted, and i ts significance to biological phenomena is discussed.