For instance , their model could not provide answers to questions on surface tension , permeability , and the electric resistance of membranes .
Following the proposal of Gorter and Grendel , doubts inevitably arose over the veracity of having just a simple lipid bi-layer as a membrane .
Their model could not provide answers to questions on surface tension , permeability , and the electric resistance of membranes .
Following the proposal of Gorter and Grendel , doubts inevitably arose over the veracity of having just a simple lipid bi-layer as a membrane .