Permeability of the Nitella internodal cell to organic substances as measured by the double chamber method

Permeability coefficients for the cell membrane of Nitella jlexilishave been determined for some organic substances by measuringtheir transcellular transport with the double chamber method.Benzyl alcohol is rapidly taken up in the vacuole of the cell.In the double chamber method benzyl alcohol taken up in thevacuole at one end of the cell is not as rapidly transportedto the other end as expected from the rate of protoplasmic streamingin the vacuole. This can be explained by assuming the presenceof a "non-streaming part" in the vacuole. The uptake of ureainto the streaming part of the cell is stimulated by directlyilluminating the part where the cell is immersed in urea solution. (Received March 10, 1971; )