Electrical Properties of the Plasmalemma and Tonoplast in Valonia ventricosa.

摘要: Studies were made on the electric potentials of plasmalemma ( E co ) and tonoplast vc in small cells (1-3 mm diameter) Valonia ventricosa. To measure , microelectrodes with long tapers inserted into vacuole path electrode entry off-center. The microelectrode then was pushed across cytoplasm opposite side cell. A reference placed artificial seawater bathing similar method used to except that vacuole. Both influenced by light. In light, −70 millivolts it changed −60 dark (cytoplasm-negative outside). For +86 light +69 (vacuole-positive cytoplasm). potential vo demonstrated be algebraic sum . example, means (±se) for (= ± 1) 5) is +16 millivolts, which comparable measured +17 2 millivolts. dark, 3) (+69 6) +9 value 4 external K + concentration had a controlling effect both direct current resistance plasmalemma, suggests largely diffusion potential. electrical properties affected only slightly data presented are indicative electrogenic influx pump tonoplast. It also considered possible H might electrogenically pumped from cell exterior.