Fluxes of a Nonelectrolyte and Compartmentation in Cells of Carrot Root Tissue

摘要: Permeation of thiourea into cells carrot ( Daucus carota L.) storage root discs was found to be governed by its concentration gradient only. The analysis the course efflux from preloaded shows two distinct exponential curves, apart an initial very fast component. Reasons are given for relating first part curve cytoplasm and second vacuole. rate constant through tonoplast is markedly temperature-dependent (activation energy 13.2 kcal mole − ) lowered 2,4-dinitrophenol phenyl mercuric acetate treatments. plasmalemma, on other hand, has a low activation (4.2 ), which equal that free diffusion in aqueous solution, not affected metabolic inhibitors. Possible reasons difference properties membranes discussed.