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CHANGE OF APPARENT WEIGHT OF PLANT TISSUES IN SOLUTIONS
Author(s) -
BRIGGS G. E.
Publication year - 1970
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1970.tb02455.x
Subject(s) - chemistry , turgor pressure , sugar , osmotic pressure , permeability (electromagnetism) , urea , carbon dioxide , osmosis , weight change , diffusion , chloride , biophysics , biochemistry , thermodynamics , membrane , weight loss , biology , organic chemistry , physics , endocrinology , obesity
S ummary The effect of changes in the vacuole of the amounts of solute and of water, and of the turgor pressure, on the apparent weight of a cell and of a piece of tissue is considered. The permeability of cells in the root of carrot is estimated from the change in apparent weight of discs suspended in a solution of KNO 3 . The permeability to urea is estimated from the change in apparent weight in water after discs had equilibrated with a solution of urea. The dimensions of permeability to water and solute, and the effect of flow of water on the apparent permeability to solute, are considered. The change in apparent weight is used to measure the relatively slow uptake of cane sugar from dilute solutions of this substance. The uptake is not due to passive diffusion and the sugar absorbed appears to be osmotically active. From measurements of carbon dioxide produced and chloride ions absorbed from 0.01 M KC1 the change in apparent weight in water and change in osmotic pressure of the vacuolar sap are estimated. These are compared with the observed changes in apparent weight and changes in osmotic pressure deduced from the change in the relation between the vacuolar volume and the concentration of KC1 with which it is in equilibrium.