|Source||University. Promotor(en): N.L. Soehngen. - Wageningen : Veenman - 81|
|Publication type||Dissertation, internally prepared|
|Keyword(s)||permeabiliteit - membranen - cytologie - saccharomyces cerevisiae - cum laude - permeability - membranes - cytology|
|Categories||Cellular Biology / Membranes|
|Abstract||Permeability of cell membranes of pressed baker's yeast was estimated by estimating the decline in concentration of the permeating substance. Therefore it was necessary to know the amount of water imbibed in the cell walls, the free water in the cells, and the imbibed water of the dispersed colloidal phase (protoplasm) in the cells.
With correction for the dispersed colloidal phase, the yeast cells behaved according to the law of Boyle Mariotte van 't Hoff. The uptake of substances by yeast cells was estimated chemically. Inorganic cations and anions were taken up according to lyotropic range, Ca 2+ < Mg 2+ < Na + < K + < NH 4+ and S0 42- < Cl - < N0 3- ,
Uptake of organic acids depended closely on their degree of dissociation. Of the sugars tested lactose did not permeate, whereas glucose was rapidly adsorbed by the cell surface. Some substances were adsorbed by the disperse phase (K + and urea).