The Accumulation of Electrolytes

Abstract

It would be natural to suppose that potassium enters Valonia as KC1 since it appears in this form in the sap. We find, however, that on this basis we cannot predict the behavior of potassium in any respect. But we can readily do so if we assume that it penetrates chieflyl.2 as KOH. We may then say that under normal conditions potassium enters the cell because the ionic activity product (K) (OH) is greater outside than inside. This hypothesis leads to the following predictions:1. When the product (K) (OH) becomes greater inside (because the inside concentration of O H -rises, or the outside concentration of K + or of O H -falls) potassium should leave the cell, though sodium continues to enter. Previous experiments, 3 and those in this paper, indicate that this is the case. 2. Increasing the p H value of the sea water should increase the rate of entrance of potassium, and vice versa. This appears to be shown by the results described in the present paper.The experiments were made in Bermuda on Valonia macrophysa, Ktitz. The technique, unless otherwise stated, was that previously employed. 3 MethodsThe cells, carefully seasoned in the laboratory, were exposed to sea waters with higher and lower hydrogen ion activities than normal for periods up to 1

Changes in Hydrogen‐ion Concentration of Culture Solutions Containing Nitrate and Ammonium Nitrogen

“…But if any hydrolysis of KNO a does occur, a fall in the pH value of the solution should increase the formation of HNO a , owing to an increase in 6.5 This attempt to explain the way in which NO a or NH 4 may be absorbed in excess of oppositely charged salt ions is similar to the hypothesis of Osterhout and his coworkers that potassium enters Valonia chiefly as KOH, the rate of entrance depending on the difference between the ionic activity product [K+] X [OH-j outside and inside the plant (Jacques and Osterhout, 1934). It appears that the principles outlined above may furnish an explanation of the reaction changes shown in figures 1-3.…”

Ion transport studies and determination of the cell wall elastic modulus in the marine alga Halicystis parvula.

“…With regard to the metabolized anions, NO3-, SO4 =, and phosphate, there are only a few studies in vacuolated algae which deal with the transport of these ions. Jacques and Osterhout (21) found that NO3-was concentrated in the sap ofValonia macryophysa by 2,000-fold and in the sap of H. osterhoutii by 500-fold over the concentration in natural seawater, which is less than 10 /xM. The accumulation of phosphate and SO4 = has been shown in several species of marine algae (23,24,35).…”