The Action of Certain Substituted Phenols on Marine Eggs in Relation to Their Dissociation

Abstract

The action of nitro- and halophenols in stimulating respiration and reversibly blocking cleavage was investigated with eggs of the sea-urchin, Strongylocentrotus purpuratus. The conc. of any one of these compounds required to produce a given effect varied with pH, as Field has shown with yeast. The variation was such as to give the same conc. of undissociated molecules at the different pH''s. Comparison of the different substituted phenols showed wide differences in the conc. of undissociated molecules required to produce the same effect. When compared on the basis of the calculated anion conc. inside the cell the different substituted phenols gave values that were fairly close (of the order of 5 X 10-6 M), picric acid and e-nitrophenol being exceptions. It is evidently the anion that is the effective agent, penetration into the cell being accomplished as the undissociated molecule.