. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHENOLS AND STIMULATION OF RESPIRATION 213 substances are active as the anion, [P~l] inside the cell, it was possible to determine what total concentration to employ at a given pH of solution. Thus a fairly closely graded series of concentrations could be used, which, if the assumptions were correct, should include that at which maximum respiratory stimulation is obtained. The criterion for maximum respiratory stimulation involves a point which has not been emphasized in previous work with sub- stituted phenols. With increas
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHENOLS AND STIMULATION OF RESPIRATION 213 substances are active as the anion, [P~l] inside the cell, it was possible to determine what total concentration to employ at a given pH of solution. Thus a fairly closely graded series of concentrations could be used, which, if the assumptions were correct, should include that at which maximum respiratory stimulation is obtained. The criterion for maximum respiratory stimulation involves a point which has not been emphasized in previous work with sub- stituted phenols. With increasing concentration the respiratory rate E 13 to c o. o:: control • = ;|M p-nitropheno! A= x!0'5M v= xlO'5M I 2 3 Hours FIG. 1. Rates of oxygen consumption of eggs of Strongylocentrotus purpuratiis in various concentrations of p-nitrophenol in glycylglycine-buffered sea water at pH The reagent is tipped into the egg suspension at the end of the first hour. The relative rates of oxygen consumption are given on the basis of the oxygen con- sumption during the first hour as unity. Measurements begun at 43 minutes after fertilization. Temperature = 20° C. increases, but beyond a certain concentration the increase does not remain constant with time. There is, at these higher concentrations, an initial rise in respiratory rate lasting for a short period of time followed by a steady drop in rate, which may finally reach values below that of the controls. This can be seen in Fig. 1, in which the rates of oxygen consumption in different concentrations of p-nitrophenol are plotted against time. With concentrations up to X 10~5 molar the rate rises with time as does the control (untreated eggs) rate during. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hole
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
