scholarly journals THE PERMEABILITY OF LIVING CELLS TO DYES AS AFFECTED BY HYDROGEN ION CONCENTRATION

1922 ◽  
Vol 5 (2) ◽  
pp. 223-224 ◽  
Author(s):  
Marian Irwin
Keyword(s):  
Living Cell ◽  
Quantitative Method ◽  
Living Cells ◽  
Low Ph ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Rate Of Penetration ◽  
Cresyl Blue ◽  
Ph Values

1. An accurate quantitative method of measuring the penetration of dye into the living cell is described. 2. Cresyl blue is unable to penetrate rapidly unless the pH outside the cell is decidedly greater than that inside. The rate of penetration increases with increasing pH. 3. Around pH 9 penetration of the dye is rapid while the reverse is true of exosmosis. At low pH values (5.9) exosmosis is rapid and penetration is very slow.

THE ELECTRODE POTENTIAL OF IRON IN RELATION TO HYDROGEN ION CONCENTRATION

1936 ◽  
Vol 14b (1) ◽  
pp. 31-40 ◽  
Author(s):  
J. W. Shipley ◽  
J. H. Shipley
Keyword(s):  
Electrode Potential ◽  
Chloride Ion ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Iron Electrode ◽  
General Corrosion ◽  
Citrate Buffer ◽  
Hydrogen Ion Concentration ◽  
Electrically Conducting ◽  
Ph Values

The electrode potential of iron immersed in phosphate, borate and citrate buffers of varying hydrogen ion concentration was measured, using a normal calomel electrode as the second half of the cell. Breaks in the potential of the iron electrode amounting to as much as 0.7 volts were found to occur at definite pH values for each series of buffers. The electrode exhibited an "initial" and "final" potential depending on the pH of the electrolyte and the time of immersion, the "final" value requiring several days to become established. The "final" break in the electrode potential of 0.74 volts in the pure phosphate buffer occurred between a pH of 3.1 and 4.0, that in the pure borate buffer, of 0.75 volts, occurred between a pH of 4.3 and 4.6, and in the pure citrate buffer, of 0.77 volts, between a pH of 10.1 and 10.9. The effect of chloride ion and de-aeration on the electrode potential was observed. It is suggested that the potential of the iron electrode is determined by the presence or absence of a non electrically conducting film or deposit on the iron, the formation of which is a function of the nature of the electrolyte and its hydrogen ion concentration. De-aeration apparently had no effect on the electrode potential, but the presence of chloride ion affected the establishing of the "final" potential and caused the break in voltage to appear irregularly at a much lower hydrogen ion concentration.At pH values below that at which the break in potential occurred, corrosion of the iron electrode was marked, and the electrode potential remained high, while, at pH values above the break, corrosion was virtually inhibited or confined to local spots on the electrode, and the electrode potential remained low. The presence of the chloride ion stimulated local corrosion and permitted general corrosion to proceed at a lower hydrogen ion concentration.

The Influence of Hydrogen-ion Concentration on Some Acid Resistant Bacteria

1938 ◽  
Vol 4a (3) ◽  
pp. 219-227
Author(s):  
Dennis W. Watson
Keyword(s):  
Living Cell ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Resistant Bacteria ◽  
Limited Growth ◽  
Genus Bacillus ◽  
Hydrogen Ion Concentration ◽  
Ion Concentrations ◽  
Bacillus Strains

Fifty-three strains of bacteria have been isolated from acidulated brine. They are classified into Bacillus, Micrococcus, Sarcina, and Lactobacillus. Of these the Bacillus strains failed to grow at hydrogen-ion concentrations more acid than pH 6.20, while the Micrococcus and Sarcina forms showed a greater tolerance, producing limited growth from pH 5.22 to 5.64. Other workers describing wider limits for the genus Bacillus failed to allow for the change produced in the weakly buffered environment by the living cell. The microaerophilic Lactobacilli grew at pH 3.52. These aciduric types are not actively proteolytic.

scholarly journals The Hydrogen Ion Concentration of the Cells of some Marine Algæ

1922 ◽  
Vol 12 (4) ◽  
pp. 785-788 ◽  
Author(s):  
W. R. G. Atkins
Keyword(s):  
Marine Algae ◽  
Plant Cells ◽  
Hydrogen Ion ◽  
Land Plants ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Ph Values ◽  
Optimum Ph ◽  
Acid Character

The measurements recorded for marine algæ of various groups show that the reaction of the sap is in most cases almost neutral, and in no case is the sap of the pronounced acid character met with in many land plants. This being so it follows that the enzymes concerned in the metabolism of these algæ must be quite different from those which effect corresponding changes in land plants, as may be seen on referring to the optimum pH values for various enzymes quoted in the writer's previous paper on the reaction of plant cells (1922).

Di Brom Thymol Sulhpone Phthalein as a Reagent for Determining the Hydrogen Ion Concentration of Living Cells

1922 ◽  
Vol 12 (4) ◽  
pp. 781-784 ◽  
Author(s):  
W. R. G. Atkins
Keyword(s):  
Sea Water ◽  
Living Cells ◽  
Marine Organisms ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Toxic Action ◽  
Thymol Blue ◽  
Neutral Salt ◽  
Dilute Solution ◽  
Hydrogen Ion Concentration

1. Brom thymol blue may be used in dilute solution for ascertaining the hydrogen ion concentration of certain marine organisms. It penetrates slowly, but the stained portions remain actively motile, so its toxic action does not appear to be great at the dilutions found serviceable.2. The animals studied gave values from pH6·2 to about pH7·5, though possibly the more alkaline end of the range may be pathological. About pH0·2 should be subtracted from these figures for neutral salt error. The sea water used was initially at pH8·2, corrected.

scholarly journals THE COMBINATION OF ENZYME AND SUBSTRATE

1919 ◽  
Vol 2 (2) ◽  
pp. 113-122 ◽  
Author(s):  
John H. Northrop
Keyword(s):  
Quantitative Method ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Albumin Solution ◽  
Hydrogen Ion Concentration ◽  
Egg Albumin ◽  
Insoluble Substrate

1. A quantitative method for the determination of pepsin is described depending on the change in conductivity of a digesting egg albumin solution. 2. The combination of pepsin with an insoluble substrate has been followed by this method. 3. The amount of pepsin removed from solution by a given weight of substrate is independent of the size of the particles of the substrate. 4. There is an optimum zone of hydrogen ion concentration for the combination of enzyme and substrate corresponding to the optimum for digestion. 5. It is suggested that the pepsin combines largely or entirely with the ionized protein.

scholarly journals THE EFFECT OF HYDROGEN ION CONCENTRATION ON SWELLING OF CELLS

1926 ◽  
Vol 9 (5) ◽  
pp. 709-714 ◽  
Author(s):  
Baldwin Lucke ◽  
Morton McCutcheon
Keyword(s):  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Ph Values ◽  
Wide Range

1. The effect of HCl, NaOH, CO2, and NH3 on the volume of unfertilized Arbacia eggs was tested over a wide range of pH values. 2. No swelling occurred, except in HCl solutions, and there not until after injury or death had occurred. 3. Whereas the volume of erythrocytes and of proteins such as gelatin is known to be dependent on the pH of the solution, such a relation does not exist in the case of living and uninjured cells, at least of the type tested.

scholarly journals Chemical characteristics of precipitation and hydrogen input in throughfall and stemflow under some eastern Canadian forest stands

1983 ◽  
Vol 13 (5) ◽  
pp. 948-955 ◽  
Author(s):  
M. K. Mahendrappa
Keyword(s):  
Weighted Average ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Chemical Characteristics ◽  
Weighted Mean ◽  
Hydrogen Ion Concentration ◽  
Average Value ◽  
Ph Values ◽  
Nitrate N ◽  
Forest Experiment Station

At the Acadia Forest Experiment Station (AFES) in central New Brunswick chemical characteristics of rain samples collected at five different locations were determined during the 1977–1981 period. Throughfall and stemflow samples from six softwood and three hardwood stands were collected and chemically characterized starting from the early 70's. In 1976 two of four plots in each of the stands were treated with urea at a rate of 225 kg N•ha−1. Both the quantities of rain and their pH values varied considerably between collections, months, and years. The weighted mean pH of summer (May–October) rain collected intensively during the 1977–1981 period ranged from 4.5 to 5.1, with an overall weighted average value of 4.75 for the 5 years. Sulfur and nitrate N measured during May–October 1982 amounted to 6.18 and 1.52 kg•ha−1, respectively, for the 6-month period. The concentration of hydrogen ion in the throughfall was less than that in the rain. Hardwood throughfall had lower hydrogen levels (higher pH) than the softwood throughfall. The pH of the stemflow from softwoods was lower than that of rain in most cases. Although not significantly, the hydrogen ion concentration of both throughfall and stemflow on the fertilized plots was lower than on the untreated plots. The hydrogen load of rain was reduced by all tree species, but there was considerable variation between species in their abilities to decrease total hydrogen reaching the soil.

scholarly journals THE PENETRATION OF DYES AS INFLUENCED BY HYDROGEN ION CONCENTRATION

1923 ◽  
Vol 5 (6) ◽  
pp. 727-740 ◽  
Author(s):  
Marian Irwin
Keyword(s):  
Ph Value ◽  
Gradual Increase ◽  
Ion Concentration ◽  
Active Protein ◽  
Hydrogen Ion Concentration ◽  
Brilliant Cresyl Blue ◽  
Cresyl Blue ◽  
Buffer Solutions ◽  
Ph Values ◽  
Dye Solutions

When cells of Nitella are placed in buffer solutions at pH 9, there is a very slow and gradual increase in the pH of the sap from pH 5.6 to 6.4 (when death of the cells takes place). If the living cells are placed in 0.002 per cent dye solutions of brilliant cresyl blue at different pH values (from pH 6.6 to pH 9), it is found that the rate of penetration of the dye, and the final equilibrium attained, increases with increase in pH value, which can be attributed to an increase in the active protein (or other amphoteric electrolyte) in the cell which can combine with the dye.

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