scholarly journals STIMULATION BY HYDROCHLORIC ACID IN THE CATFISH, SCHILBEODES

1931 ◽  
Vol 15 (2) ◽  
pp. 119-124 ◽  
Author(s):  
William H. Cole ◽  
James B. Allison
Keyword(s):  
Reaction Time ◽  
Hydrochloric Acid ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Acid Molecule ◽  
Experimental Conditions ◽  
Hydrogen Ion Concentration ◽  
Effective Stimulus ◽  
Wide Range ◽  
Increasing Function

1. The reaction of the catfish, Schilbeodes gyrinus Mitchill, to hydrochloric acid over a wide range of concentrations (from pH 1.82 to pH 6.83) has been studied under experimental conditions which reduced to a minimum all other stimuli. 2. As the [H+J increases within the limits mentioned, the reaction time of the fish decreases. In other words, the rate of the stimulation processes is an increasing function of the hydrogen ion concentration. 3. The effective stimulus is the hydrogen ion, since NaCl solutions of equivalent concentration were not stimulating. 4. Stimulation by hydrochloric acid is therefore correlated with the potential of the cation resulting from dissociation of the acid molecule.

scholarly journals A Colorimetric Method for Studying the Dissociation of Oxyhæmocyanin suitable for Class Work

1925 ◽  
Vol 13 (4) ◽  
pp. 970-980 ◽  
Author(s):  
C. F. A. Pantin ◽  
Lancelot T. Hogben
Keyword(s):  
Marked Effect ◽  
Colorimetric Method ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Dissociation Curve ◽  
Hydrogen Ion Concentration ◽  
Laboratory Class ◽  
Wide Range ◽  
Increasing Temperature ◽  
Limits Of Error

1. A simple colorimetric method for plotting the dissociation curve of haemocyanin is indicated. The limits of error are within 5 per cent. The simplicity of the method commends it for laboratory class work.2. The effect of hydrogen ion concentration on the dissociation of the hsemocyanins of the crustacean Palinurus and the pulmonate Helix have been compared. In the snail change of hydrogen ion concentration over a wide range was not found to affect the dissociation of the hsemocyanin: in 'the crustacean there is a marked effect similar to that seen in the dissociation of hæmoglobin.3. The similarity of crustacean hsemocyanin to haemoglobin is also seen in that increasing temperature depresses the dissociation curve. The effects of certain salts upon haemocyanin. have also been recorded.

Nutritional studies of a flagellated protozoan Hexamita inflata from the Canadian oyster, Crassostrea virginica

1968 ◽  
Vol 14 (8) ◽  
pp. 817-821 ◽  
Author(s):  
B. T. Khouw ◽  
H. D. McCurdy Jr.
Keyword(s):  
Unsaturated Fatty Acids ◽  
Egg Yolk ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Wide Range ◽  
Simple Medium ◽  
Nutritional Studies ◽  
Vitamin Mixture ◽  
Anaerobic Environment

The physical and nutritional requirements for growth of Hexamita inflata have been studied in axenic cultures. The flagellate was capable of growing over a wide range of temperature (5 °C to 25 °C), of hydrogen ion concentration (pH 4.5 to 8.5), and of salinity (3 to 28‰); and required a reducing or anaerobic environment. The requirement of an egg-yolk suspension for growth was partially satisfied by unsaturated fatty acids. Attempts to replace the peptone by mixtures of amino acids were not successful. A simple medium containing a vitamin mixture, linoleic acid, glucose, cysteine, peptone, and salt has been formulated.

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 A STUDY OF THE ACTION OF ACID AND ALKALI ON GLUTEN

1919 ◽  
Vol 1 (4) ◽  
pp. 459-472 ◽  
Author(s):  
L. J. Henderson ◽  
Edwin J. Cohn ◽  
P. H. Cathcart ◽  
J. D. Wachman ◽  
W. O. Fenn
Keyword(s):  
Electrical Conductivity ◽  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Acid Base ◽  
Secondary Importance ◽  
Hydrogen Ion Concentration ◽  
Acid Base Equilibrium ◽  
Simple Chemical

In this paper there are reported studies of the acid-base equilibrium in systems containing gluten suspended in solution of hydrochloric acid and sodium hydroxide. The studies have involved measurements of the hydrogen ion concentration, of the electrical conductivity, and of the solution of the proteins. Further, measurements have been made of the swelling and of the viscosity of the gluten component of such systems. The results seem to show that simple chemical phenomena are most important in such systems, and that the modifications of these, resulting from colloidal and heterogeneous characteristics, are of secondary importance in determining the condition of equilibrium, though somewhat more significant in the progress of the system toward the condition of equilibrium.

Effect of acute changes in the PaCO2 on acid–base parameters in normal dogs and dogs with metabolic acidosis or alkalosis

1983 ◽  
Vol 61 (2) ◽  
pp. 166-173 ◽  
Author(s):  
M. Bercovici ◽  
C. B. Chen ◽  
M. B. Goldstein ◽  
B. J. Steinbaugh ◽  
M. L. Halperin
Keyword(s):  
Metabolic Acidosis ◽  
Linear Relationship ◽  
Regression Line ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Gastrointestinal Fluid ◽  
Wide Range ◽  
State Formula ◽  
Acute Changes

There is a linear relationship between the [Formula: see text] and blood hydrogen ion concentration in normal dogs, but for theoretical reasons to be discussed, we questioned whether this relationship would apply in animals with metabolic acidosis or alkalosis. To study this in more detail, animals were divided into three groups: normal, metabolically acidotic, and metabolically alkalotic. Following anesthesia and bilateral ureteral ligation, dogs were intubated and ventilated to produce acute steady-state [Formula: see text] values corresponding to the range observed during disease states. Changes in the volume and electrolyte composition of the gastrointestinal fluid and urine as well as the concentration and distribution of lactate were evaluated in all experiments. We observed the previously described linear relationship between the [Formula: see text] and blood hydrogen ion concentration in normal dogs, but the slope of the regression line differed significantly from those of dogs with metabolic acidosis and metabolic alkalosis. On the other hand, there was a consistent relationship between the ratio of the [Formula: see text] values, but not the absolute [Formula: see text], and the change in the plasma bicarbonate concentration over a wide range of [Formula: see text] values in all groups of dogs. The chemical basis for these observations will be discussed.

Studies on Azotobacter in Malayan soils

1936 ◽  
Vol 26 (2) ◽  
pp. 268-280 ◽  
Author(s):  
R. A. Altson
Keyword(s):  
Calcium Carbonate ◽  
Calcium Chloride ◽  
Culture Medium ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Lag Phase ◽  
Hydrogen Ion Concentration ◽  
Factors Associated ◽  
Wide Range

These observations have shown that the strains of Azotobacter occurring in certain Malayan soils are unable to initiate growth on standard media, except after a lag phase of considerable duration. Evidence has been obtained which suggests that this inability is not necessarily an indication of a scarcity of the organisms in the soil used as an inoculum, but may be due to factors associated with the composition of the culture medium.In particular the strains of Azotobacter developing from these soils are checked by the presence of calcium carbonate in the medium. They will grow well in a medium in which calcium chloride replaces calcium carbonate, but equally well where the medium contains but traces of calcium.These strains can tolerate a wide range of hydrogen-ion concentration extending on the acid side to pH. 3·6. Their existence invalidates the use for these soils of all such microbiological tests of lime requirement as make use of Azotobacter as indicator.

scholarly journals The Hydrogen Ion Concentration of Sea Water in its Biological Relations

1922 ◽  
Vol 12 (4) ◽  
pp. 717-771 ◽  
Author(s):  
W. R. G. Atkins
Keyword(s):  
Carbon Dioxide ◽  
Methyl Orange ◽  
Hydrochloric Acid ◽  
River Water ◽  
Sea Water ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Acid Water ◽  
End Points ◽  
Hydrogen Ion Concentration

It has long been known that sea water is alkaline and numerous determinations of its alkalinity have been made. The method adopted was the usual one for mixtures of carbonates and bicarbonates, or some modification of it. Those waters which give no colour with phenolphthalein contain bicarbonate only, but for the most part ocean waters have a small amount of carbonate also. Owing to the presence of larger amounts of carbonates and bicarbonates the reaction of sea water is more stable than that of rain or river water, inasmuch as it has a greater alkaline reserve which acts as a “buffer.” The significance of this has been pointed out by Moore, Prideaux, and Herdman (1915) and by other workers. The measurement of alkalinity was carried out by the above named using N/100 hydrochloric acid and titrating to the end points with phenol phthalein and methyl orange. The results are recorded in cubic centimetres of centinormal acid per 100 c.c. of sea water; this is convenient as it is what is measured directly, but others adopt the perhaps more rational notation of milligram equivalents of hydroxyl per litre (Buch, 1914). One cubic centimetre of N/100 acid per 100 c.c. corresponds to 0.1 milligram equivalent per litre. Some workers on fresh waters, Birge and Juday (1911) for example, consider water as acid if it contains more carbon dioxide than that sufficient to convert the carbonate into bicarbonate, and titrate back to a pink with phenolphthalein. Their acid water is, however, still alkaline to methyl orange.

scholarly journals THE BACTERICIDAL ACTION OF HUMAN SERUM ON HEMOLYTIC STREPTOCOCCI

1937 ◽  
Vol 66 (5) ◽  
pp. 617-636 ◽  
Author(s):  
William S. Tillett ◽  
C. Chester Stock
Keyword(s):  
Hydrogen Ion ◽  
Ion Concentration ◽  
Sodium Ascorbate ◽  
Experimental Conditions ◽  
Hydrogen Ion Concentration ◽  
Oxidation Reduction ◽  
Constant Ph ◽  
Highly Sensitive ◽  
Destructive Action ◽  
Killing Action

Aerobic Tests. Changes in pH Which Occurred during Incubation.—(a) The pH of sterile specimens of both normal and patients' sera increased, during 24 hours incubation, from 8.0–8.8 up to 9.2–9.6. (b) The pH of patients' sera, inoculated with hemolytic streptococci, progressed in the alkaline direction as did the sterile specimens. (c) The pH of normal sera, inoculated with hemolytic streptococci, pursued a variable course at lower levels than the sterile specimens. The differences in the changes in pH which occurred in streptococcidal sera and in normal controls were dependent upon and secondary to the presence or absence of killing action in the specimens. Aerobic Tests. Effect of Different Levels of Hydrogen Ion Concentration, Adjusted at Beginning of Experiment, but Uncontrolled during Period of Incubation.—(a) The streptococcidal activity of patients' sera was inactivated when the hydrogen ion concentration of the specimens was adjusted to levels ranging from 6.4 to 7.4. The inactivation of highly potent samples of sera required a greater reduction in pH than did specimens of moderate killing activity. (b) Normal sera, adjusted to pH 9.2 or higher, exhibited a relatively slowly acting bactericidal process, which seemed to represent the toxic effect of alkalinity. Aerobic Tests. Effect of Glutathione and Sodium Ascorbate.—The streptococcidal action of patients' sera was markedly impaired by the addition of reducing agents. The inactivation was, in general, comparable to that previously obtained under conditions of anaerobiosis. The results, suggesting that some factor pertaining to biological oxidation-reduction may influence the streptococcidal action of sera, have been discussed. Tests Performed in Closed Jars by Means of Which Relatively Constant pH Was Maintained during the Period of Incubation.—Under the experimental conditions which were employed, the effectiveness of the streptococcidal action of patients' sera was maintained only in alkaline ranges. The most potent specimens of sera were active at lower levels of pH (7.9–8.2) than were other samples (8.4–8.8). All of the observations reported in this article were made with a strain of hemolytic streptococcus of the beta type, which is highly sensitive to the destructive action of serum from acutely ill patients.

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