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.

A Comparison Between the Dissociation of the Haemocyanins of Helix and Crustacea

1926 ◽  
Vol 4 (2) ◽  
pp. 203-214
Author(s):  
LANCELOT T. HOGBEN ◽  
KATHLEEN F. PINHEY
Keyword(s):  
Helix Pomatia ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Dissociation Curve ◽  
Hydrogen Ion Concentration ◽  
Alkaline Side ◽  
Order Of Magnitude ◽  
N Gram ◽  
Increasing Temperature ◽  
Critical Ph

1. The effect of increasing temperature upon the dissociation curve of Helix is similar qualitatively to that which has been recorded in the case of haemoglobin and crustacean haemocyanin. The value of Q per n gram molecules of oxygen is about 8000 calories. That is, it is of the same order of magnitude as the value for crustacean haemocyanin, but in all probability significantly less. 2. The effect of increase of hydrogen-ion concentration upon the haemocyanin of Helix pomatia is remarkably slight as compared with its effect on crustacean haemocyanin. At low tensions no effect is detectable. Comparing the 50 per cent. and 75 per cent. saturation points, it is seen, that, as with crustacean haemocyanin, increasing hydrogen-ion concentration at first diminishes, but beyond a certain point increases, affinity for oxygen. The curves obtained on the acid side of this point are not identical in shape with the curves obtained on the alkaline side. The significance of this fact in relation to previous observations on crustacean haemocyanin, and to Rona and Ÿllpo's experiments on haemoglobin, is discussed in the text. 3. The behaviour of the haemocyanin of Helix as compared with that of crustacean haemocyanin in relation to the presence of neutral chlorides of the alkaline and alkaline earth metals is even more different. In alkaline medium, the addition of neutral chlorides to the serum depresses the dissociation curve; at a point on the acid side of the critical pH referred to in section 2, addition of salts was not found to exert any detectable influence.

Some Observations on the Dissociation of Hæmocyanin by the Colorimetric Method

1926 ◽  
Vol 3 (3) ◽  
pp. 225-238
Author(s):  
LANCELOT T. HOGBEN
Keyword(s):  
Colorimetric Method ◽  
Hydrogen Ion ◽  
Mass Action ◽  
Ion Concentration ◽  
Effect Of Temperature ◽  
Heat Of Reaction ◽  
Dissociation Curve ◽  
Hydrogen Ion Concentration ◽  
Mass Action Law ◽  
N Gram

1. By means of the colorimetric method the effect of temperature, hydrogen ion concentration, and salinity upon the dissociation of the haæmocyanin of four species of decapod Crustacea (Maia, Cancer, Palinurus, and Homarus) has been studied. 2. Rise in temperature depresses the dissociation curve continuously between o° and 50° C. Reasons are given in favour of the conclusion that this behaviour is consonant with the applicability of the mass action law. On this understanding the heat of reaction between hæmocyanin and oxygen dissolved in the water phase in the case of Maia is of the order 9500 calories per n gram molecules of oxygen, n being defined as the least number of molecules of oxygen which can enter into the reaction. 3. In the case of all four crustaceans referred to above, the affinity for oxygen diminishes up to a point as the hydrogen ion concentration is increased : on further increasing the hydrogen ion concentration beyond a critical value for which the affinity of the serum for oxygen is minimal, the amount of oxygen taken up at low tensions increases and may surpass the values obtained for serum at normalpH. The similarity of this result with the observations of Rona and Ÿllpo on hæmoglobin is discussed. 4. On concentrating serum with neutral chlorides of the alakali and alkaline earth metals the dissociation curve is made steeper.

scholarly journals Interfacial tension and hydrogen-ion concentration

1931 ◽  
Vol 109 (760) ◽  
pp. 88-90 ◽  
Keyword(s):  
Interfacial Tension ◽  
Carboxylic Acids ◽  
Capric Acid ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Dissociation Curve ◽  
Weak Base ◽  
Hydrogen Ion Concentration ◽  
Long Chain ◽  
Hydrion Concentration

(1) Long chain carboxylic acids dissolved in benzene show regular changes in interfacial tension against aqueous "buffered" solutions as the hydrion concentration of these is altered. A fall in interfacial tension starts at p h 5·5 and extends over the range of 4·0 p h 9·3 approximately, tending to vanish at this point. The curve is not identical with a dissociation curve, though it extends over the same range of p h . For a given p h the results are identical for phosphate and glycine "buffered" solutions, and for all acids investigated, except capric acid(C 10 ), which shows an abnormality for phosphate. (2) Hexadecylamine shows similar changes, in the opposite sense between approximately the same p h range, which follow the dissociation curve of a weak base rather closely

The hydrogen-ion concentration of heavy alkaline soils

1923 ◽  
Vol 13 (3) ◽  
pp. 321-332 ◽  
Author(s):  
A. F. Joseph ◽  
F. J. Martin
Keyword(s):  
Clay Soil ◽  
Colorimetric Method ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Residual Soil ◽  
Alkaline Soil ◽  
Alkaline Soils ◽  
Soil Suspension ◽  
Hydrogen Ion Concentration ◽  
Routine Work

(1) The colorimetric method is unsuited to the examination of heavy, alkaline soils owing to the turbidity of the suspension.(2) Where the nature of the suspension permits of colorimetric determinations being made, they agree with those obtained electrometrically: with the latter method practically identical results are obtained using soil-water mixtures or moderately clear extracts.(3) No disturbing effect is likely to be introduced by amounts of nitrate up to 500 parts per million of soil.(4) Owing to the effect on the pH of a soil suspension caused by varying the proportion of water and time of extraction, these conditions should be fixed for routine work. We have found 1 hour's extraction with 5 parts of water satisfactory.(5) On account of the amphoteric or buffer nature of clay, soil shifts the reaction of acids and alkalis in the direction of neutrality.(6) The effect of sodium salts on a soil is to displace aluminium and so reduce alkalinity: the residual soil after leaching is found to be more alkaline.(7) The effect of drying alkaline soil is to cause the pH of the extract to be lower than that obtained from the undried soil. If however the time of extraction is prolonged, the differences disappear almost entirely.

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 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.

The Hydrogen Ion Concentration of the Soil and Natural Waters in relation to Diseases other than Bacterial

Parasitology ◽  
1923 ◽  
Vol 15 (2) ◽  
pp. 205-210 ◽  
Author(s):  
W. R. G. Atkins
Keyword(s):  
Natural Waters ◽  
Animal Species ◽  
Colorimetric Method ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Intermediate Hosts ◽  
Hydrogen Ion Concentration ◽  
Field Workers ◽  
Trematode Infections ◽  
Suitable Group

Certain facts are known concerning the correlation of the distribution of animal species and the hydrogen ion concentration of the soil and water. An attempt is made to apply them to the distribution of malarial fever, as illustrating insect borne disease, and to some of the numerous Trematode infections, afflicting man and other animals, in which snails act as intermediate hosts. The importance of measurements of hydrogen ion concentration (by the colorimetric method) by field workers on the distribution of animals is urged.The writer wishes to acknowledge his indebtedness to Dr M. V. Lebour for the suggestion that snails may prove a suitable group for the study of the relation between the reaction of the habitat and animal distribution.

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