Hydrogen Ion Effects on the Early Growth of Sugar beet Plants in Culture Solution

1956 ◽  
Vol 9 (3) ◽  
pp. 265-274
Author(s):  
Albert Ulrich ◽  
Kenneth Ohki
Keyword(s):  
Sugar Beet ◽  
Early Growth ◽  
Hydrogen Ion ◽  
Culture Solution ◽  
Ion Effects

Hydrogen ion effects of the vertebrate photoreceptor

1978 ◽  
Vol 188 (1) ◽  
pp. 105-113 ◽  
Author(s):  
Clark Gedney ◽  
Sanford E. Ostroy
Keyword(s):  
Hydrogen Ion ◽  
Vertebrate Photoreceptor ◽  
Ion Effects

Metabolic and respiratory hydrogen ion effects on hypoxic pulmonary vasoconstriction

1984 ◽  
Vol 57 (2) ◽  
pp. 545-550 ◽  
Author(s):  
C. Marshall ◽  
L. Lindgren ◽  
B. E. Marshall
Keyword(s):  
Pressor Response ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Respiratory Acidosis ◽  
Hydrogen Ion ◽  
Regression Equations ◽  
Rat Lung ◽  
Pulmonary Vasoconstriction ◽  
Pressor Responses ◽  
Ion Effects

Hypoxic pulmonary vasoconstriction (HPV) was studied in the ventilated-perfused rat lung in vitro. Respiratory acidosis and alkalosis were obtained by ventilating with 2, 7, or 10% CO2 (21% O2-balance N2). Metabolic acidosis and alkalosis were produced by the addition of 0.9 N NaHCO3 or 1 N lactic acid to the perfusate at constant PCO2. At each pH the pressor responses to 2 and 4% O2 were compared with the maximum pressor response (R%max) obtained with zero O2 and 5% CO2 at a normal pH (approximately 7.35). HPV was maximal when the [H+] was between 38 and 50 nM and was attenuated by changes of pH in either direction. Both respiratory and metabolic pH changes had similar effects. The combined linear regression equations were as follows: with 2% O2 the response to acidosis was R%max = 101.37 – 0.52 [H+] and to alkalosis was R%max = 2.03 [H+] - 3.85; with 4% O2 the response to acidosis was R%max = 56.88 – 0.3 [H+] and to alkalosis was R%max = 1.16 [H+] - 4.95. These effects were not due to changes of ionized calcium.

Divalent cation and hydrogen ion effects on the structure and surface activity of pulmonary surfactant

Biochemistry ◽  
1987 ◽  
Vol 26 (24) ◽  
pp. 7986-7993 ◽  
Author(s):  
Hava Efrati ◽  
Samuel Hawgood ◽  
Mary C. Williams ◽  
Keelung Hong ◽  
Bradley J. Benson
Keyword(s):  
Surface Activity ◽  
Divalent Cation ◽  
Pulmonary Surfactant ◽  
Hydrogen Ion ◽  
Ion Effects

scholarly journals THE EFFECT OF THE H ION CONCENTRATION ON THE AVAILABILITY OF IRON FOR CHLORELLA SP

1925 ◽  
Vol 9 (2) ◽  
pp. 205-210 ◽  
Author(s):  
E. F. Hopkins ◽  
F. B. Wann
Keyword(s):  
Ph Value ◽  
Maximum Growth ◽  
Chemical Precipitation ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Alkaline Solutions ◽  
Culture Solution ◽  
Hydrogen Ion Concentration ◽  
Chlorella Sp ◽  
Nutrient Solutions

The data obtained in these experiments indicate clearly that unless the necessary precautions are taken to keep the iron of the culture medium in solution the results obtained by varying the H ion concentration will not represent the true effect of this factor on growth. The availability of iron in nutrient solutions has been the subject of numerous recent investigations and it is now known that iron is precipitated at the lower hydrogen ion concentrations, that the iron of certain iron salts is less likely to be precipitated than that of others, and that certain salts of organic acids tend to keep the iron in solution. In general, ferric citrate seems to be the most favorable source of iron. In addition to chemical precipitation, however, it is also possible for the iron to be removed by adsorption on an amorphous precipitate such as calcium phosphate. As this precipitate is frequently formed when nutrient solutions are made alkaline, this may account for the discordant results reported in the literature as to the availability of certain forms of iron. By omitting calcium from the culture solution iron can be maintained in a form available for growth in alkaline solutions by the addition of sodium citrate. In such solutions the maximum growth of Chlorella occurred at pH 7.5. The alkaline limit for growth has not been established as yet. In investigating the availability of iron at varying concentrations of the hydrogen ion, changes in the pH value of the solution during the course of an experiment should also be taken into account. This is especially important in unbuffered solutions. The differential absorption of the ions of ammonium salts may cause a marked increase in the hydrogen ion concentration, which in turn will cause an increase in the solubility of iron. In strongly buffered solutions as used in these experiments this effect is slight.

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