scholarly journals Effect of salts, hydrogen-ion concentration and pure water on length of life in amoeba proteus

PROTOPLASMA ◽  
1933 ◽  
Vol 18 (1) ◽  
pp. 314-314
Keyword(s):  
Pure Water ◽  
Amoeba Proteus ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Length Of Life

Iodine Compounds and Fertilisation

1931 ◽  
Vol 8 (2) ◽  
pp. 194-201
Author(s):  
G. S. CARTER
Keyword(s):  
Chemical Structure ◽  
Sea Water ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Chemical Substances ◽  
Iodine Compounds ◽  
Free Iodine ◽  
Length Of Life ◽  
A Current

1. The presence of thyroxine in a current of sea-water in which eggs of either E. esculentus or E. miliaris are being washed prolongs the fertilisable life of the eggs. 2. Under these conditions the fertilisable life of the eggs is of approximately the same length as that of eggs which are aerated in a small quantity of sea-water. 3. Des-iodo-thyroxine and free iodine also prolong the life of eggs, when they are present in the medium, but the prolongation produced by them is much less than that produced by thyroxine. No other of several chemical substances related to thyroxine produce this effect. Changes in the hydrogen-ion concentration of the medium between pH 7.2 and 9.4 have very little effect upon the length of life of the eggs. 4. It is concluded that the component of the secretions which is essential to the activation of the egg can be replaced by thyroxine, and is therefore the same as the component which produces effects similar to those of thyroxine on the oxygen consumption of the sperm. It is also concluded that it is probable that this substance, besides being similar to thyroxine in physiological action, is related to it in chemical structure.

Memoirs: Amoeba Proteus: Some New Observations on its Nucleus, Life-history, and Culture

1924 ◽  
Vol s2-69 (273) ◽  
pp. 119-149
Author(s):  
MONICA TAYLOR
Keyword(s):  
Life History ◽  
Amoeba Proteus ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hatching Rate ◽  
Hydrogen Ion Concentration ◽  
Additional Detail ◽  
Laboratory Cultures ◽  
History Of ◽  
Chromatin Material

1. Additional detail of the minute structure of the nucleus of A. proteus has been given. 2. It has been shown that growth in the size of the nucleus and fission division of the nucleus are consequent upon a previous division of chromatin material situated in the blocks. 3. This division of the chromatin blocks has been described. 4. The history of tbe formation and development of the young Amoebae, encystment, hatching, rate of growth has been traced out. 5. Some recent modifications in the methods of making laboratory cultures of A. proteus have been recorded. 6. Amoeba culture in relation to hydrogen-ion concentration has been discussed.

Ionic Equilibria and pH

2009 ◽  
Author(s):  
Christopher O. Oriakhi
Keyword(s):  
Pure Water ◽  
Weak Acid ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ions ◽  
Hydrogen Ion Concentration ◽  
M 10 ◽  
Ionic Equilibria ◽  
Hydrated Protons ◽  
Dilute Aqueous Solution

Water is a weak acid. At 25°C, pure water ionizes to form a hydrogen ion and a hydroxide ion: H2O ⇋ H+ + OH− Hydration of the proton (hydrogen ion) to form hydroxonium ion is ignored here for simplicity. This equilibrium lies mainly to the left; that is, the ionization happens only to a slight extent. We know that 1 L of pure water contains 55.6 mol. Of this, only 10−7 mol actually ionizes into equal amounts of [H+] and [OH−], i.e., [H+] = [OH−] = 10−7M Because these concentrations are equal, pure water is neither acidic nor basic. A solution is acidic if it contains more hydrogen ions than hydroxide ions. Similarly, a solution is basic if it contains more hydroxide ions than hydrogen ions. Acidity is defined as the concentration of hydrated protons (hydrogen ions); basicity is the concentration of hydroxide ions. Pure water ionizes at 25°C to produce 10−7 M of [H+] and 10−7 M of [OH−]. The product Kw = [H+]×[OH−] = 10−7 M×10−7 M= 10−14 M is known as the ionic product of water. Note that this is simply the equilibrium expression for the dissociation of water. This equation holds for any dilute aqueous solution of acid, base, and salt. The pH of a solution is defined as the negative logarithm of the molar concentration of hydrogen ions. The lower the pH, the greater the acidity of the solution. Mathematically: pH=−log10[ H+] or −log10[H3O+] This can also be written as: pH = log10 1/[H+] or log10 1/[H3O+] Taking the antilogarithm of both sides and rearranging gives: [H+] = 10−pH This equation can be used to calculate the hydrogen ion concentration when the pH of the solution is known.

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