CHEMICAL PHENOMENA IN LIFE 



practically the influence of the viscous colloidal 

 medium in protoplasm is of very little importance 

 for ionic reactions in living cells. 



The most important substances among the 

 carbon compounds of living matter are not 

 electrolytes. Neither sugar, fatty bodies, carbo- 

 hydrates, nor protein bodies conduct the electric 

 current but to a very slight extent. All these 

 substances, then, which form the greater mass of 

 living protoplasm are non-electrolytes, and in 

 watery solution will only form a very small 

 quantity of ions or no ions at all. Most of the 

 chemical reactions which take place in assimilation, 

 digestion, and excretion are connected with such 

 non-electrolyte organic compounds. It is, therefore, 

 of interest to learn how great the velocity of such 

 reactions is in comparison with ionic reactions. 

 It is very easily shown that reactions between 

 molecular solutions are carried out comparatively 

 slowly, especially when the temperature does not 

 exceed 20 degrees. So it is when starch is trans- 

 formed into sugar, or protein into amino-acids, 

 that there is no difficulty in measuring the velocity 

 of chemical reactions. Such experimental work is 

 very important to obtain an exact theory of the 

 different chemical processes in living protoplasm. 

 We define as Reaction Velocity the quantity of the 

 substance transformed, measured in gramm mole- 

 cules per litre, which disappears in the unit of 

 time, viz. in one minute. If there is only one 

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