299 



If only the ratio of both velocity-constants be supposed to far 

 rpass unity, tin- mu-sid, diu-s o f enzyme-action will now be- fully 

 conceivable, as then- U an . ( |uilibrium between te i, Uand 



bases and the salts formed by their combination, and a- th- 

 quantities characteristic of the state of equilibrium are inversely 

 proportional to the constants of the reaction-velocities of both 

 opposite reactions. It follows that the specificity of the enzyme- 

 and ferment-action is 'really of a quantitative, rather than of a 

 qualitative nature, it being founded on an appreciable difference 

 in reaction-, or rather in decomposition-velocity of the interme- 

 diately formed combinations between the substance attacked and 

 the dissymmetrical catalysts. 



11. After all that has been done hitherto in this field of 

 research, we can therefore safely claim to have a much clearer 

 insight into the significance of the one-sided synthesis of the 

 living organism. The occurrence of optically active substances 

 during that synthesis in living bodies, finds its explanation in 

 the fact that natural synthesis can never lead to a state of 

 completed chemical equilibrium, the produced substances being 

 continuously withdrawn from and used by the organism to suit its 

 physiological needs. In connection with the fact that such chemical 

 processes commonly proceed in several stages, which cannot represent 

 states of finished equilibrium, but are only consecutive steps in 

 the whole chain of events, - - the apparent contrast between 

 natural and artificial synthesis is explained by the mere fact that 

 no highest degree of mechanical stability, and therefore no highest 

 degree of symmetry, can be expected in the synthesis performed 

 by the living organism. In natural synthesis rather a preference 

 appears for the formation of metastable intermediate products, 

 because the whole process of life is based upon the instability of 

 the conditions of the moment, and their uninterrupted change. 

 Metastable products generally act much more energetical than the 

 stable phases under the same conditions, and their assimilation will 

 therefore occur more easily and more rapidly in the physiological 

 processes of the living organism. Moreover, as soon as such a 

 lower symmetrical molecule, different from its mirror-image, has 

 once been created within the living cell, the one-sidedness of 

 further synthesis is not only fully conceivable, but it is even a 

 necessity, as we have seen above. The asymmetric synthesis can 

 no longer be considered as being the prerogative of life ; and this 



