CATALYSIS AND THE ENZYMES 



normal metabolism of plants and animals. I 

 found a very interesting case of an anti-enzyme 

 in root- tips after geo tropic stimulation. This 

 anti-enzyme acts on oxidising enzymes, and is 

 able to reduce their effect considerably. Quite 

 distinct is the specific nature of anti-enzymes. 

 The anti-enzyme of geotropically stimulated roots 

 of maize does not alter the anti-enzyme effects 

 of oxidising enzymes from the bean or sunflower. 

 On the other hand, the anti-enzyme of the bean- 

 root acts on the enzyme of other leguminous plants 

 only. The specific nature of anti-enzymes is met 

 with in a similar way in the animal anti-enzymes 

 which are produced in the blood when enzymes 

 are injected into the venous system. As we have 

 already mentioned, anti-enzymes are formed under 

 such conditions, which paralyse only the enzyme 

 which was injected, and no other. 



Just as a high temperature has a great influence 

 upon the velocity of reactions catalysed by sub- 

 stances of inanimate nature, the enzyme reactions 

 are likewise considerably accelerated, when the 

 temperature is raised. Van 't HofFs Rule seems 

 to be followed even in enzymes. The reaction 

 velocity is doubled or trebled when the tem- 

 perature is raised by 10 degrees. But it is true 

 that this rule is only found for certain intervals 

 of temperature. Besides its accelerating effect 

 on the velocity of the enzyme reaction, a higher 

 temperature strongly influences the velocity of the 

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