INDUCED ENZYME FORMATION 



cell of a particular gene in its nucleus does not thereby guarantee 

 that the corresponding enzyme will be found in the cytoplasm in 

 utilizable amounts. Thus, predictive description of phenotype 

 from a knowledge of genotype alone is impossible, even at the 

 basic level of enzymatic constitution. It was necessary therefore 

 to revise such statements as "genes control enzyme synthesis" to 

 read "genes control the potentiality of enzyme synthesis." 



Whereas such theoretical implications are of great interest, 

 it was the emergent experimental consequences which proved to 

 be of greater importance. In successfully meeting the two 

 criteria mentioned above, an unequivocal demonstration was 

 provided that the induced syntliesis of specific enzymes could be 

 attained under relatively simple and controllable conditions 

 against a constant genetic background. 



It was evident that the system had been found and defined 

 which converted into experimental reality the possibility of 

 inquiring into the mechanism of enzyme synthesis. It is the 

 purpose of the present essay to summarize the information which 

 has emerged from the study from such systems. A complete 

 detailed account of the findings of the field will not be found 

 here. On the contrary, the prerogatives of the essayist have 

 been exercised to select and interpret that which is most pertinent 

 according to the writers' own peculiar bias. Those readers who 

 find themselves in agreement with both the selection and the 

 interpretation will label the result an example of good judgment 

 and analytical perception. Others will label it differently. 



The very nature of the phenomenon virtually dictates the 

 kinds of questions which are initially asked of it. The presence 

 of certain agents called inducers can, in the presence of a suitable 

 energy supply, stimulate the formation of specific enzymes. The 

 use of inducible systems to elucidate the mechanism of enzyme 

 formation resolves itself quite naturally into attempts to provide 

 adequate answers to the following questions : 



a. What is the nature of the precursor material which is 

 transformed into active enzyme molecules? 



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