LIFE AND THE CELL 45 



namely, that of unstability. A gene can and does mutate. The virus may 

 suddenly change or mutate to a "masked" form showing no mottling, and 

 this form in turn change into another strain showing a yellow mottling in 

 place of the original light green. The size of the virus molecule increases 

 with these mutations. 



The gene to be effective must associate with other genes. It doesn't work 

 alone. A virus must be in contact with living protoplasm to be effective. Is 

 this single gene or virus molecule alive? The evidence points to the 

 answer, "No." 



Azotobacter is a heterotrophic genus of nitrogen-fixing bacteria which 

 is able to use free uncombined nitrogen of the atmosphere. It grows in 

 well-aerated arable soils; it is a strict aerobe. Azotobacter is about the size 

 of a yeast plant cell. It obtains its energy from the oxidation of carbohy- 

 drates in the soil, and takes in free nitrogen from the air for the synthesis 

 of protoplasm. Is not this a property of living organisms? 



Some Russian chemists recently carried out a very interesting experi- 

 ment. A culture of these bacteria were grown. They were then crushed 

 and their juices filtered off. There were no traces of the cell present. To 

 this filtrate a carbohydrate was added, oxygen and nitrogen gas were bub- 

 bled through the liquid. This filtrate then produced ammonia like the 

 culture of hving bacteria in the flask of nutrient broth. What was pro- 

 duciuQ" the same chemical reaction in the lifeless fluid that was carried out 

 by the living bacteria in their metabolic activities? Enzymes were no doubt 

 responsible in both chemical reactions. More ammonia was produced in 

 the test-tube than in the living culture. May not this be explained by the 

 fact that in vitro the enzymies were not shackled with the extra burden of 

 producing the characteristics of life? 



We are still at the starting line of life, and much more work will of 

 necessity have to be done before we can answer all the questions in regard 

 to the nature of genes and viruses. Can't we make the assumption that 

 the organization of matter is just a step in the production of life? Isn't it 

 a matter of complexity of organization from these simple bacteria through 

 the protozoa and metazoa to ourselves? Doesn't matter itself start from 

 protons, neutrons and electrons, combine to form atoms, and atoms to 

 form molecules, and aggregates of molecules to form crystals? 



Is not the phenomenon which we call hfe the chief difference between 

 these organizations? Somewhere and somehow in the general mixup in 

 the formation of carbohydrates, fats and proteins from simpler substances, 

 the catalyst or enzyme makes its appearance. The first catalysts may make 

 amino acids, other catalysts simple proteins from these amines, and then 

 other catalysts more complex proteins. The association of many proteins 

 to form large molecules may be the first genes. These genes arranged 

 themselves in strings to form chromosomes, specialization developed and 

 the attributes of life were exhibited. From the evidence which has been 



