ENERGY SUPPLY OF THE CELL 



23 



From this, we must conclude that energy liberated 

 by one cell cannot be utilized by other cells, and that 

 even in tissues, neighboring cells have no means of 

 exchanging any surplus energy directly. It follows 

 further that the chemical energy must be liberated 

 within the cell, for if it were liberated outside, it would 

 have to assume one of the forms mentioned above (heat 

 most probably, or eventually light or electricity) which 

 cannot be utilized by the cells. Whether the mitogenetic 

 rays (Gurwitsch, 1929) act merely as stimulants, or 

 whether their energy can be actually utilized is entirely 

 unknown. 



This must be kept in mind with bacteria acting upon 

 insoluble food. Only that part of the energy becomes 

 available which is produced in the cell; the energy 

 liberated outside of the cell merely raises the temperature 

 of the medium, without any further benefit to the 

 organism. 



Table 5. — Energy Liberated by Enzymes from 1 Gm. of Substrate 



Since only that part of the food, which is decomposed 

 in the cell is of benefit to the bacterium, it is essential 

 that the food pass through the plasma membrane. 

 The compounds need not necessarily be water-soluble 

 to accomplish this; a lipoid-soluble compound might 



