ENERGY SUPPLY OF THE CELL 33 



suspension of living red blood corpuscles instantaneously 

 by adding acrolein, and observed no change of 

 temperature. 



Nevertheless, life processes depend upon a source of 

 energy. Blood corpuscles do not multiply in vitro, but 

 show distinct respiration. The energy thus produced 

 must be used for some purpose because all vital processes 

 come to a standstill if oxygen, the source of energy, is 

 excluded. 



Pfeffer (Pflanzenphysiologie II, 885) assumed that 

 the cell is like a heated engine, using up coal all the time 

 in order to be ready to supply energy the moment it is 

 wanted. It seems probable, however, that the cell is 

 more nearly comparable to an electric engine than to a 

 heat-propelled machine. This would make the simile 

 less appropriate. More probable seems the assumption 

 that energy is needed continuously to prevent, or make 

 up for, certain chemical processes which would destroy 

 the living protoplasm. Warburg (1912) believes that 

 this destruction is due largely to diffusion processes 

 while Meyerhof (1914) considers chemical processes 

 more probable. 



Meyerhof formulates his theory briefly as follows: 

 For life functions, growth and cell activity, a mixture of 

 substances within the cell must be prevented from ever 

 reaching their physical and chemical equilibrium, and 

 this cannot be done by merely slowing up the rate of 

 reaction; it requires cyclic changes to re-establish again 

 and again the continuously destroyed energy potentials. 



While we know very little about these processes, attention should 

 be called to the reduction-potential of living cells, which is discussed 

 in detail on p. 82. The maintenance of this potential requires a 

 considerable amount of energy. Since potentials of this type 

 in the cell are continuously destroyed, all the energy used for their 



