THE ENERGETICS OF ORGANISMS 93 



This energy is coupled with the system CO., OH 2 and so the 

 formation of formaldehyde occurs. In the latter reaction two 

 things are involved, (i) the possibility of the combination of 

 CO 2 and OH 2 and (2) the available energy supplied by the 

 degrading solar radiation. So we have the conspicuously 

 endothermic reaction : 



(i) CO2 + OH2 = H.CHO+O2 



Reactants that Resultants that 



have no available have much available 



energy energy 



and the process — 



(2) Solar radiation _ solar radiation available 



of high frequency of low frequency energy. 



The available energy represented in the right-hand side of 

 the second equation accounts for the fact that the resultants in 

 the first equation have more available energy than had the 

 reactants. In their formation entropy locally decreases. 



In analogous ways nitrogen-assimilation occurs in plants. 



35^. Anabolic and Katabolic Processes. These plant 

 assimilations are called anabolic processes. But in all plants 

 other processes leading to mechanical effects, etc., occur. Thus 

 a tree raises matter (its own substance) into the air against gravity ; 

 its parts move, flowers may open or shut ; roots and tendrils 

 move, climb, etc. ; water (the sap) is circulated ; transpiration 

 of water occurs ; oxidations occur, etc. In these processes 

 energy, in the available form, is expended and degrades. Their 

 energy comes from reactions of the form 



C + O2 = CO2 _, available 



reactants resultant energy. 



And the available energy so set free makes possible the effects 

 mentioned. These latter processes are called katabolic ones. 

 In them energy degrades and entropy increases. 



But in plants, in general, the anabolic processes are greatly 

 in excess of the katabolic ones. So in plants, in general, entropy 

 locally increases. Regarding plants as parts of the universe we 

 conclude that their effect is to retard entropy -growth by preventing 

 the complete dissipation of solar energy. The general results 

 of their activities is that available energy in the forms of plant 



