xii BIOLOGICAL CHEMISTRY 



in solutions with their application to some biological processes. 

 These must necessarily be brief and further observations 

 on the chemical reactions and physico-chemical processes 

 will be given in the other portions of the book. 



The second section deals with the accumulation of available 

 energy by the absorption of the radiant energy from the sun 

 by the green plant. It is true that the immediate products of 

 photosynthesis may be used for the formation of more 

 concentrated energy stores, but this concentration ultimately 

 depends on the energy supply from the sun. 



The third section traces the use, by plants and animals, 

 of the products of photosynthesis. This forms the largesr 

 part of the subject, as it comprises so many different processes 

 each of which can form a speciality by itself. 



In tracing the cycle of changes it is obvious that many 

 branches of chemical science are involved. Depending on 

 whether one is interested mainly in plant or animal life, one 

 or other portion assumes preponderating importance, but the 

 aim of this book is to show the relation of the parts to the 

 whole and to illustrate the various processes by the more 

 illuminating examples. 



