12 GENERAL BIOCHEMISTRY 



American Chemical Society, was established by Ira Remsen in 1879. 

 This journal accepted articles in all fields, including agricultural and 

 physiological chemistry. Gradually, specialized scientific groups or- 

 ganized their own journals in particular fields. The literature grew 

 rapidly, and abstract journals were created to assist the busy teacher 

 and research worker in keeping abreast of the world literature. As a 

 result American biochemistry grew and flourished until today this 

 country stands second to none in this important field of science. 



NATURE OF BIOCHEMISTRY 



Biochemistry has been defined as "the chemistry of living things." 

 As a result, much of the chemistry in this book will have to do with 

 the chemistry of life processes. 



"Life" is one of the most difficult words to define, owing to the fact 

 that no one really comprehends the meaning of "the living thing." 

 However, in an attempt to approach an understanding of life we gen- 

 erally classify all things with which we are familiar into two groups, 

 the living and the non-living or lifeless. Then we proceed to justify 

 the division by listing a number of properties, all of which are com- 

 mon to the living group, but some of which are uncommon to the 

 non-living group. 



One such property possessed by all living things is autonomic move- 

 ment. To be sure, plants do not move from place to place, like ani- 

 mals, but certain plant organs are capable of movement to a limited 

 extent. Moreover, their growth is a slow movement, and considerable 

 movement takes place on an inter- and intracellular level. 



A second property, growth, is characterized by synthetic develop- 

 ment from within which is different from the type of growth we see 

 in inanimate crystals which grow by additions from the outside. A 

 third property of living matter is the power to respire. During respira- 

 tion living tissues undergo characteristic oxidative changes and lib- 

 erate energy. All living organisms possess the power of irritability; 

 that is, they respond and whenever possible adapt themselves to en- 

 vironmental stimuli. Finally, and possibly most important, living 

 organisms all possess a definite life cycle and have the power of repro- 

 duction. If it were not for the power of reproduction, all living matter 

 would cease to exist. 



All the above-mentioned properties of living matter depend on con- 

 trolled chemical reactions. These controlled reactions, in turn, depend 



