CHAPTER 



CARBOHYDRATE 

 METABOLIC PATHWAYS: 

 GENERAL CONSIDERATIONS 



In the two previous chapters we have discussed the 

 pecuHar metabolic events that occur in Acetobacter suh- 

 oxydans, and how some of the major carbohydrate degrada- 

 tion routes are measured in respiring organisms. In this 

 chapter I should like to strike a somewhat more general 

 note, to discuss some of the processes w^ith which most 

 students of carbohydrate metabolism are already familiar, 

 but in the hope that our fresh discussion may divert a few 

 rays of light in a new manner upon the complexities of 

 total metabolism in a whole tissue or organism. 



Let us begin this discussion by again referring to the 

 Krebs tricarboxylic acid cycle. This mechanism deserves 

 special recognition because its discovery, by Krebs and 

 Johnson almost a quarter century ago (1), ranks as one 

 of the major landmarks in all biochemistry. Its primary 

 importance to students of carbohydrate metabolism can best 



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