Lecture 6 



— 135 — 



Biochemical Problems 



quotient, since organic acids initially present are being 

 oxidized. 



There is one important aspect of the phenomena 

 for which our present information is deficient, a point 

 well emphasized by the investigations of Vickery and 

 his associates. A true picture of the system would 

 require that we understand not only changes in total 



25 35 

 IN DEG. C. 



Textfigure 38. — Relationship of organic 

 acid formation to respiration and to the ab- 

 sorption of potassium in excess of bromide 

 ions. (The length of the solid black column 

 and not the total height of the white plus 

 black column is equivalent to the organic acids 

 produced). (From Ulrich, 1941). 



organic acid content of the tissues, but likewise in the 

 percentages of individual acids, which may have dif- 

 ferent dissociation constants. In some cases a large 

 proportion of the total acids have to be assigned simply 

 to unknown acids. As far as the barley roots are 

 concerned, most of the organic acid content is ac- 



counted for by malic 



COOH 

 CHOH 

 CH2 

 COOH 



oxalic 



COOH 

 COOH 



and citric 



