Enzymic Reactions in Stationary Open Systems 



447 



Membrane C 



Fig. 2. Diagram of the apparatus. 



substances from vessels D and D' was about 2-2-5 nil/hr and the volume of 

 these vessels was 10 ml, the level of the liquid in these vessels being maintained 

 constant. Thus, during the course of the experiment (1-5-2 hr) the flow pro- 

 ceeded at an almost constant rate. Practically, flowing conditions were assured 

 by the fact that the components of the reaction were continually entering the 

 constant volume of the solution in cylinder A at a rate commensurable with that 

 of diffusion, while the products of the reaction, together with part of the starting 

 material, left the cylinder through membrane C. 



In each experiment the reaction in cylinder A was first studied without the 

 enzyme, then, after a stationary concentration of ascorbic acid had been estab- 

 lished for 50-60 min, AB, (cf. Fig. 3), the enzyme preparation was added and 

 its effect on the establishment of a new stationary state was studied. The addi- 

 tion of I ml of water at point B, instead of the enzyme in control experiments, 

 had no appreciable influence on the stationary concentration of ascorbic acid. 

 The addition of i ml of enzjmie solution (1-3 mg of enzyme) at point B naturally 



A 



_• •_ 



ß 

 I 



.^•— •—•—•— •- 



30 40 60 80 100 120 140 160 180 200 

 Time, min 

 Fig. 3. Enzymic oxidation of ascorbic acid (o"6%) under flowing conditions. 



