63S 



CATALASE ACTION 



K decreases because of the acidity of the peroxide. 



3 gm. of Ulva -\- 3 cc. of unneutralized peroxide, ground after washing twice in 

 distilled water, gave the following. 



K decreases because of the acidity of the peroxide. 



We could offer two explanations of this fact: (1) The distilled water 

 destroys the enzyme. (2) The enzyme migrates into the wash water. 

 To decide which hypothesis was true, we made a catalase deter- 

 mination with the wash water. We soaked 20 gm. of Ulva in 200 cc. 

 of distilled water for 40 minutes. To 4 cc. of this wash water we 

 added 3 cc. of peroxide solution. The wash water contained catalase. 



On the assumption that there is proportionality between K and 

 enzyme quantity for 3 gm. of plant, calculation gave a yield of catalase 

 of 130 X 10~^ as average K to the distilled water. W^e can say, 

 therefore, that the plant lost one-half its catalase to the surrounding 

 water. We obtain 



Washed plants: K X IC^ = 100 



Wash water = 130 



230 



Unwashed plants had a A' x 10^ of 264 which is a fairly close 

 approximation. After 1 hour and 40 minutes washing, the wash 

 water contained no more catalase than after 40 minutes. The curve 

 obtained was identical with the curve analyzed above. Wash water, 

 in which the plant remained for only 3 minutes, showed no catalytic 

 activity. 



