1910] APPLEMAN—CATALASE IQI 
light of Kout’s recent claims for catalase as an important enzyme 
in alcoholic fermentation, and therefore most likely in respiratory 
processes. 
SUMMARY 
can be made in the fresh extracts, if the material is ground with 
calcium carbonate, the extract diluted immediately with ten parts 
of water to one of extract, kept at 20° C. or below, and the same 
time maintained for the grinding of the potato and the catalase 
determination. 
2. An insoluble (a-catalase) and a soluble B cata form may 
be separated by ordinary filter paper. Approximately 50 per cent 
; of the total passes through. None will pass through.a Chamber- 
land-Pasteur filter. 
3. The Van’t Horr velocity coefficient for potato catalase is 
1.5 from 0° C. to 10° C. At higher ranges of temperature there 
: is an apparent progressive decrease in the velocity coefficient. 
___ This is due to’ actual destruction of the catalase, which is not due 
____ in the main to impurities in the hydrogen peroxid or to oxidation 
____ by the hydrogen peroxid. 
4. Potato catalase is not unlimited in its power to effect the 
decompgsition of hydrogen peroxid. It seems to be consumed 
in the reaction and a given amount is capable of decomposing a 
definite amount of hydrogen peroxid. 
5. The catalase activity bears a relation to the respiratory 
activities in the potato, decreasing under the same conditions as 
respiration. 
| 1. Comparable quantitative determinations of potato catalase 
| 
| 
| 
? 
I wish to acknowledge my indebtedness to Dr. WiL11aM 
CROCKER, under whose supervision this work was pursued. 
LITERATURE CITED 
I. Loew, O., Catalase. U.S. Dept. Agr., Rep. 68. 1901. 
2. Bacu, A., und Cuopat, R., Ueber den gegenwartigen Stand der Lehre 
Pflanzlichen Oxydationsfermente. Biochem. Centralbl. 1:417-421. 1903. 
3- SHAFFER, P., Some observations on the enzyme catalase. Amer. Jour. 
Physiol. 14:299. 1905. 
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