July 15, 1919 



Carbohydrate Metabolism in Green Sweet Corn 147 



cited, it is not necessary to determine the true velocity constants of a 

 process under different conditions if only the relative rates are desired. 

 This may be accomplished in the manner indicated in Table IV by com- 

 paring the reciprocals of the times required to do the same amount of 

 work. 



In general, it may be stated that up to 30° C. the rate of sugar loss in 

 green corn is doubled for every increase of 10°. This applies to both 

 total sugars and sucrose. It should be noted, however, that between 

 0° and 10° the temperature coefficient for sucrose is considerably greater 

 than 2. 



10 



20 



30 



40 



50 



60 



70 



24 



48 



H B S 



72 



96 



Fig. 2.— Depletion of sucrose in green Sweet com during consecutive 24-hour periods of storage, expressed 

 as percentages of the initial sucrose in the com, which was 3.87 per cent, wet weight. 



Respiration. — In a former paper the writer ^ has shown that respira- 

 tion in green sweet corn after it is first pulled from the stalk is compara- 

 tively high. During the first 24 hours of storage at 30° C. the com 

 with the husks removed respired at an average rate of 50 mgm. of carbon 

 dioxid per kgm. per hour. This rate became slower and slower until it 

 reached, in eight days, a constant rate of about 18 mgm. of carbon 

 dioxid per kgm. per hour. Respiration of course consumes sugar and 

 therefore accounts for some of the depletion of sugar in sweet com 



1 Appleman, Charles O. respiration and catalasE ACTrviTv in sweet corn. In Amer. Jour. 

 Bot., V. 5, p. 207-209, 1918. 



