ABSORPTION AND UTILIZATION OF RADIOACTIVE CARBON DIOXIDE BY SUNFLOWER LEAVES

Abstract

Investigation of the absorption of CO2 by living sunflower leaves has shown that 4 methods of absorption are operative: solution in the water of the sap; reaction with soluble buffer substances; reaction with insoluble carbonates, presumably CaCO3; and reaction to form a noncarbonate derivative of which little is known. The CO2 absorbed previous to illumination can be used in the photosynthetic process. The absorption of C02 for photosynthetic purposes is evidently not a part of the photosynthetic reaction. The newly formed photosynthate is used up rapidly by respiration. How the rate of respiration of the newly formed photosynthate compares with the rates of respiration of other organic compounds contained within the leaf has not been detd.