EULER & ADLER [1935] recently described the preparation from yeast of a cell-free enzyme, "heterophosphatese" which catalyses the transference of phosphate from (muscle) adenosinetriphosphate to glucose or fructose with the formation of a hexosephosphate. Later Meyerhof [1935] showed that preparations of hexokinase contain "heterophosphatese". The natural inference from these experiments is tha...