A simple procedure based upon the principle discovered by Durr et al. (Arch. Microbiol. (1975) 105, 319-327) was used to measure the intracellular distribution of enzymes in S. cerevisiae grown under both glucose repression and derepression. No substantial hexokinase activity was found to be associated with cellular organelles. The result does not support the hypotheses that reversible binding of hexokinase to mitochondria is important in regulation of glycolysis and cell growth.