Abstract Glucose 6-phosphate dependency relationships, Hill Plots, and apparent A0.5 glucose 6-phosphate values have been computed for mixtures of discrete forms of glycogen synthase. From these calculated values and by inspection of the ensuing graphs an asseessment can be made of the usefulness and limitations of I D relationships and A0.5 values as indices of the activation state of glycogen synthase in extracts of tissues subjected to various physiological stimuli.