Metabolic Flux in Yeast Cells with Oscillatory Controlled Glycolysis

In yeast cells with oscillating glycolysis the fluctuations in metabolite concentrations are rather small compared with the total glycolytic flux. Glucose is consumed in a pulsatory manner, indicating highly efficient control at one of the first enzymatic steps. Cycling fluctuations in the apparent equilibriums constant of aldolase demonstrate this step being a retarding one and are indicative of different flow rales in the lower and in the upper part of the glycolytic sequence. Alternating phases of inhibition and activation at phosphofructokinase and glyceraldehydphosphatdehydrogenase, two steps interconnected by the retarding aldolase step and further connected by feedback in the ATP/ADP system, are considered as being the source of the observed oscillations.