The Pasteur effect in carrot root tissue.

The presence of a Pasteur effect in aged discs of carrot (Daucus carota L.) storage tissue and its apparent absence in fresh discs was confirmed. Changes in the concentration of glycolytic intermediates have been determined, following the transfer of fresh and aged discs from air to nitrogen. In addition the changes in glycolytic intermediates associated with the ageing of the discs have also been measured. The results are analysed and interpreted to indicate that in aged discs the enzyme phosphofructokinase plays an important role in controlling glycolysis. In fresh discs phosphofructokinase appears to exert little control of glycolysis. The results also suggest that glycolysis may be controlled at points other than phosphofructokinase.