The asnswer is 2DG also known as 2-Deoxy-D-glucose. 2DG is a glucose molecule that has the
2-hydroxyl group replaced by hydrogen, so that it cannot undergo further
glycolysis. As such; it acts to competitively inhibit the production of
glucose-6-phosphate from glucose at the phosphoglucoisomerase level (step 2 of
glycolysis).
