First glucose is phosphorylated by the enzyme hexokinase which takes a phosphate group from ATP to glucose, forming glucose-6-phosphate. Glucose-6 phosphate is then converted to its isomer, fructose-6-phosphate. Fructose-6-phosphate is phosphorylated by the enzyme phosphofructokinase using another molecule of ATP to finally form fructose-1,6-bisphosphate. The next step is the Splitting stage and finally followed by the Energy yielding stage.- ↑ Wikispaces (2015) Glycolysis. Available at: http://cellular-respiration.wikispaces.com/Glycolysis (last accessed on 3/12/15)