Overview of Reactions of Steps 1 & 2 of Glycolysis

                                       Hexokinase
Step 1:  Glucose + ATP  ------------>  Glucose-6-Phosphate   +  ADP  +  H+
                                            <--

                                               Phosphoglucose
Step 2:  Glucose-6-Phosphate  ----------------> Fructose-6-Phosphate
                                                   isomerase