Glycolysis: Glucose Trapping and Splitting

Glycolysis begins in the cytosol, where glucose is prepared for use as energy. This process has two phases: an energy-requiring phase and an energy-releasing phase. The first phase changes glucose into a more reactive, unstable form before it can move into later steps.

In the first step, glucose ...

The energy-requiring phase is the first phase of glycolysis. As glucose enters the cell, the enzyme hexokinase transfers a phosphate group from a molecule of ATP to the 6-carbon sugar to produce glucose 6-phosphate, which becomes trapped inside the cell due to its negative charge.

Next, the enzyme phosphoglucose isomerase catalyzes the co...