What reaction occurs in Step 10 of glycolysis?

In Step 10 of glycolysis, the reaction that takes place is the conversion of phosphoenolpyruvate (PEP) and ADP to pyruvate and ATP. This step is catalyzed by the enzyme pyruvate kinase and is significant for a couple of reasons.

Firstly, it is one of the final steps in the glycolytic pathway, where the energy that has been captured during glycolysis is finally realized in the form of ATP, which is a vital energy currency of the cell. The conversion of PEP to pyruvate has a large negative free energy change, making it an energetically favorable reaction that drives the production of ATP from ADP. This step is also tightly regulated and plays a key role in ensuring that glycolysis can efficiently proceed to generate energy, particularly under anaerobic conditions.

The correct reaction aligns with the overall goal of glycolysis, which is to break down glucose and yield usable energy in the form of ATP. Each molecule of glucose metabolized through glycolysis ultimately leads to the production of two molecules of pyruvate, two molecules of ATP (net gain), and two molecules of NADH, underscoring this step's importance in cellular metabolism.