Final answer:
When fructose 6-phosphate is phosphorylated by the enzyme phosphofructokinase using ATP, it yields fructose-1,6-bisphosphate, which is a key step in glycolysis and known as the committed step due to its large free energy change.
Step-by-step explanation:
Fructose 6-phosphate undergoes phosphorylation, which is a key step in the metabolic pathway known as glycolysis. This reaction is catalyzed by the enzyme phosphofructokinase, a transferase that plays a crucial role in regulating this energy-producing pathway. Consuming one molecule of ATP, phosphofructokinase adds a phosphate group to the 1 carbon position of fructose 6-phosphate, transforming it into fructose-1,6-bisphosphate (FBP). This reaction is highly regulated and can be influenced by the levels of ATP and ADP within the cell, demonstrating an example of end product inhibition. The production of FBP is known as the committed step of glycolysis due to its significant free energy change.