Fructose 1,6-bisphosphate is a sugar molecule that plays a crucial role in the process of glycolysis, which is how cells break down glucose to produce energy. It is formed from fructose 6-phosphate through the addition of two phosphate groups, making it a key intermediate in energy metabolism. This compound is important for regulating the flow of energy in cells. It acts as an allosteric activator for the enzyme pyruvate kinase, which helps control the rate of glycolysis. By influencing enzyme activity, fructose 1,6-bisphosphate helps ensure that cells efficiently produce the energy they need.