Phosphofructokinase-2 (PFK-2) is an important enzyme that plays a key role in regulating carbohydrate metabolism. It is primarily involved in the conversion of fructose-6-phosphate to fructose-2,6-bisphosphate, a molecule that activates another enzyme called phosphofructokinase-1 (PFK-1). This activation helps to promote the breakdown of glucose for energy, especially during times of high energy demand. PFK-2 is found in various tissues, including the liver and heart, and is regulated by hormones such as insulin and glucagon. These hormones help to control the levels of fructose-2,6-bisphosphate, thereby influencing the overall rate of glycolysis and gluconeogenesis. This regulation is crucial for maintaining energy balance in the body.