Final answer:
ADP is an allosteric activator of phosphofructokinase, promoting glycolysis and ATP production.
Step-by-step explanation:
Phosphofructokinase is a key regulatory enzyme in glycolysis. It is allosterically regulated by a number of different compounds. One of the allosteric activators of this enzyme is ADP. When ADP levels are high, phosphofructokinase is more active, promoting glycolysis and ATP production.