Question

where does fructose - 6 - phosphate bind to phosphofructokinase? at the active site, as an allosteric regulator at the active site, as a substrate at both the active site and the regulatory site, as an activator and substrate, respectively at a regulatory site, as an allosteric activator i dont know yet

Explanation:

Phosphofructokinase is an enzyme in glycolysis. Fructose - 6 - phosphate is the substrate for phosphofructokinase. Substrates bind to the active site of an enzyme. Allosteric regulators bind to sites other than the active site. Since fructose - 6 - phosphate is a substrate for this reaction (it gets phosphorylated to fructose - 1,6 - bisphosphate by phosphofructokinase), it must bind at the active site as a substrate.

Answer:

At the active site, as a substrate