Question

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

Explanation:

Fructose - 6 - phosphate is a substrate for phosphofructokinase. Phosphofructokinase is an enzyme in glycolysis. Substrates bind to the active site of an enzyme. Allosteric regulators bind to regulatory (allosteric) sites. Since fructose - 6 - phosphate is a substrate for the reaction catalyzed by phosphofructokinase, it binds at the active site as a substrate.

Answer:

At the active site, as a substrate