Phosphofructokinase catalyzes the first reaction in a pathway that commits the product to proceed through glycolysis, often called the first commitment step in glycolysis.Phosphofructokinase is also regulated so that the cell can quickly respond to its energy needs.Given this background information about phosphofructokinase, what is the most likely mode of inactivation of this enzyme when the cell needs to slow down or turn off glycolysis?

Question

Quizplus · Accepted Answer

Phosphofructokinase is regulated by allosteric inhibition. This means that a molecule can bind to a site on the enzyme (not the active site) and change its shape, preventing it from functioning. When a cell needs to slow down or turn off glycolysis, allosteric inhibitors such as ATP or citrate can bind to phosphofructokinase and prevent it from catalyzing the first reaction in glycolysis. This allows the cell to conserve energy and use alternative pathways for ATP production.

Phosphofructokinase Catalyzes the First Reaction in a Pathway That Commits