Question

competitive inhibition occurs when another molecule, similar in shape and chemical properties to the substrate, binds to the active site of an enzyme. this binding blocks the substrate from accessing the active site, preventing the enzyme from catalyzing the reaction. also, noncompetitive inhibition is performed by an allosteric inhibitor binding to the allosteric site on an enzyme. this changes the conformation, or shape, of the enzyme and prevents the substrate from binding to the active site. this allows cells to conserve energy and prevent unnecessary reactions from occurring. image of competitive inhibition and noncompetitive inhibition diagrams during competitive inhibition, where does the competing molecule bind? - the allosteric site - the sympatric site - the active site

Explanation:

The text defines competitive inhibition as a molecule (competitive inhibitor) similar to the substrate binding to the enzyme's active site, blocking the substrate. The options: allosteric site is for noncompetitive inhibition (from the text), "sympatric site" is not a relevant term here. So the competing molecule in competitive inhibition binds to the active site.

Answer:

the active site