[Campbell Biology P.211] Which statement accurately distinguishes between competitive and no... | Practice Question

Which statement accurately distinguishes between competitive and noncompetitive enzyme inhibitors Concept 8.4 ?

  • A: Competitive inhibitors bind to the allosteric site, while noncompetitive inhibitors bind to the active site.
  • B: Competitive inhibitors mimic the substrate and bind to the active site, whereas noncompetitive inhibitors bind to a different site on the enzyme, changing its shape.
  • C: Both types of inhibitors bind to the active site but affect the enzyme differently.
  • D: Noncompetitive inhibitors can be overcome by increasing substrate concentration, but competitive inhibitors cannot.

Explanation

Competitive inhibitors mimic the natural substrate and compete for the active site, thus blocking substrate binding. Noncompetitive inhibitors, on the other hand, bind to a different site on the enzyme an allosteric site , causing a conformational change that makes the active site less effective, even if substrate is bound. Due to this difference in binding, competitive inhibition can often be overcome by increasing substrate concentration, whereas noncompetitive inhibition generally cannot.