n. pl. locÂ·ules or locÂ·uÂ·li (-lÄ«â²). A small cavity or compartment within an organ or part of an animal or plant, as any of the cavities within a plant ovary. [Latin.
Competitive inhibition is a form of enzyme inhibition where binding of the inhibitor to the active site on the enzyme prevents binding of the substrate and vice versa. Most competitive inhibitors function by binding reversibly to the active site of the enzyme.
Competitive inhibition occurs when the substrate and a substance resembling the substrate are both added to the enzyme. A theory called the lock-key theory of enzyme catalysts can be used to explain why inhibition occurs. The lock and key theory utilizes the concept of an active site.. The concept holds that one particular portion of the enzyme surface has a strong affinity for the substrate.