You are observing an enzyme driven reaction. You add chemical X, which inhibits the reaction. If you add more substrate, the rea
ction rate approaches the Vmax of the uninhibited reaction. Furthermore, the structure of X is similar to the natural substrate. What kind of inhibitor is X?
X is a competitive inhibitor because it fights with the substrate for the active site of the enzyme. The active site is specific for a type of substrate, but as the inhibitor has a similar structure to the substrate, it can fit and not allow the substrate to interact with the enzyme and make its reaction. What we can do to do to keep having enzyme-substrate bindings is add more substrate to the solution, so there are more substrates than inhibitors, which leads to more products as a final result of the interaction between the enzyme and the substrate.
