When the product formation is decreased if a substance B is added to an enzyme reaction and more substrate being added would not increase the amount of produce formed, then we assume that substance b could be a noncompetitive inhibitor. This type of inhibitor would be one that would bind to the enzyme with or without the presence of a substrate in different sites at the same time. It would change the conformation of the enzyme and also the active sites. As a result, the substrate would not be able to bind to the enzyme more effectively than the usual. The overall efficiency would decrease.
