Induced fit model
A model for enzyme-substrate interaction to describe that only the proper substrate is capable of inducing the proper alignment of the active site that will enable the enzyme to perform its catalytic function. It suggests that the active site continues to change until the substrate is completely bound to it, at which point the final shape and charge is determined.
The induced fit model suggested by Daniel Koshland in 1958 is the more accepted model for enzyme-substrate complex than the lock-and-key model. Unlike the lock-and-key model, the induced fit model shows that enzymes are rather flexible structures in which the active site continually reshapes by its interactions with the substrate until the time the substrate is completely bound to it (which is also the point at which the final form and shape of the enzyme is determined).