Induced Fit Model
The model in which the active site changes shape on substrate binding to achieve a closer fit.
Unit
Dimensionless
In depth
Proposed by Koshland in 1958, induced fit explains why some enzymes accept a range of related substrates and how binding energy is used to strain the substrate towards its transition state. It has entirely superseded the rigid lock and key picture.
Examples in the real world
Hexokinase closing around glucose like a clam, excluding water and preventing wasteful ATP hydrolysis.