Answer:
Induced fit
Explanation:
Induced fit (IF) is a model used to understand enzyme-substrate interactions, which can be considered as a development of the classical lock-and-key model. This model (IF) was proposed by Daniel Koshland (1958) in order to understand protein conformational changes during the binding process. The model states that the active site of the enzyme, i.e., the region where the substrate binds and catalyzes the reaction, is reshaped when it binds with its substrate in order to improve the fit. The IF model assumes that the active site of the enzyme is flexible and is capable of changing its shape until the substrate is completely bound.