The view that active site of an enzyme is flexible and when a substrate combines with it, cause changes in enzyme structure is known as:

Explanation

The induced fit model is the correct answer. It proposes that the active site of an enzyme is not a rigid structure. Instead, it is flexible and undergoes conformational changes when the substrate binds to it, ensuring a snug fit that enhances the enzyme's ability to catalyze the reaction effectively. This contrasts with the lock and key model, which views the active site as a rigid, unchanging structure. The sliding filament model is unrelated as it pertains to muscle contraction mechanisms, and the specificity model emphasizes enzyme-substrate selectivity without addressing structural changes in the enzyme.