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AAT Bioquest

What are the advantages of induced fit model over lock and key model?

Posted January 22, 2024


Answer

The induced fit and lock-and-key model are two models that describe the interaction between enzyme and substrate. The induced fit model proposes that the enzyme’s active site is flexible and capable of changing its structural configuration to fit the substrate perfectly. The lock-and-key model proposes that the enzyme’s active site and the shape of the substrate molecule complement each other and fit together like a lock and key. If their shapes are not complementary, they are unable to bind as no structural changes take place. 

There are several advantages of the induced fit model over the lock and key model:

  • Illustrates the broad specificity of enzymes and explains how enzymes are capable of recognizing and binding to a diverse variety substrates
  • Portrays enzymes as more structurally flexible and are capable of transforming their shape to fit substrates more precisely, ensuring that enzymes can function more efficiently
  • Explains the mechanisms and possible causes of enzymatic catalysis, in particular how the conformational change induced by substrate binding stresses the bonds within the substrate, making them more reactive, which leads to more efficient catalysis
  • Prevents unwanted reactions from occurring and allows only desired reactions to occur within the cell by ensuring that enzymes remain inactive until the appropriate substrate is present  
  • Enables more precise regulation and control over metabolic pathways because enzymes can be modulated by other molecules that either enhance or inhibit their activity
  • Ensures that the enzyme-substrate complex is thermodynamically more stable than when they are separate, which allows the reaction to proceed more efficiently 
  • Minimizes the odds of wasteful or harmful side reactions by ensuring a precise fit only when the correct substrate is present
  • Facilitates multi-step reactions by allowing enzymes to undergo multiple structural changes, each optimized for a specific step in the reaction 
  • Enables enzymes to change their shapes, which offers more flexibility in evolution, allowing organisms to better adapt to evolving environments 
Additional resources

Role of Induced Fit in Enzyme Specificity: A Molecular Forward/Reverse Switch*

Enzymes

Amplite® Fluorimetric Coenzyme A Quantitation Kit *Green Fluorescence*