Let me share with you a Comparison between Lock and Key Model and Induced Fit Model.
| Aspect | Lock and Key Model | Induced Fit Model |
| Introduction | According to this model, Substrate fits into the active site of an enzyme just like a key fits into a lock. | According to this model, Substrate induces a conformational change in the enzyme structure. |
| Fit | Substrate and active site have a complementary shape. | Initial fit may not be perfect; enzyme adjusts its shape. |
| Specificity | Highly specific; each enzyme has a unique active site. | Specific, but initial fit is less strict. |
| Enzyme Shape | Enzyme shape is rigid and does not change during catalysis. | Enzyme undergoes a conformational change upon substrate binding. |
| Binding Strength | Binding is strong and does not change during catalysis. | Initial binding is weak, strengthened during induced fit. |
| Energy Requirements | No significant energy is required for the substrate to bind. | Energy is required for the enzyme to change its shape. |
| Analogy | Like a key fitting into a lock. | Like a glove adjusting its shape to fit a hand. |
| Flexibility | Enzyme active site is inflexible. | Enzyme active site is flexible and dynamic. |
| Time Scale | Binding is rapid and specific. | Binding and catalysis may take slightly more time. |
| Examples | · Amylase
· Trypsin |
· DNA polymerase
· RIbonuclease |