Concept: Enzymes are highly specific to their substrates, similar to how keys are specific to locks.
Mechanism
Active Site: The enzyme's active site has a specific conformation that matches the substrate.
Action: The substrate binds to the active site like a key fits into a lock, allowing the enzyme to act on the substrate and convert it into a product.
Drawbacks
Transition State: The lock and key model does not explain the transition state that occurs when the enzyme binds with its substrate.
Transition State Explanation
Importance: Understanding the transition state is crucial for explaining enzyme action.
Experimentation: Scientists used a method akin to syringes feeding solutions into a pipe to observe the reaction process in very short time intervals.
Process: Solution of enzyme and substrate are combined.
Observation: A transition state or intermediate state is formed before the substrate is converted into a product.
Evolution of the Model
1930s Discovery: With the discovery of the transition state, the lock and key model was insufficient.
Induced Fit Model: A new model was developed to better explain enzyme action, taking into account the changes in substrate conformation during the reaction.