Enzyme Action & Specificity
- Enzymes are specific to one particular substrate(s) as the active site of the enzyme, where the substrate attaches, is a complementary shape to the substrate
- This is because the enzyme is a protein and has a specific 3D shape
- Different types of enzymes have a different combination of amino acids in the protein, which results in a different shape
- This is known as the lock and key hypothesis
- The active site is the lock and the substrate is the key
- Only specific shaped keys can fit into each lock
The lock and key model of enzyme action diagram
The lock and key model of enzyme action results in enzyme specificity
Examiner Tip
Don't fall into the common trap of calling the enzyme and substrate the same shape. They are opposite, or complementary, shapes.
