What are allosteric sites ?

Explanation

### Step-by-Step Solution

1. **Definition of Allosteric Sites**: Allosteric sites are specific regions on an enzyme that are distinct from the active site. They allow the binding of molecules that can either enhance (activate) or reduce (inhibit) the enzyme's activity.

2. **Understanding the Active Site**: The active site of an enzyme is the region where substrate molecules bind and undergo a chemical reaction. This site is crucial for the enzyme's catalytic function.

3. **Role of Allosteric Sites**: When a molecule (such as a drug) binds to an allosteric site, it induces a conformational change in the enzyme. This change can affect the shape of the active site, thereby influencing the enzyme's ability to bind to its substrate.

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