Which is incorrect about coenzyme ?

Options

A. Every coenzyme is a cofactor and enery cofactor is a coenzyme
B. Every coenzyme is a cofactor and every cofactor is not a coenzyme
C. Most of the coenzymes are nucleotides and are composed of vitamins
D. Coenymes are the active constituents of enzymes.

Answer

To determine which statement about coenzymes is incorrect, we need to analyze the provided options one by one.

### Step 1: Understand the Definitions
- **Cofactors** are non-protein components that assist enzymes in catalyzing reactions. They can be metal ions or organic molecules.
- **Coenzymes** are a specific type of cofactor that are organic molecules, often derived from vitamins.

### Step 2: Analyze Each Statement
1. **Every coenzyme is a cofactor**: This statement is true because coenzymes are indeed a subset of cofactors.
2. **Every cofactor is a coenzyme**: This statement is incorrect because not all cofactors are coenzymes; some are metal ions or other non-organic molecules.
3. **Most of the coenzymes are nucleotides and composed of vitamins**: This statement is generally true as many coenzymes are derived from vitamins.
4. **Coenzymes are the active constituents of enzymes**: This statement is true as coenzymes play a crucial role in enzyme activity.

### Step 3: Identify the Incorrect Statement
From the analysis, the statement that is incorrect is: **"Every cofactor is a coenzyme."**

### Conclusion
The incorrect statement about coenzymes is: **"Every cofactor is a coenzyme."**

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