Choose the incorrect statement

Options

A. Some enzymes are named without suffix 'ase'
B. FAD can act as both coenzyme and prosthetic group
C. In IUB nomenclature , all enzymes may not provide the information of enzyme catalysis
D. Copper act as both competitive inhibitor and inorganic cofactor for cytochrome C oxidase

Answer

To solve the question of identifying the incorrect statement, we will analyze each of the provided statements step by step.

### Step 1: Analyze the First Statement
**Statement:** Some enzymes are named without the suffix "ase".

- **Explanation:** Most enzymes are named with the suffix "ase" (e.g., hexokinase). However, there are exceptions where some enzymes do not follow this naming convention. Therefore, this statement is **true**.

### Step 2: Analyze the Second Statement
**Statement:** FAD can act as both a coenzyme and a prosthetic group.

- **Explanation:** FAD (Flavin Adenine Dinucleotide) can indeed function as both a coenzyme and a prosthetic group in various biochemical reactions. Hence, this statement is also **true**.

### Step 3: Analyze the Third Statement
**Statement:** The IUB nomenclature does not provide information about enzyme catalysis.

- **Explanation:** The International Union of Biochemistry (IUB) nomenclature is designed to provide systematic names for enzymes, which often include information about the type of reaction they catalyze. Therefore, this statement is **incorrect** because the IUB nomenclature can provide information about enzyme catalysis.

### Step 4: Analyze the Fourth Statement
**Statement:** Copper acts as both a competitive inhibitor and an inorganic cofactor for cytochrome B oxidase.

- **Explanation:** Copper can function as an inorganic cofactor in enzymatic reactions and can also act as a competitive inhibitor in certain contexts. Thus, this statement is **true**.

### Conclusion
After analyzing all statements, the **incorrect statement** is the third one regarding the IUB nomenclature.

### Final Answer
The incorrect statement is: **The IUB nomenclature does not provide information about enzyme catalysis.**

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