Nomenclature of enzyme consists of

Options

A. First substrate name and then reaction name
B. First reaction name and then product name
C. Only product name.
D. Only reaction name.

Answer

### Step-by-Step Solution:

1. **Understanding Enzyme Nomenclature**: Enzyme nomenclature is the system used to name enzymes based on their function and the substrates they act upon. The International Union of Biochemistry and Molecular Biology (IUBMB) has established guidelines for this nomenclature.

2. **Components of Enzyme Nomenclature**: According to the IUBMB, the nomenclature of an enzyme consists of two main components:
- **Substrate Name**: This is the name of the molecule that the enzyme acts upon. It is the substance that undergoes a chemical change.
- **Reaction Type**: This describes the type of reaction that the enzyme catalyzes. It indicates the biochemical process that occurs.

3. **Example of Enzyme Nomenclature**: A classic example is "pyruvate dehydrogenase":
- **Substrate**: Pyruvate (the substrate that the enzyme acts on).
- **Reaction Type**: Dehydrogenase (indicating that the enzyme catalyzes an oxidation-reduction reaction).

4. **Conclusion**: Therefore, the correct format for enzyme nomenclature is to first mention the substrate followed by the type of reaction the enzyme catalyzes.

### Summary:
The nomenclature of enzymes consists of the substrate name followed by the reaction type, as defined by the International Union of Biochemistry.

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