Arginosuccinase is

Options

A. Hydrolase
B. Ligase
C. Lyase
D. Oxido-reductase

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the classification of the enzyme argininosuccinase. We need to determine which type of enzyme it is from the given options: hydrolase, ligase, lyase, or oxidoreductase.

2. **Reviewing Enzyme Classes**:
- **Hydrolases**: These enzymes catalyze the cleavage of bonds through the addition of water (hydrolysis). They break down molecules by using water.
- **Ligases**: These enzymes are responsible for joining two substrate molecules together by forming new covalent bonds. They often require energy input, usually from ATP.
- **Lyases**: These enzymes catalyze the cleavage of bonds in a non-hydrolytic manner. They break down molecules without the involvement of water.
- **Oxidoreductases**: These enzymes facilitate oxidation-reduction reactions, involving the transfer of electrons between molecules.

3. **Analyzing Argininosuccinase**:
- Argininosuccinase specifically cleaves the molecule argininosuccinate into two products: arginine and fumarate.
- This reaction involves breaking a bond but does not involve the addition of water, which is a key characteristic of lyases.

4. **Identifying the Correct Class**:
- Since argininosuccinase breaks down argininosuccinate without using water, it fits the definition of a lyase.
- Therefore, among the options provided, argininosuccinase is classified as a lyase.

5. **Conclusion**: The correct answer is that argininosuccinase is a **lyase**.

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