`overset(C)overset(|)Aunderset(D)underset(|)BtoA=B+C-D`
In this reaction which of the following enzyme class should be involved ?

Options

A. Isomerases
B. Hydrolases
C. Lyases
D. Oxidoreductase

Answer

To determine the class of enzyme involved in the reaction \( A + B + C - D \rightarrow A = B + C - D \), we will analyze the components of the reaction and the nature of the changes occurring.

### Step-by-Step Solution:

1. **Identify the Reaction Type**:
- The reaction involves the transformation of substrates \( A \), \( B \), \( C \), and \( D \) into products. The presence of a double bond in the products suggests that some groups are being removed from the reactants.

2. **Understand the Role of Enzymes**:
- Enzymes are biological catalysts that accelerate chemical reactions. They are classified into different classes based on the type of reaction they catalyze.

3. **Classify the Enzyme**:
- According to the International Union of Biochemistry and Molecular Biology (IUBMB), enzymes are classified into six main classes:
1. Oxidoreductases
2. Transferases
3. Hydrolases
4. Lyases
5. Isomerases
6. Ligases

4. **Analyze the Reaction**:
- The reaction suggests that certain groups are being removed (as indicated by the terms \( C \) and \( D \)). This removal leads to the formation of a double bond between \( A \) and \( B \).

5. **Determine the Appropriate Enzyme Class**:
- The removal of groups to form a double bond is characteristic of **lyases**. Lyases catalyze the addition or removal of groups to form double bonds without the involvement of water (unlike hydrolases).

6. **Conclusion**:
- Therefore, the enzyme class involved in the reaction \( A + B + C - D \rightarrow A = B + C - D \) is **lyases** (class 4).

### Final Answer:
The enzyme class involved in the reaction is **Lyases** (Class 4).

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