(1) `alpha` - ketoglutaric acid `+NH_4^+ +NADPHoverset(X)rarr"glutamate"+H_2O+NADP`

What is X as shown on the arrows ?

Options

A. X - Glutamate dehydrogenase
B. X - Transaminase
C. X - Nitrogenase,
D. X - Glutamate aminase,

Answer

To solve the question regarding the enzyme X in the reaction involving alpha-ketoglutaric acid, ammonium ion, and NADPH leading to the formation of glutamate, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants and Products**:
- The reactants are alpha-ketoglutaric acid, NH4+ (ammonium ion), and NADPH.
- The products are glutamate, H2O (water), and NADP+.

2. **Understand the Reaction Type**:
- The reaction described involves the conversion of alpha-ketoglutaric acid into glutamate, which indicates a process of amination (addition of an amino group) and reduction (since NADPH is used).

3. **Recognize the Role of NADPH**:
- NADPH is a reducing agent, which suggests that this reaction involves the reduction of a carbon compound (alpha-ketoglutaric acid) to form an amino acid (glutamate).

4. **Identify the Enzyme**:
- The enzyme that catalyzes the conversion of alpha-ketoglutaric acid and ammonium ion into glutamate is known as **glutamate dehydrogenase**. This enzyme facilitates the reductive amination process, where the amino group from NH4+ is added to alpha-ketoglutaric acid.

5. **Conclusion**:
- Therefore, the enzyme X in the reaction is **glutamate dehydrogenase**.

### Final Answer:
**X = Glutamate dehydrogenase**

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