The enzyme that is not found in a `C_(3)` plant is

Options

A. RuBP Carboxylas
B. PEP Carboxylase
C. NADP reductase
D. ATP synthase

Answer

To determine the enzyme that is not found in a C3 plant, we can follow these steps:

### Step 1: Understand C3 Plants
C3 plants utilize the Calvin cycle (also known as the C3 cycle) for photosynthesis. This process involves fixing carbon dioxide from the atmosphere into organic compounds.

**Hint:** C3 plants primarily use the Calvin cycle for carbon fixation.

### Step 2: Identify Key Enzymes in the Calvin Cycle
In C3 plants, the key enzyme involved in the carbon fixation process is RuBisCO (Ribulose-1,5-bisphosphate carboxylase/oxygenase). This enzyme catalyzes the reaction between carbon dioxide and ribulose bisphosphate (RuBP).

**Hint:** RuBisCO is crucial for the initial step of carbon fixation in C3 plants.

### Step 3: Recognize Other Enzymes Present
Other enzymes present in the Calvin cycle of C3 plants include NADP reductase, which is involved in the reduction of NADP+ to NADPH, and ATP synthase, which synthesizes ATP during the light reactions of photosynthesis.

**Hint:** NADP reductase and ATP synthase are also involved in the processes of photosynthesis in C3 plants.

### Step 4: Identify the Enzyme Not Found in C3 Plants
The enzyme that is specifically not found in C3 plants is PEP carboxylase (Phosphoenolpyruvate carboxylase). This enzyme is characteristic of C4 plants, where it plays a role in the initial fixation of carbon dioxide into a 4-carbon compound.

**Hint:** PEP carboxylase is associated with C4 plants and is absent in C3 plants.

### Conclusion
The enzyme that is not found in a C3 plant is **PEP carboxylase**.