Which of the following is maximum in chloroplast ?

Options

A. RuBP carboxylase
B. Hexokinase
C. Phosphatase
D. Nulcease

Answer

To determine which enzyme is maximum in chloroplasts, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Enzymes**: The question provides a list of enzymes. We need to analyze each one to see where they are predominantly found and their functions.

2. **Analyze Hexokinase**:
- Hexokinase is an enzyme involved in the glycolysis pathway and is primarily associated with the mitochondria, not chloroplasts. Therefore, it cannot be the answer.

3. **Analyze Nuclease**:
- Nuclease is an enzyme that breaks down nucleic acids and is primarily located in the nucleus. Thus, it is also not related to chloroplasts.

4. **Identify Chloroplast Functions**:
- Chloroplasts are the sites of photosynthesis and contain two main parts: grana (where light reactions occur) and stroma (where dark reactions occur). The stroma is rich in enzymes involved in the Calvin cycle.

5. **Analyze Rubisco**:
- The enzyme ribulose-1,5-bisphosphate carboxylase (commonly known as Rubisco) is crucial for the initial carboxylation reaction in photosynthesis. It catalyzes the fixation of carbon dioxide during the Calvin cycle, which occurs in the stroma of chloroplasts.

6. **Analyze Phosphatase**:
- Phosphatase is an enzyme that removes phosphate groups from molecules. While it may be present in chloroplasts, it is not the primary enzyme associated with photosynthesis.

7. **Conclusion**:
- Given that Rubisco is abundant in the stroma of chloroplasts and plays a vital role in photosynthesis, it is the enzyme that is maximum in chloroplasts.

### Final Answer:
The enzyme that is maximum in chloroplasts is **RUBP carboxylase (Rubisco)**.

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