Isolated chloroplast cannot synthesize starch through dark phase inspite of possessing stroma and dark phase enzymes It is due to absence of

Options

A. Cytosol for exporting G3P
B. Photophosphorylation
C. Suitable Hydrogen acceptor
D. Carbondioxide for dark phase reactions

Answer

To solve the question "Isolated chloroplast cannot synthesize starch through dark phase in spite of possessing stroma and dark phase enzymes. It is due to absence of:", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Components of Chloroplasts**:
- Chloroplasts are the organelles in plant cells where photosynthesis occurs. They contain stroma, thylakoids, and various enzymes necessary for the light and dark reactions of photosynthesis.

2. **Identifying the Dark Phase**:
- The dark phase of photosynthesis, also known as the Calvin cycle, occurs in the stroma of chloroplasts. It involves the fixation of carbon dioxide and the synthesis of glucose from G3P (glyceraldehyde-3-phosphate).

3. **Recognizing the Role of Stroma and Enzymes**:
- The stroma provides the necessary environment for the dark reactions, and the enzymes facilitate the biochemical reactions involved in the synthesis of carbohydrates.

4. **Understanding the Limitation of Isolated Chloroplasts**:
- Isolated chloroplasts lack certain components that are essential for the complete process of photosynthesis. Although they have stroma and dark phase enzymes, they are missing critical elements that are necessary for synthesizing starch.

5. **Identifying the Missing Component**:
- The key missing component in isolated chloroplasts is the ability to perform photophosphorylation. Photophosphorylation is the process by which ATP is generated using light energy, which is crucial for providing the energy needed for the dark reactions.

6. **Conclusion**:
- Therefore, the isolated chloroplasts cannot synthesize starch despite having stroma and dark phase enzymes due to the absence of photophosphorylation.

### Final Answer:
The isolated chloroplast cannot synthesize starch through the dark phase due to the absence of photophosphorylation.