Cyanophycin granules are granules of

Options

A. Reserve carbohydrate
B. Reserve lipids
C. RuBP carboxylase
D. Reserve protein

Answer

**Step-by-Step Solution:**

1. **Understanding Cyanophycin Granules**: Begin by recognizing what cyanophycin granules are. They are granules found in certain cyanobacteria.

2. **Solubility and Accumulation**: Note that cyanophycin granules are largely insoluble under physiological conditions. This means they do not dissolve easily in the cytoplasm and are stored as granules.

3. **Conditions for Accumulation**: Understand that these granules accumulate in the cytoplasm during specific conditions, such as phosphate or sulfur starvation. This indicates that they serve a purpose in nutrient storage.

4. **Composition of Cyanophycin**: Cyanophycin is primarily composed of amino acids, particularly aspartic acid. This makes it a significant reserve for the organism.

5. **Identifying the Correct Option**: Now, evaluate the options given in the question:
- Reserve carbohydrate
- Reserve lipids
- RUBP (Ribulose bisphosphate)
- Carboxylase (an enzyme)
- Reserve protein

From the information gathered, cyanophycin granules are best classified as a reserve carbohydrate because they serve as a storage form of energy and nutrients.

6. **Conclusion**: Therefore, the correct answer to the question is that cyanophycin granules are granules of reserve carbohydrate.

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