Luminal and extra luminal compartments in the intracellular space of a cell distiguished by the presence of

Options

A. Mitochondria
B. Endoplasmic reticulum
C. Ribosomes
D. Cytoskeleton

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the distinction between luminal and extra-luminal compartments in the intracellular space of a cell.

2. **Identifying Key Terms**:
- **Luminal Compartment**: This refers to the space inside the membrane-bound organelles, such as the endoplasmic reticulum (ER).
- **Extra-luminal Compartment**: This refers to the space outside of these organelles within the cell.

3. **Recognizing the Role of Endoplasmic Reticulum (ER)**:
- The endoplasmic reticulum is a network of membranous tubules. It has two types:
- **Rough Endoplasmic Reticulum (RER)**: Studded with ribosomes, involved in protein synthesis.
- **Smooth Endoplasmic Reticulum (SER)**: Lacks ribosomes, involved in lipid synthesis and detoxification processes.

4. **Distinguishing Between the Compartments**:
- The ER forms a boundary that separates the luminal compartment (inside the ER) from the extra-luminal compartment (the cytoplasm surrounding the ER).
- The presence of the ER is crucial for defining these two compartments.

5. **Evaluating Other Options**:
- **Mitochondria**: Primarily involved in energy production, not specifically in distinguishing compartments.
- **Ribosomes**: Involved in protein synthesis but do not create compartments.
- **Cytoskeleton**: Provides structural support but does not define luminal and extra-luminal spaces.

6. **Conclusion**: The endoplasmic reticulum is the structure that distinguishes the luminal and extra-luminal compartments in the intracellular space of a cell.

### Final Answer:
The presence of the **endoplasmic reticulum** distinguishes the luminal and extra-luminal compartments in the intracellular space of a cell.

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