Cell membrane is not permeable to

Options

A. CO
B. Glutamic acid
C. Glucose
D. Glucose 6-phosphate.

Answer

**Step-by-Step Solution:**

1. **Understanding the Cell Membrane**: The cell membrane, also known as the plasma membrane, is a biological barrier that separates the interior of the cell from the external environment. It is primarily composed of lipids (phospholipids) and proteins.

2. **Permeability of the Cell Membrane**: The cell membrane is selectively permeable, meaning it allows certain substances to pass through while blocking others. It is generally permeable to lipophilic (lipid-soluble) compounds.

3. **Hydrophilic Compounds**: The cell membrane is not permeable to hydrophilic (water-soluble) compounds. This includes substances like ions and charged molecules, which cannot easily cross the lipid bilayer.

4. **Analyzing the Options**:
- **Carbon Monoxide**: This is a small, nonpolar molecule and can diffuse through the membrane.
- **Glutamic Acid**: This is an amino acid and is hydrophilic, but it can sometimes be transported via specific transport mechanisms.
- **Glucose**: This is also a hydrophilic molecule, but it can be transported through specific glucose transporters.
- **Glucose 6-Phosphate**: This molecule has a phosphate group, which carries a negative charge, making it hydrophilic and unable to pass through the membrane freely.

5. **Conclusion**: Based on the analysis, the cell membrane is not permeable to glucose 6-phosphate due to its negative charge, which prevents it from crossing the lipid bilayer.

**Final Answer**: The cell membrane is not permeable to glucose 6-phosphate.

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