Which one of the following statements regarding mitochondrial membrane is not correct?

Options

A. the outer membrane is permeable to all kinds of molecules
B. the enzymes of the electron transfer chain are embedded in the outer membrane
C. the inner membrane is highly convoluted forming a series of infoldings
D. the outer membrane resembles a sleeve

Answer

To determine which statement regarding the mitochondrial membrane is not correct, we need to analyze the provided options based on the characteristics of the mitochondrial membranes.

### Step-by-Step Solution:

1. **Understand the Structure of Mitochondria**:
- Mitochondria have two membranes: an outer membrane and an inner membrane.

2. **Analyze the Outer Membrane**:
- The outer membrane is smooth and permeable to small molecules and ions due to the presence of porins (protein channels).
- It allows the passage of various substances, but it does not contain the enzymes of the electron transport chain.

3. **Analyze the Inner Membrane**:
- The inner membrane is highly convoluted, forming structures known as cristae.
- It is semi-permeable, meaning it selectively allows certain molecules to pass through.
- The enzymes of the electron transport chain are embedded in the inner membrane, not the outer membrane.

4. **Evaluate Each Statement**:
- **Statement A**: "The outer membrane is permeable to all kinds of molecules." - This is generally correct as it allows many small molecules to pass.
- **Statement B**: "The enzymes of the electron transfer chain are embedded in the outer membrane." - This is incorrect; they are embedded in the inner membrane.
- **Statement C**: "The inner membrane is highly convoluted forming a series of infoldings." - This is correct; the inner membrane forms cristae.
- **Statement D**: "The outer membrane resembles a sleeve." - This is also correct.

5. **Conclusion**:
- The statement that is not correct is **Statement B**: "The enzymes of the electron transfer chain are embedded in the outer membrane."

### Final Answer:
The incorrect statement regarding mitochondrial membrane is **Statement B**.

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