Question

Which of the following correctly shows the sequence of organelles a protein would take if it were being exported from the cell?
A. ribosome-vesicle-rough ER- vesicle-golgi-apparatus-cell membrane
B. ribosome-smooth er-vesicle-cell membrane-vesicle-rough er
C. ribosome-rough er-vesicle-golgi apparatus-vesicle-cell membrane
D. smooth er-vesicle-golgi apparatus- rough er- vesicle- nucleus

Answer 1

The correct sequence of organelles a protein would take if it were being exported from the cell is:

**C. ribosome-rough ER-vesicle-golgi apparatus-vesicle-cell membrane**

Here's a brief explanation of the process:

1. **Ribosome**: Proteins are synthesized on ribosomes, which may be free in the cytoplasm or bound to the rough endoplasmic reticulum (ER).
2. **Rough ER**: If the protein is meant to be exported, it enters the rough ER for further processing and folding.
3. **Vesicle**: The protein is packaged into a vesicle that buds off from the rough ER.
4. **Golgi apparatus**: The vesicle then transports the protein to the Golgi apparatus for additional processing and sorting.
5. **Vesicle**: From the Golgi, the protein is packaged into another vesicle that carries it to the cell membrane.
6. **Cell membrane**: Finally, the vesicle fuses with the cell membrane, releasing the protein outside the cell.

Thus, option C accurately reflects this pathway.