Refer to animation: endomembrane system. consider a protein that is targeted to be excreted to the outside of the plasma membrane. where would this protein be located in the endoplasmic reticulum?

IN THE LUMEN INSIDE OF THE ENDOPLASMIC RECTICULUM.

Explanation:

The endoplasmic recticulum is the continuous membrane system that forms that forms the more number of flattened within the cytoplasm of eukaryotic cells and performs the multiple process in the cell.

The immportant functions of endoplasmic recticulum is folding, synthesis, modification, ans transport of the protein. The lumen is the protein which is present in the endoplasmic recticulum.

The lumen of the endoplasmic recticulum is the area closed by the endoplasmic recticulum membrane, it is an extensive network of the membrane tubues, visicles, and flattened the cisternae found in the eukaryotic cells.

the answer is:

carbon dioxide