how does the endomembrane system work with the ribosomes in a cell?

Question

anonymous · Answer

The endomembrane system consists of vast network of membranes that include the nuclear envelope, the endoplasmic reticulum, the golgi apparatus, lysosomes, vacuoles, vesicles, endosomes and the cell membrane. 
We know that all proteins are synthesized on ribosomes in the cytosol, but some of these proteins are required in certain organelles or to be exported from the cell (ie. hormones) in this case the protein contains a special "tag" which allows it to dock on components of the endomembrane system, usually the endoplasmic reticulum or ER. Then the protein is modified in the ER and Golgi apparatus and final transported to specific organelles or exported from the cell. 
So, to clarify, proteins needed in specific organelles or for export are synthesized on ribosomes and then dock on the ER membrane and then are modified in the ER and golgi apparatus and finally delivered to the place where they need to do work. After all, where those the endomembrane system get its unprocessed protein cargo, of course, from the site of translation, ribosomes.