A vast system of interconnected, membranous, infolded and convoluted sacks that are located in the cell's cytoplasm (the ER is continuous with the outer nuclear membrane). Rough ER is covered with ribosomes that give it a rough appearance, the Smooth ER is not covered with ribosomes.
El Retículo Endoplasmático es un conjunto de sacos membranosos interconectados y plegadas, en el citoplasma. El RE rugosos está cubierto de ribosomas. El RE liso, no.