Those proteins are synthesized in the ribosomes, which are attached to one form of this organelle.
One variant of this organelle ("OR-guh-NELL") is found in muscle cells and stores calcium. Like the Golgi body, it is composed of flattened sacks called cisternae ("SIS-ter-nay"). This set of tubes contains chaperone proteins, which help fold proteins. Those proteins are synthesized in the ribosomes, which are attached to one form of this organelle. For 10 points, name this "packaging center" of the cell, which is divided into rough and smooth types.
One variant of this organelle ("OR-guh-NELL") is found in muscle cells and stores calcium.
{endoplasmic reticulum} [or {ER} ; accept {sarcoplasmic reticulum} or {SR}]