Where do ribosomes make proteins while they read the RNA?
Ribosomes translate messenger RNA (mRNA) into protein in the cytosol, outside the nucleus. Many proteins which are destined for exocytosis (released from the cell into the environment) or integration into the cell membrane (for signalling) are made by ribosomes which become associated with the endoplasmic reticulum, or ER, (also in the cytosol). In this case, proteins are translated by ribosomes and simultaneously inserted into the ER, and later transported in vesicles to the cell membrane.
