It will not attach to any organelle inside the cell during the entire process of translation. However, if the growing polypeptide chain that is being synthesized by the free ribosome is destined to be either secreted by the cell or to be embedded into the plasma membrane of the cell, in such a case, the free ribosome as well as the growing polypeptide chain will go on to attach onto the membrane of the endoplasmic reticulum. And now the free ribosome becomes a membrane bound ribosome. So a free ribosome is a ribosome that synthesizes polypeptides that are destined to remain inside a cytoplasm. But the membrane bound ribosomes are those ribosomes that are responsible for forming proteins that are either secreted by the cell or which remain inside the membrane of that cell. Now, the question that we want to discuss in this lecture is the following.