Now, the process by which our growing polypeptide chain is transported from the cytoplasm and onto the membrane of the endoplasmic reticulum along with the ribosome is known as translocation. And this is what we're going to discuss in this lecture. So let's begin by looking at the following diagram. So, we have the mRNA molecule that is being read by the ribosome as shown. And as it's being read, our ribosome is producing our polypeptide chain as shown. So the signal sequence is a special sequence of amino acids that are found at the beginning, at the end terminus of the polypeptide chain.