And we'll discuss that when we look at the mitochondria in its structure. In this lecture, we're going to focus on the structure and the composition of the nucleus, of the eukaryotic cell. So let's begin by discussing the envelope, the region that basically encloses our nucleus. This is known as the nuclear membrane or the nuclear envelope. So, just like the entire eukaryotic cell contains our cell membrane, the nucleus contains a membrane known as the nuclear membrane. And the nuclear membrane, just like the actual cell membrane, also consists of a lipid bilayer.