In this video, we're going to begin our introduction to the endomembrane system and to one of the major functions of the endomembrane system, which is protein secretion. The endomembrane system can be defined as a group of membrane-bound organelles that are inside of a eukaryotic cell. The root "endo-" and "endomembrane" refer to within the cell. The system here is referring to the fact that it's made up of a group of organelles, and all of these organelles are membrane-bound, meaning that their boundaries are comprised of membranes. The endomembrane system includes many different organelles, which we're going to mention below in this table. All of these organelles that are part of the endomembrane system are interconnected to each other by structures called vesicles. Vesicles are just a fancy name for these tiny little membrane bubbles that can carry materials on the inside. These organelles are interconnected by these vesicles, and we'll get to see examples of vesicles as we move forward in our course.
The endomembrane system has multiple functions, but we're not going to talk about all of the different functions. We're mainly going to focus on two of its functions: protein secretion, as well as cellular digestion. Below in our example, we have a table that shows the organelles of the endomembrane system. Notice the green color coding linking the organelles that we're going to talk about in our course moving forward that are involved with protein secretion. In yellow, we have the organelles involved with cellular digestion. With this white background, we have the cell membrane, which we're not going to focus on in this particular portion of our lesson. We will discuss cell membranes later in a different lesson. All of these numbers here show you organelles that are part of the endomembrane system, and we have them grouped based on their functions, whether they're involved with protein secretion or cellular digestion.
Moving forward in our course, we're going to focus mainly on the organelles that are involved with protein secretion, which include the nuclear envelope or the nucleus of the eukaryotic cell, the endoplasmic reticulum of the eukaryotic cell, the Golgi apparatus, as well as transport vesicles, which we mentioned again are these little membrane bubbles. Later in our course, we'll talk more about the organelles of the endomembrane system that are involved in cellular digestion, which include the lysosomes and peroxisomes, as well as vacuoles such as central vacuoles and others. This here outlines the organelles of the endomembrane system and groups them by their functions, and we'll get to talk more about each of these organelles as we move forward in our course. So, that being said, I'll see you all in our next video.