Inside of the cell there are a few organelles that have to interact with each other and work together and all of them are built from membranes. They have membranes that sort of enclose them So what we're gonna do is refer to all of these together as the endomembrane system. It's inside of the cell and at all all these organelles involve membranes. What these all do is they work together in order to manufacture and distribute things that the cell needs to be able to use. So we've already met a little bit of the endomembrane system. The nuclear envelope. This is one of the membranes that is involved in this system. So what we're gonna do is just move on down the list here. The endoplasmic reticulum, if you come over to the picture of the cell, see this sort of bluish purple section that's kind of wrapped around the nucleus. This is the endoplasmic reticulum. It has a couple of different sections. So we're gonna look at this next and then we will also be looking at the Golgi apparatus, which is in reddish orange right here lysosomes. These are tiny little things. These little circles. There's a lysosome. Here's another little one over here. Lysosomes are small little packages that can move around throughout the cell. And finally the plasma membrane. We've already talked about that one. It's a membrane and it's part of this endomembrane system. So let's go ahead and jump in with the endoplasmic reticulum and talk about what this does. The endoplasmic reticulum. It's a pretty large organelle. It extends to a number of different regions inside of the cell. This is in the cell right here. What we're doing is just showing a close-up of the endoplasmic reticulum. So let's jump over to this picture. Here it is. We've just kind of removed the nucleus right there. The endoplasmic reticulum has two different sections. It has this section that's called a rough endoplasmic reticulum or rough ER for short. A rough ER. It's called rough because it has a bumpy surface. And what these bumps are are ribosomes actually. So ribosomes are studded on the surface of the rough ER. There's this other section over here which is called the smooth ER. It's called smooth because it doesn't have those bumps on it. So smooth ER. These have two different jobs. The rough ER, you can probably guess what its job is. If it has a bunch of ribosomes embedded on the surface, this probably has a role in making proteins. And that's exactly right. Okay, so this is a site where proteins are made and they are packaged. They're packaged into little vesicles. And let me just move on to the next slide to show you this picture. So what we're looking at here is a close-up of one of the ends of the rough ER. Here's looking at that close-up. Here's a ribosome stuck on the surface of the rough ER. And this ribosome makes proteins. And the proteins that get produced, they come out, they happen to be on the inside of the rough ER. So they're in a perfect spot to be able to be packaged up. What's going to happen is this membrane will just kind of form a pouch at the end. And those proteins can be put inside the pouch. This can pinch off and this whole little thing. And that's kind of like a shell. This whole thing moves off. Now it's called a vesicle. Okay, so this is a transport vesicle. It's carrying the protein to wherever it needs to go. Maybe the cell needs this protein in the plasma membrane. If so, that's where this vesicle is going to head off to. So that's a close-up of what's going on in the rough ER. I'm going to back up to this slide one more time. We need to mention the smooth ER. This is doing a different job. Instead of making proteins, what it's doing is making lipids. And this is particularly helpful. This organelle is particularly helpful in cells that have to detox our blood. So like cells of the liver, the smooth ER really helps them to be able to do that effectively. Okay, so let's go ahead and move forward. That was the rough ER and this movie ER. Next up, we have the Golgi apparatus. So remember that vesicle that just pinched off from the rough ER? Right here, this vesicle. Where is it going to head? Well, eventually it might have an end goal, but it's probably going to make a couple of stops along the way. And the first stop that it's going to make is at the Golgi apparatus. So here's that vesicle coming from the rough ER. What it's going to do is meet up with the Golgi apparatus and it will fuse with the Golgi. So when it fuses, we say that the Golgi has received its contents. Okay, so the Golgi receives that vesicle and what the Golgi will do is make some modifications to the protein. It might sort the protein into a different sort of package and it'll ship it off to wherever the final destination is for that protein. A lot of times we say that the Golgi apparatus is like the UPS center of the cell. It receives things, it sorts them, stores them temporarily and it ships them out to wherever they're supposed to go. So that's the Golgi. The Golgi will ship things off in a vesicle again, same idea. It's made of membranes and those membranes can pinch off in sections in order to ship things out. Lysosomes. Lysosomes at a glance, they look like vesicles but there's something special about them. Lysosomes are little packages that contain digestive enzymes specifically. So lysosomes in cells do a very important job. They have the job of recycling things that are no longer working correctly. So maybe if there's an organelle that's been working for a long time and it's just starting to get worn out, what a lysosome would do is come over and digest it. It would recycle its components and helps to clean up the internal environment of the cell. So lysosomes, they are capable of breaking down all four types of biological molecules. So really handy things for the cells to have. Generally these are in animal cells but not plant cells. So that's one difference between those two cell types.