Inside the Cell Membrane | Structure and Function

I'm Dr. A. Are your cell membranes really the forgotten part of your cell? Hey, on this program, we talk a lot about the nucleus and the nuclear activity of cells and mitochondria and making energy and all of that. And sometimes I get questions of people saying, well, what about all the membranes that hold everything together? Aren't cell membranes important? Well, indeed they are. Welcome to my YouTube channel. I'm Dr. A, and I talk about holistic and integrative approaches to health. integrative approaches to disease states, functional disease states, all manner of other things. But I want to dive into this question about the cell membranes, and we're going to actually have a little playlist we'll develop because there's just so many juicy good questions about this. But the first thing is, is that we think about cell membranes, for those of you that are thinking about cell membranes, as, okay, we kind of have this sense that there's stuff going on inside the cell. If you watch a lot of my content, you see there's stuff about the mitochondria to make energy, et cetera. The nucleus to do all that it does. But then we think, well, the cell's defined by something, right? And when Dr. Van Leeuwenhoek first was looking under his little microscope, he was looking and he called them cells because they looked like rooms, right? Now, in animals, for the most part, we have cells that are very fluid and they do not have a cell wall on the outside. They still look like a little room, right? If you look at a plant, you will see a cell wall and then a membrane on the inside. So for us animals and humans, we have these very fluid, very dynamic cell membranes with no walls on them. And so they do a ton. So I'm not going to try and do it all in one video because, well, it'd just be a way long video. But I just want to get into this and talk about it a little bit. So the first thing is, it's not really like the walls of a house or something, but we describe it that way sometimes. The next thing is that these are super dynamic structures. It's not just one thing that makes it. The complexity of the way that these things are made is really quite quite intensely unique in my belief. And they're based on something called a phospholipid bilayer. And so if you think of this and you thought of something to look like a basketball on one end, okay, that is the phosphate head, phospho, and then 2 tails came off of the phosphate, that's the lipids. But then there's another set in a mirror image where the phosphate's on the top and the lipids go down and then the lipids touch in the middle. So the phospholipid bilayer is sort of the architecture of this. If we're Relating it to the walls of a house, it might be like the 2x4, 2x6 studs that are put into the wall of the house, right? Now, the phospholipid bilayer does have another, say, thing going for it, if you will, that makes the cell more functional. And that is on the outside and the inside where these phosphate heads are, the little basketball-looking things. That's a water-soluble environment, the extracellular space and the intracellular space. And so those are water-soluble areas, the phosphate In the middle, it's fat soluble because it's all fats in there. Well, for all intents and purposes, it's all fats in there. And so we call these things hydrophilic or water loving and hydrophobic or water repelling. Now, why would we want that in a cell? Well, for one thing, there's a lot of stuff outside the cell that we want to regulate going in and out. And also there's a lot of stuff we make in the cell that we may not want to leave, or we might want it to leave only at a certain time. And if that happens to be something that requires There's regulation, then we use some of the other parts of the cell membrane to try and operate this going on. But there's 2 things primarily that go back and forth inside the cell without real regulation. They just go down their gradient. Okay? Meaning if there's a lot on the outside of the cell and a little bit on the inside of the cell, it's going to go towards where the little bit is, right? Fats do this. Okay? So if I have a fat-soluble drug or I have some other fat-soluble thing my body has made, it will Go in and probably go either into the membrane or all the way through. Gases— oxygen, carbon dioxide, nitric oxide— gases in the body, they go in and out just based on their concentrations. So, if I am out at the end of, you know, my fingers here, and I've taken a deep breath in, and that oxygen's running around, it's going out to the cells at the end of my fingers, there's going to be more oxygen outside the cell than inside the cell for a brief moment, and it's going to go down its gradient into the cell. And then, Push the carbon dioxide out. It's going to go out. Well, that's how that works. The third thing that doesn't really follow the rules because of little pores is water. So water can kind of go in and out. The next thing though between this lipid bilayer is if that's the you know structure, that's the framing of of the house wall. There are also proteins, and so there are a couple types. So there's peripheral proteins and integral proteins. And so peripheral proteins are just what they mean. They're either stuck on the outside or the inside of the cell membrane. These often are there for communication. Communication with stuff around. They might be a receptor. They may do all other stuff. And there's integral protein. Integral proteins mean they go all the way through. Remember, there's a whole class of things that can't get through the cell membrane. Water-soluble stuff, right? Remember I said water got its own little pores, but water-soluble stuff. What if I need to get calcium or magnesium or potassium inside or outside my cell membrane? What if I need to get a water-soluble nutrient beyond minerals inside or outside? What if I need a drug to go into my cell that's water-soluble, et cetera, et cetera? Well, there has to be these things that help it go in. So an integral protein, you can think of like sort of a channel. So that'd be like the door, right? But the door isn't open all the time. Normally at our houses, what do we do with the doors? When we leave the house or at night we go to bed, we close the door and maybe lock it, right? Well, it's kind of the same with your cell. These doors are there, but they're not just sort of saying, hey, everybody come on through who's water soluble. They have different ways of allowing the right thing to go in. And not allowing the wrong thing to go in. So this happens a lot where they have a little key, lock and key system where they might only allow 1 or 2 or 3 types of minerals in. There are some transporters that are just for 1 mineral. There's some that are for 2, some that are even for 3. Very exciting. And then there's some transporters that while they're putting 1 mineral in, they force another one out. Okay. Countertransport. So those are the integral ones. Peripheral ones do things often we call them like second messenger things and stuff like that. Stuff that doesn't have to go inside your cell. So a hormone comes along, it triggers a second messenger activity, but it just binds on the outside to this peripheral protein. That protein doesn't go into the cell. It sends hormone binds, it sends chemical information inside the cell. Then second messenger systems are turned on. So I don't have to put that chemical or hormone or whatever in inside the cell there. The other questions that came up were really around how is it that the cell Regulates itself, helping, you know, with the cell membrane, but also talks to the other cells because we have cell-to-cell communication. Now, this has gotten real popular during COVID because of immune cell communication. We hear, we read about that all the time, and that's through different chemistry. It's just, it's the same basics, right? Because immune cells are made like all these other cells we're talking about. But cell-to-cell communication can be that a cell has a peripheral protein. And that peripheral protein might interact with the neighboring cell's peripheral protein. And if they are chill and they don't have much going on, then all is well in the neighborhood. Or if this peripheral protein on this cell starts to change the way it's made, then the other one changes the way it's made and it tells the other cell, we're doing something different here, or there's an attack or there's some other thing going on. So that's a lot how we do it. But there's also other ways that the cell can communicate. And that can be from the inside of the cell. We may have something that we want to make in the cell. This happens in our brain cells. It happens in our hormonal cells. It happens in all kinds of cells. And we make a product, but we just don't want, like, to have this product, you know, go willy-nilly out there into the cellular milieu and do weird stuff. And so what we'll do is we'll make the product and we'll have it made up in these little packets. Okay. Those are called vesicles. And we'll have all those packets waiting. And then when we get a triggering stimulation, We release those packets. Why would we have this elaborate thing with the cell membrane and gatekeeper for these, these little packets? Well, you think of it now, as I said, many types of cells do this, but think of it like your brain. Okay. You have neurons in your brain. They make all kinds of different things. We've all heard of like serotonin or dopamine or other stuff like that. If I just have a serotonin, serotonergic cell, okay, and it's just pumping out serotonin all of the time, right? That's not a regulated system. And your brain literally is either gonna shut off or you're gonna hallucinate. Literally, that's one of the things that can happen, or some other very bad thing will happen. You can die from things like this. What I want is the serotonin-producing cell to make lots of serotonin, put in these little packets and wait. And then when I get a signal coming down that says, hey, serotonin-producing cell, may we please have some serotonin go downstream, then it will release. an appropriate number of little serotonin packets that go out and they do their little serotonin job. Now, this goes on elsewhere in the body too, but you can see it's a regulatory mechanism. This is all done elegantly through the cell membrane, the internal peripheral type protein, and then a bunch of other mechanisms that we're really not getting into at this moment. Now, could a cell use that same process, this vesicular a process to get rid of garbage? And the answer is yes. So, your cell might make good things, you know, that you want to regulate, like serotonin or dopamine or something. But your cell also can just put packaged stuff up that it would really like just to get out of the cell because it's done, it's toxic, and it wants it to go out and be eliminated by the body. So, that also happens quite a bit. So, just remember that it could go either way there. Now, we're going to do a different Uh, talk on a different video about how might this complexity lead to disease. But I just want to wrap up and wrap our minds around this idea that the cell membrane around is kind of like the walls of a house, but it's very complex. So it's got the equivalent of the studs in the house and the doors and the windows and, and maybe even some, you know, receptors on the inside and outside. So there's a lot of stuff going on. But it's also how it communicates with other cells to help keep us healthy. It's how it imports good stuff and gets rid of bad stuff. And it is done in a chemical way that is so elegant that under normal conditions, without beating it up too badly, we have cells that operate healthfully for a long time. When we beat up the cells too long, or when we make the environment that that cell lives in too sick or too toxic, then Diseases and dysfunctions and other bad things will ensue coming from there. That's a topic for another one of our little talks that's going to come up where, as I said, we're gonna build a cell and cell membrane video list. If you like this video, you're probably gonna like some of the other videos that we talk about. I answer a lot of questions through video as opposed to typing them out into the Q&A boxes, cuz it's just easier. So check us out on main YouTube channel. That'll be the first link down below in the description box. A bunch of links to other things down there. as well. I'm Dr. Ray, and I will see you on the next video coming up.