| 00:10 | alright. In theory, everything is Hopefully. Let's see. Sounds like |
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| 00:20 | feels like it. All right. , if you're new class, this |
|
| 00:24 | the big the big gist from uh , it's actually a lot more |
|
| 00:28 | So basically gone blackboard. Uh I all the lectures. That's not an |
|
| 00:32 | again to skip class. It's there's convenience. If you decided to educate |
|
| 00:38 | by just watching videos, you're I'm just gonna tell you that up |
|
| 00:41 | because you're not self learners or self , even though it feels like it |
|
| 00:45 | you'll perform a lot better if you attend all your classes, and I'm |
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| 00:49 | you this from a person who skipped of their classes in college. |
|
| 00:53 | I'm just letting you know anyway, sure you buy the book. Everyone |
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| 00:57 | a look yet. Yeah. You're working on it. All right. |
|
| 01:01 | remember we got pre reading quizzes, if you're guessing your way through those |
|
| 01:04 | luck. Um Lastly, uh do orientation quiz which is due um at |
|
| 01:10 | It's not up there. There it friday on september 2nd. So, |
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| 01:15 | got some time if you have questions the class, if you if it's |
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| 01:18 | answered in the recorded lecture, you go ahead and email me. That's |
|
| 01:22 | the very first slide. We're going have one of those days. All |
|
| 01:29 | . I hope I'm not walking back forth 1000 times. There we |
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| 01:33 | Alright. So what we're gonna do we're now jumping in feet first, |
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| 01:38 | so what I want to first do define what this class is in terms |
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| 01:41 | what you're actually learning. What is , is the study of normal functioning |
|
| 01:46 | things you're interested or the reason you're this classroom, I'm guessing is because |
|
| 01:51 | interested in pathology. Right. I , your your entire life, if |
|
| 01:57 | planning on going into health professions, are here not because you want to |
|
| 02:00 | how the body works, you want know why isn't it working? That's |
|
| 02:03 | you want to go and do. deals with the things that are wrong |
|
| 02:07 | the body and we're not covering So, I'm sorry if you're gonna |
|
| 02:11 | a little bit disappointed, this is a medical school class where we teach |
|
| 02:14 | how to fix things. What I to do in this class is teach |
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| 02:17 | how things work. So that when go and take the class again in |
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| 02:21 | or dental school because you will write you will learn that this is what |
|
| 02:27 | is supposed to be doing. So . Talking about how the organism or |
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| 02:30 | system or the organs or the cells nowadays, even further, the biomolecules |
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| 02:36 | supposed to behave so that your body function and do the things it was |
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| 02:41 | to do. All right. that's really what all this is and |
|
| 02:45 | course is a subdivision or a sub of biology. Alright. And what |
|
| 02:50 | that mean? Well, if you're biology major, you kinda already have |
|
| 02:53 | sense of this, right? Let's of all the classes you get to |
|
| 02:56 | , You get to take genetics. just gonna go up the line then |
|
| 02:59 | get to take evolution. And then evolution you get to take cell |
|
| 03:07 | those are all required ones. And so think about, I mean |
|
| 03:11 | , we're doing it because it helps understand how all these systems are |
|
| 03:15 | But for example, genetics and cell . Give you an underpinning or an |
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| 03:20 | of how all these systems come about and work. If you stick around |
|
| 03:24 | me and next semester you decide to comparative anatomy and I'm not suggesting that |
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| 03:28 | no one needs to or that you write. But if you do |
|
| 03:31 | what we do is we do this across species of why fish and animals |
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| 03:37 | dinosaurs and humans and animals but mammals all alike, even though we don't |
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| 03:43 | the least bit like each other, ? And we've done that, haven't |
|
| 03:46 | ? Yeah. Alright, so the thing about physiology and you'll hear this |
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| 03:51 | and over again, the central theme homeostasis. How does the body maintain |
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| 03:57 | constancy despite the changes that are going all around us. And so part |
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| 04:01 | our focus is is to look at mechanisms to allow that to happen now |
|
| 04:07 | said all that and if you feel , oh my goodness, this is |
|
| 04:10 | be this crazy hard class now up is the list of all the systems |
|
| 04:14 | our body, with the exception of that's not listed up here, which |
|
| 04:17 | the immune system because we kind of it and leave it on its |
|
| 04:20 | But we have all these different systems as a group mumble it if you |
|
| 04:26 | to because you're an introvert. Let's what all these systems use. Tell |
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| 04:29 | what does the integra mint system That's your skin. What do you |
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| 04:32 | it does protect you? Good. does the muscular system do? |
|
| 04:36 | Good, skeletal system structure. I that. So I was gonna say |
|
| 04:41 | , but it is structure and protection well. These are this is like |
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| 04:45 | big picture stuff, right? Um about the nervous system? Exactly? |
|
| 04:53 | communication, right? It's talking Talking to systems endocrine more of the |
|
| 04:59 | . So systems talking to systems I'll up front with this endocrine system is |
|
| 05:03 | a real system, it's just a of organs that are like each other |
|
| 05:06 | the sense that they communicate. And we can't put them in any other |
|
| 05:09 | , we throw them all in a together. Okay, uh circulatory |
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| 05:13 | blood, it's to move information around body. And again it's it's in |
|
| 05:19 | with other systems, right? Move , waste, move materials like uh |
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| 05:26 | move materials like oxygen. Get rid materials like carbon dioxide. Right? |
|
| 05:30 | so again, it works with other , lymphatic is a little bit more |
|
| 05:34 | . One of the things you think is probably yeah, lymph lymph |
|
| 05:39 | And so what you immune system. it's kind of defense. That's part |
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| 05:44 | its job. It's a place where defense mechanisms are arranged. But that's |
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| 05:49 | its only job. It actually works conjunction with the circulatory system. But |
|
| 05:53 | answers are not wrong. It's part the answer. Alright, respiratory |
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| 05:57 | And another one get my oxygen and rid of my carbon dioxide digestive |
|
| 06:03 | No one said cheeseburgers. Right. it's materials and and nutrients to for |
|
| 06:09 | body. Right? And processing that system secrete waste. Um And the |
|
| 06:16 | system reproduction. No one said bow . Bow wow. All right. |
|
| 06:21 | so you can see that both males females have their own unique reproductive |
|
| 06:25 | Alright. But what you just gave here was like the big picture of |
|
| 06:28 | big overview that we should all know kind of walking in here. And |
|
| 06:31 | any of those were kind of surprising you, that's okay. We're going |
|
| 06:35 | cover all of those over the course the semester. But while we look |
|
| 06:39 | these things in very very simple kind boxes, we need to understand that |
|
| 06:43 | have these shared functionalities as well. . So while we might think of |
|
| 06:48 | for the skin, it also plays heavy role in metabolism. Right? |
|
| 06:52 | responsible for immune defense. There's all different aspects that are gonna be shared |
|
| 06:57 | the different systems. So one of best ways to approach physiology is to |
|
| 07:02 | broader questions and then use those answers answer more specific questions. And so |
|
| 07:08 | the way this first unit is actually or created is kind of to get |
|
| 07:12 | first all on the same page, know, in in the sense of |
|
| 07:16 | biological knowledge, but also to present ideas or these concepts that are going |
|
| 07:21 | repeat themselves over and over and over . So once you learn the |
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| 07:26 | it doesn't matter if you go into cardiovascular system or go in the renal |
|
| 07:29 | or if you go in the into respiratory system, those same truths are |
|
| 07:33 | to be carried over and over and again. And one of the reasons |
|
| 07:36 | you see, you know biologists and , looking at evolution and going, |
|
| 07:40 | . It's because these kind of concepts reappearing over and over again. So |
|
| 07:44 | conserved across systems and across organisms as . Right? So that's kind of |
|
| 07:51 | reason why we harp on this over over again. So even if you're |
|
| 07:54 | being planning on being a biologist and you keep hearing this go evolution, |
|
| 07:57 | , evolution. Evolution. Just understand we're trying to do is say, |
|
| 08:01 | the basic concept and if you get concept, you can apply it |
|
| 08:05 | alright, I'm always pointing at the thing. The thing I need to |
|
| 08:08 | out is over there. Alright, first off, one of the things |
|
| 08:11 | gonna learn about me is I like use a lot of imagery when I |
|
| 08:15 | . All right. And part of imagery is to help you understand a |
|
| 08:18 | bit about yourself. So, one the things that we are is like |
|
| 08:22 | jar right here. Alright. And lives our bodies are very similar to |
|
| 08:29 | in the sense that we are governed this concept called the law of mass |
|
| 08:33 | or the law of mass action. you spend enough time in chemistry, |
|
| 08:37 | probably familiar with the law of mass , but it's the same sort of |
|
| 08:41 | . So, I'm gonna kind of you a picture of this. You |
|
| 08:43 | like Oreos. Yeah, double Okay. All right. I want |
|
| 08:50 | to imagine in front of you is plate of Oreos. And if you |
|
| 08:53 | like Oreos, well, we're gonna a conversation. Alright, there's four |
|
| 08:57 | on the plate. The rule is that you can have as many Oreos |
|
| 09:02 | you want, but you have to them. Right? The pantry has |
|
| 09:07 | Oreos. There's a good example, it? Right? You can do |
|
| 09:11 | also with with Eminem's but I'm doing today. All right. So, |
|
| 09:16 | want to eat an oreo. I an oreo show down my mouth I'm |
|
| 09:18 | . But the plate is now one deficient. So I have to go |
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| 09:21 | the pantry and get an oreo, want to Oreos. I stick into |
|
| 09:24 | mouth and good. I have to to the pantry and replace those two |
|
| 09:28 | . And other words that plate always to take when something is taken |
|
| 09:33 | All right. And that's kind of our body behaves. When we put |
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| 09:37 | in our body, we are overloading plate. Right? So, if |
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| 09:40 | take two extra rows and put six on the plate, I am now |
|
| 09:44 | . What do I have to I have to eat those Oreos. |
|
| 09:48 | rid of them. No, no. I eat those organs. |
|
| 09:51 | you tell? I mean, come , look at that. Right. |
|
| 09:54 | , that's the idea is that with law of mass balance, it says |
|
| 09:58 | when we're looking at something for it be in homeostasis, that means if |
|
| 10:02 | comes in something has to go out something goes out, something has to |
|
| 10:06 | in. Now in a really simple . What we can do is we |
|
| 10:09 | look at something like water. If goes, if I drink water, |
|
| 10:12 | do I have to do? I to pee it out if I sweat |
|
| 10:15 | out of my body, what do have to do, drink water? |
|
| 10:18 | right. So, that's real But remember you have to take chemistry |
|
| 10:21 | organic chemistry to take this class. . Right. And we forget that |
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| 10:25 | are chemical reactions that use up water we don't think about it. |
|
| 10:30 | Right. Whenever we break a bond also breaking water, right? Hydraulic |
|
| 10:35 | And that water is now used to make those uh that broken bond um |
|
| 10:42 | . We're fixing it, right? hydra lies in one and we're hydroxy |
|
| 10:47 | the other side. Right? when I do that, when I |
|
| 10:50 | that water, I have lost So I have to replace that |
|
| 10:54 | So, my chemical reactions have to a role in this as well. |
|
| 11:00 | ? So every anabolic reaction and every bolic reaction has to be considered for |
|
| 11:05 | that goes in and goes out and of a sudden now you can start |
|
| 11:07 | this is a really complex system that being governed or that governs over our |
|
| 11:13 | . All right. So, when think about these things, it's like |
|
| 11:16 | easy stuff is up here, intake excretion. Yeah. Okay. But |
|
| 11:19 | also have to remember all the metabolism taking place as well to ensure that |
|
| 11:24 | Oreos stay on our on our What happens if I throw up the |
|
| 11:30 | ? What do you think? What do I have to do? |
|
| 11:35 | got to put them back in the . Right. I've got to I've |
|
| 11:39 | to get them off the plate. the idea. So systems that work |
|
| 11:43 | way. Always work the other They're all reversible. And I'm gonna |
|
| 11:47 | in quotes in theory. All Or maybe I should put reversible And |
|
| 11:50 | say in theory is probably the correct . Alright. So, that is |
|
| 11:55 | primary function of the body is to homeostasis through that process. Now. |
|
| 12:02 | other thing about our body that's kind interesting is that we are like |
|
| 12:06 | All right. And I'm not talking really crappy apartment where it's like one |
|
| 12:10 | and two toilets in the middle of room type stuff. I want you |
|
| 12:12 | think about your apartment or your dorm or your home room. All |
|
| 12:15 | And I want to think about this . I want you to tell me |
|
| 12:18 | that room is for. All Do you have a bedroom? |
|
| 12:23 | That bedroom for? Do you have kitchen? What's it for cooking? |
|
| 12:28 | you have a bathroom? What's that screening? Watching? You know, |
|
| 12:33 | the evolutions and all the other fun that we kind of don't talk about |
|
| 12:36 | mixed company, but this physiology. , get used to it. |
|
| 12:39 | Uh Do you have a living room a living space? What do you |
|
| 12:43 | there email that? What I heard . Okay. Hang out. |
|
| 12:49 | So entertained. Right. So, can be Yeah. I don't |
|
| 12:52 | I said, you know entertain. ? You can entertain friends or entertain |
|
| 12:56 | in a in a public space. now, answer the answer the question |
|
| 13:02 | . Can you entertain in your Can you is it allowed? Is |
|
| 13:08 | is it proper would mother be No? Okay so that's the answer |
|
| 13:12 | you gotta go with. Right, you eat in the bathroom? No |
|
| 13:17 | mean you can but should you I maybe that's a better question. Should |
|
| 13:21 | eat in the bathroom? No. . You see. So what you |
|
| 13:24 | here is you have a space that been designed with compartmentalization in mind. |
|
| 13:29 | ? In other words their specialization. you sleep in the bedroom, you |
|
| 13:33 | in the kitchen, you entertain in living room, you use the bathroom |
|
| 13:37 | whatever way necessary for the bathroom. put your clothes in the closet, |
|
| 13:41 | on the floor. Okay. Your and your body is designed the exact |
|
| 13:46 | way. In other words there are many chemical reactions that we have to |
|
| 13:50 | these incredibly unique environments for those chemical to take place. And so your |
|
| 13:57 | is divided up into these two So if you consider your skin as |
|
| 14:01 | boundary between the internal environment, in external environment, your internal environment is |
|
| 14:06 | . And so that the two spaces there is in terms of fluid exist |
|
| 14:11 | cells or outside cells. Outside cells call that extra cellular fluid. See |
|
| 14:16 | even says in the name inside the we call that intracellular fluid. |
|
| 14:22 | And so what we've done now we've the bodies. What we've said is |
|
| 14:26 | the cell that structure is a unique for something to happen Now, just |
|
| 14:33 | be up front, which we're not have to deal with. There are |
|
| 14:36 | 300-400 different cell types that we're aware in the body. We're not gonna |
|
| 14:42 | at all of them, thank Right once you start diving deep in |
|
| 14:47 | biology, start looking going, oh goodness, I can't believe this is |
|
| 14:50 | subdivision of that subdivision of that Right, But the idea here |
|
| 14:55 | for example, if I want to something, right, I'm gonna have |
|
| 14:59 | cell that is specialized for that to . And so the chemise reactions for |
|
| 15:05 | to allow to process light energy has have a unique environment separated from everything |
|
| 15:11 | . And so that's why we've compartmentalized material. Alright, So intracellular fluid |
|
| 15:18 | the environment that is best suited for chemical reactions that are taking place inside |
|
| 15:22 | specialized cell. The extra cellular fluid the environment surrounding the cells. So |
|
| 15:28 | allows the cell to communicate or sits cells and and there as a point |
|
| 15:34 | communication. Right? So, in extra cellular fluid, we're going to |
|
| 15:40 | a unique environment so that molecules can or move between cells or between different |
|
| 15:47 | of the body and so forth. , your book kind of gave you |
|
| 15:51 | picture, which is a little confusing it says, look, here's the |
|
| 15:54 | , there's your extra cellular and then says, okay, we're gonna divide |
|
| 15:56 | in half which we do. The cellular fluid is divided into two |
|
| 16:00 | We have the stuff that literally sits the cells and the name literally says |
|
| 16:04 | between the cells, fluid in between cells fluid. Right? But then |
|
| 16:09 | have this weird stuff. The plasma is in contact with the interstitial fluid |
|
| 16:14 | really is the fluid that's circulating in cardiovascular system. All right. And |
|
| 16:18 | this is a a division that basically as transport that mixes back and forth |
|
| 16:24 | the interstitial fluid in very specific All right. So, the exercise |
|
| 16:30 | fluid we get to divide again E. C. F. And |
|
| 16:33 | . And and the interstitial fluid. I C. F. Inside the |
|
| 16:38 | . It's unique and characteristic wise, from and separated from the E. |
|
| 16:42 | . F. The E. F. Is divided. The two |
|
| 16:46 | in the E. C. Are the same with some very small |
|
| 16:49 | which we'll get to a little bit and there is mixing that takes place |
|
| 16:53 | them. Alright, so far you're me. If you look at the |
|
| 16:58 | , you're gonna see this thing. cellular fluid. We're gonna ignore |
|
| 17:01 | Alright, So, just say it's . But I'm gonna ignore it. |
|
| 17:05 | not gonna ask you a question about . If you want to talk to |
|
| 17:07 | about it later. Yeah. The is basically the fluid. It's the |
|
| 17:13 | cellular fluid in the compartment of the system. It's it's the water of |
|
| 17:18 | blood house that the fluid of the is the better way to say |
|
| 17:21 | All right now, there's always a of words on my slide. But |
|
| 17:26 | to help you later. Okay. , what I want to make sure |
|
| 17:31 | understand is that homeostasis is not the thing as equilibrium. Think about a |
|
| 17:35 | reaction. You put something in on side, you create a balance and |
|
| 17:39 | basically chemical reaction goes until there's balance both sides of the equation. |
|
| 17:42 | Remember that? That's that's basically kim And kim to organic chemistry is all |
|
| 17:47 | definitions of all the scary words that using. Now. Don't tell the |
|
| 17:52 | . I said that. Okay, homeostasis in and of itself is not |
|
| 17:59 | . Alright, equilibrium is when you things into equal liberation or the |
|
| 18:06 | Same. Alright. So, right , what is your body temperature |
|
| 18:11 | 90°. But this is science. We talk about 2°F? 37°C. Yeah, I |
|
| 18:18 | . I know it's hard. Life's 37° seat. All right. What |
|
| 18:23 | the room temperature do you want to ? 25. Right. Are you |
|
| 18:27 | equilibrium with the external environment? but you're a homo static balance, |
|
| 18:31 | you? Aren't you? Well, some of you are not some of |
|
| 18:34 | might be a little bit hot. what are you doing? You're sweating |
|
| 18:37 | bring your body down into temperature. of you are cold blooded in or |
|
| 18:41 | nature, like my wife. And you bundle yourself up in here and |
|
| 18:44 | you're shivering and you're and you're basically your body temperature up to bring it |
|
| 18:48 | to homo static balance. So, see this distinction here between equilibrium and |
|
| 18:54 | . Alright. Now, with regard the, with regard to the body |
|
| 18:59 | regarding to those fluids, we are in chemical equilibrium at all. We're |
|
| 19:04 | chemical disequilibrium and that's this little tiny here on the bottom. Does And |
|
| 19:08 | you go up there and you can see some real numb as well if |
|
| 19:10 | want to. We're not interested in numbers so much. I'll just tell |
|
| 19:13 | right now, we're not gonna do lot of math in the class. |
|
| 19:16 | physiologists, you know, relish torturing with horrible math. I don't do |
|
| 19:20 | because math sucks. I mean, I don't enjoy math anymore. But |
|
| 19:26 | this chart shows you, It look, alright, P stands for |
|
| 19:30 | do you think plasma? It's up . Some Oh, that's the other |
|
| 19:34 | . If I ask you a the answer is usually right up behind |
|
| 19:37 | . All right. So, we plasma. We got Yeah. And |
|
| 19:40 | we have that's gonna be the So inside cells. All right. |
|
| 19:44 | so what this is showing you that , look, what are the concentrations |
|
| 19:47 | sodium, Well, look, concentration sodium in the extra cellular fluid is |
|
| 19:52 | same. Doesn't matter if you're in plasma or inside or in the interstitial |
|
| 19:57 | . It's an equilibrium with itself. ? Because it mixes just one travels |
|
| 20:01 | the body. The other one just of hangs out. But look at |
|
| 20:04 | sodium inside of cells, it's really low. Okay, potassium you |
|
| 20:11 | see there's a difference chlorine, you see a distance bicarbonate. If you |
|
| 20:15 | know this one, this is when just kind of memorize that's bicarbonate, |
|
| 20:19 | equal large an ionic or large and . And proteins. Really what we |
|
| 20:24 | is we just take away the and just called large an ionic cellular |
|
| 20:28 | Where do you see all the large ionic cellular proteins? Well, if |
|
| 20:32 | cellular proteins inside the cell, If plasma proteins in the plasma, notice |
|
| 20:36 | nothing here. Okay, So, there's not a lot of equal going |
|
| 20:41 | . All right. So, there's chemical disequilibrium and that chemical disequilibrium is |
|
| 20:47 | because you need to have that imbalance those chemical reactions that are taking place |
|
| 20:53 | the cells. So, this is of those types of environments. It's |
|
| 20:58 | you we've made a unique environment So, something special can happen. |
|
| 21:04 | what that all represents. Now. you look at those the first four |
|
| 21:07 | those actually, even the fifth They're all ions, aren't they? |
|
| 21:11 | know you can't see over there. there you go. But you see |
|
| 21:13 | all ions? Yeah. Okay, you're an ion, do you have |
|
| 21:17 | charge? Yes. Right. So you have a one valence of a |
|
| 21:23 | valence, that means you're positively right? And you can see there's |
|
| 21:27 | negative charge and those things are attracted each other because opposites attract yada yada |
|
| 21:31 | . So you can imagine that there's attraction for these two things. There's |
|
| 21:36 | an attraction for those two things. attraction between that and interaction between that |
|
| 21:39 | so on and so forth. Your body is electrically neutral. What |
|
| 21:47 | that mean? Well, it means all the positive negative charges in your |
|
| 21:50 | , if you sum them all up the same. How do we know |
|
| 21:54 | ? Well, I can touch You don't get electrocuted. It was |
|
| 21:57 | it was not the same electrons would and there would be current, There's |
|
| 22:04 | current. But by looking at just by the ions, you can |
|
| 22:08 | that there is a disequilibrium, isn't ? So there's an imbalance in |
|
| 22:13 | And where do the charges want to ? They wanna go find their |
|
| 22:16 | Right. So what that means is now we have chemicals that are |
|
| 22:21 | of balance there in disequilibrium. So do they want to do chemistry teach |
|
| 22:26 | ? They want to find equilibrium, ? And if you have electrical charges |
|
| 22:30 | of balance, what are they gonna do? They want to neutralize each |
|
| 22:34 | . So what we have here is have mechanisms that the cell has created |
|
| 22:39 | moving these particular ions and many others we're not listing that they can now |
|
| 22:45 | to do work. Alright, so disequilibrium has a twofold purpose purpose. |
|
| 22:52 | one create unique environments so things can purpose. Number two, I can |
|
| 22:59 | to create work. How many guys done physics yet? Okay, |
|
| 23:03 | So you guys are familiar with work right for the rest of you who |
|
| 23:07 | do it? Don't worry, you'll to get there. Right. And |
|
| 23:10 | basically what you're doing now, you're , oh, now this is why |
|
| 23:13 | have to take that stupid physics class be about. Yeah, purpose number |
|
| 23:19 | create unique environments. Right? So reactions can take place purpose. Number |
|
| 23:24 | is to allow for that this that creates potential energy that we're going to |
|
| 23:31 | be able to use for work. . All right. So we're electrically |
|
| 23:37 | but were chemically imbalanced. Well, not the right word. We're in |
|
| 23:41 | disequilibrium and we're in electrical disequilibrium. right, now, the interesting thing |
|
| 23:46 | this disequilibrium is that chemical disequilibrium and disequilibrium are basically going the opposite |
|
| 23:54 | So, I want you to imagine slope basically what we're saying is if |
|
| 23:57 | have a lot of sodium over here very little sodium over there. The |
|
| 24:01 | the electrical charge for every time you and one of those sodium is |
|
| 24:06 | you're moving a positive charge. And what you have is you have a |
|
| 24:09 | going the other way saying, here's negative, here's my positive, you're |
|
| 24:12 | moving towards negative. And so what , there's gonna be a point where |
|
| 24:16 | two slopes cross and meet. It's even this side. Right? So |
|
| 24:20 | guess I'm talking about osmolarity at this . So let me just back up |
|
| 24:23 | this is why I get really excited I start talking about something. So |
|
| 24:26 | need to kind of see what we're be talking about here. This is |
|
| 24:28 | we have slides just so I can what we're gonna be doing. Oh |
|
| 24:31 | , yeah, yeah. So so two things are in a steady state |
|
| 24:34 | really what it is. And so what this is saying is like, |
|
| 24:37 | , even though you see this the body has found a point where |
|
| 24:42 | right now represents homeostasis. Alright. has moved where it needs to |
|
| 24:48 | The ions have moved to where they're go. And so we've done is |
|
| 24:50 | created this balance that can then be to create that work. Alright. |
|
| 24:56 | so that work is gonna be dependent how we allow these ions to move |
|
| 25:01 | the different compartments. Alright, so use this for a moment. And |
|
| 25:05 | regard to sodium. Alright, remember want to create equilibrium, that's what |
|
| 25:09 | all agreed on equilibrium. Good Disequilibrium things bad. We get really, |
|
| 25:14 | upset about those things. So we to balance our equations right inside the |
|
| 25:17 | . We don't have a lot of , very little sodium over here. |
|
| 25:20 | of sodium outside the cells. So have a barrier between those two |
|
| 25:24 | The sodium can't come in. But I can open up that that |
|
| 25:28 | sodium is gonna naturally want to go its concentration gradient, right? It's |
|
| 25:34 | following osmotic considerations. If you've ever that term, it's basically moving down |
|
| 25:39 | concentration gradient until we can get Similarly for potassium, there's lots of |
|
| 25:45 | inside the cell, a little bit potassium on the outside of the |
|
| 25:48 | potassium wants to flow out of the . Alright, And it's this what |
|
| 25:52 | was referring to, the dual part two is we're gonna use that tendency |
|
| 25:57 | those molecules to want to move in directions to do the work that the |
|
| 26:00 | want to do. And what we're is we're just gonna do osmotic. |
|
| 26:04 | refer to this as osmotic considerations? is gonna go where there's less |
|
| 26:08 | If there's less sodium, that usually there's more water. Did you guys |
|
| 26:13 | about osmosis. Can anyone here explain ? Oh, you are, you |
|
| 26:19 | the gold star for the day because in chemistry they say water or osmosis |
|
| 26:24 | moving from an area of higher solute , which just blows your brain because |
|
| 26:29 | like, wait a second. We're about water and you're over here talking |
|
| 26:31 | salutes. Right? It's It's water , that's all it is. |
|
| 26:36 | So, anyway, so, we're use that and we're gonna use the |
|
| 26:41 | permeability of the membrane to allow materials move, to allow us to do |
|
| 26:46 | work that the cell wants to All right. So, now, |
|
| 26:50 | think I'm gonna get to this this know, I'm talking about the plan |
|
| 26:54 | right now. I'm gonna get I promise. Because on that |
|
| 26:58 | I know there's an ernst equation which not gonna have to learn, but |
|
| 27:00 | there for a reason. Alright. , the plasma membrane is that |
|
| 27:05 | Alright. The plasma membrane is like wall. Like it is not a |
|
| 27:10 | . It's like a wall. All . If I want to get to |
|
| 27:12 | other side of the wall, can get through it? Not this |
|
| 27:17 | I can't get through that if I hard enough maybe, But not this |
|
| 27:20 | . All right. It is basically structure that allows for this compartmentalization from |
|
| 27:27 | cell to the external environment. So, what that means is is |
|
| 27:32 | it is responsible for physical isolation of materials on the inside of the |
|
| 27:36 | It creates the environment so that you do unique metabolic activity. It regulates |
|
| 27:41 | goes in and what comes out. like the door, right? The |
|
| 27:45 | allowed us to come in and allow other students to go out right |
|
| 27:50 | Is that door selective? If this door is not right, anybody can |
|
| 27:55 | in and anybody can go out students, faculty members, whatever. |
|
| 28:01 | ? But we could create a door only lets one thing in and goes |
|
| 28:05 | . So there is a selectivity to we can allow to go in and |
|
| 28:08 | out. So, what that means we have something that we're gonna have |
|
| 28:11 | to regulate and decide what is going create that regulation. Alright. But |
|
| 28:16 | we can move anything in and out the cell. Second thing it allows |
|
| 28:20 | to communicate between cells. If I'm unique compartment among my with myself and |
|
| 28:25 | a cell next to me that is is also unique compartment. And I |
|
| 28:29 | to tell that cell to do the thing that I'm doing and we're kind |
|
| 28:32 | the same. I can communicate with . All right. If I'm an |
|
| 28:36 | cell that's trying to tell another immune what to do, all I gotta |
|
| 28:39 | is come next to it. And I have the right receptors and the |
|
| 28:42 | Liggins for them to come into contact each other, those two cells can |
|
| 28:46 | to each other. Now, that's , communication. But there are other |
|
| 28:50 | of communication where I'm way over you're way back over there. |
|
| 28:53 | I have to send you a Right? And so there are things |
|
| 28:58 | the surface of the cell, different of receptor proteins that allow for communication |
|
| 29:03 | take place. So it doesn't matter we're next to each other far away |
|
| 29:08 | plaque remembering plays in a very important in communication. And lastly, in |
|
| 29:13 | of structural support. Um when you at a cell, you'll see that |
|
| 29:17 | has kind of a unique shape depending which environments it's located in. |
|
| 29:21 | cells are not just cute little round that you draw pictures of in high |
|
| 29:24 | . Right. Remember when you looked the microscope for the first time through |
|
| 29:28 | cell and put the nucleus, Oh , there's a mitochondria and it doesn't |
|
| 29:31 | anything like the book. But I'm gonna do this because the teacher said |
|
| 29:33 | what it looks like. Right. the cell has proteins that are embedded |
|
| 29:39 | that membrane and attached to even larger that help to create the shape. |
|
| 29:45 | allows the cell to do what it . We're gonna see some really interesting |
|
| 29:49 | in the class. I mean muscle are an easy one. They have |
|
| 29:52 | unique shape. That's really easy to , neurons have a unique shape. |
|
| 29:55 | easy to identify. We have two in the eyes. I mean, |
|
| 29:59 | see if you can guess the name first cells called the rod cell. |
|
| 30:02 | the other one is called the cone . What do you think their shapes |
|
| 30:05 | rotten. Right. And so you kind of see here is that these |
|
| 30:10 | allow those cells to do what they . And it's because of the unique |
|
| 30:16 | that that permit that shape to take so that they can have the interactions |
|
| 30:20 | need to have. And this is governed because of that plasma membrane. |
|
| 30:25 | , if you're looking at this picture , I don't know what the heck |
|
| 30:27 | looking at, that's okay, there's an electron micrografx and what they're |
|
| 30:31 | to say is that this is a of two cells side by side at |
|
| 30:35 | powers. So, it's really a picture. And if you look at |
|
| 30:40 | right there is the boundary between the cells. So, this little line |
|
| 30:44 | here is the cell membrane or the membrane of that cell. That little |
|
| 30:50 | , right there, is that So, that little space in between |
|
| 30:52 | is the interstitial fluid. All right , you're gonna hear me do this |
|
| 30:56 | in another class. Interstitial or the cells never really actually touch each |
|
| 31:01 | Interstitial fluid sits in between them. like you and your and your sibling |
|
| 31:05 | a car trip playing the I'm not you game. Did you ever play |
|
| 31:09 | ? Just like this? I'm not you you can't get mad because I'm |
|
| 31:13 | touching you. Right. And that's all cells are kind of doing. |
|
| 31:16 | not touching each other they've got that bit of space in there. And |
|
| 31:20 | we've done is we magnified that So now you can see there's the |
|
| 31:24 | space in between the two plasma And you can kind of see there's |
|
| 31:27 | characteristic when it comes looking at a membrane, it kind of looks like |
|
| 31:31 | lines, doesn't it? In the ? See here, See the two |
|
| 31:37 | . See the two lines. All . And now, you know where |
|
| 31:40 | going right. Plasma membranes are made of phosphor lipids in what is called |
|
| 31:48 | lipid bi layer. And all of sudden you flashback to freshman biology and |
|
| 31:53 | , oh my goodness, he's back freshman biology. Yeah, I |
|
| 31:58 | All right now. The unique thing plasma membranes. And it feels like |
|
| 32:02 | kind of going along, we're just of making the turn and we're gonna |
|
| 32:05 | back to the compartmentalization a second. , plasma membranes are sorry not plasma |
|
| 32:10 | membranes are made up of lipids and embedded with proteins or proteins are associated |
|
| 32:15 | them as well. Some carbohydrates, it's the primary component of the plasma |
|
| 32:20 | are these fossil lipids arranged in this bi layer. And so this is |
|
| 32:24 | another textbook. And you can kind see here is a fossil lipids there's |
|
| 32:27 | layer of phosphor lipids and they arrange in this organization. This by layer |
|
| 32:33 | the tails remember are are non And the heads are polar. And |
|
| 32:39 | if I'm polar, I wanna hang with water because water likes me. |
|
| 32:43 | if I'm non polar, water excludes . Have you ever heard that term |
|
| 32:47 | exclusion? You know, we always that that it's the tales that are |
|
| 32:51 | themselves. No water is like go . And so it makes the head |
|
| 32:55 | around so that the polar head is towards the water. And if you |
|
| 32:59 | enough of these fossil lipids, that's they do. They kind of arrange |
|
| 33:02 | like this. All right now, I said, there's some proteins in |
|
| 33:08 | and really the ratio of proteins to amount of fossil lipids actually a really |
|
| 33:12 | indicator. Generally speaking of the type activity or the degree of activity that's |
|
| 33:17 | place in the cell. So, this sells a really active cell, |
|
| 33:19 | gonna see lots of proteins embedded in membrane. All right now, the |
|
| 33:25 | can be found pretty much anywhere. can be found on the outside. |
|
| 33:27 | can be embedded uh through the through plaza memory. And they can be |
|
| 33:32 | on the inside. Alright. And got special names for all those |
|
| 33:36 | But first, let's focus here. , we've always learned that the plasma |
|
| 33:42 | is fossil lipids. But it's more just fossils. There are three basic |
|
| 33:46 | of fats that are found in a membrane. First one is the fossil |
|
| 33:52 | . So, here's the shape you kind of see here what we've |
|
| 33:55 | We've got our glycerol backbone, we to fatty acid tails. And then |
|
| 33:58 | that third carbon in that, in glycerol backbone, we have a phosphate |
|
| 34:03 | sort of weird polar head. All . That's the general structure. And |
|
| 34:08 | this is the portion that arranges itself from water that gets excluded from |
|
| 34:13 | And that's why we get this particular . Now, I don't know if |
|
| 34:18 | explain this here on another slide. gonna explain it here. So, |
|
| 34:22 | the cell or sorry, these these are not attached to each other. |
|
| 34:27 | basically like the way you guys are right now. If I told you |
|
| 34:31 | everybody get up and rearrange yourselves, can kind of get up and move |
|
| 34:34 | each other and do that. They that all the time. They are |
|
| 34:37 | what we call that fluid mosaic It's kind of like a waterbed where |
|
| 34:41 | is attached to each other. But all staying on the same side because |
|
| 34:45 | doesn't take a lot of energy to around on one side. But it |
|
| 34:48 | a ridiculous amount of energy to flip one side to the other. |
|
| 34:52 | that's a very rare occurrence for that occur. All right now. As |
|
| 34:59 | said, you're most familiar with this , I'm gonna go to the next |
|
| 35:03 | and I don't want you to All right. Your job is not |
|
| 35:08 | memorize names of molecules. Unless I .1 out and say you should know |
|
| 35:12 | molecule. Okay, but what you here, these are four of the |
|
| 35:17 | most common phosphor lipids. And I'm 40.1 out to you again. You |
|
| 35:22 | need to memorize this woman to point out because you will see it over |
|
| 35:24 | over again. You're like, thank you for pointing that out. |
|
| 35:28 | in looking at these, do they have the same features? Right. |
|
| 35:32 | . So conceptually when you see this , you should probably think phosphor |
|
| 35:36 | right? Always two tails. Glycerol, backbone, phosphate, |
|
| 35:41 | phosphate. And there's something weird going up top. Right? So that's |
|
| 35:46 | that's a feature that all fossil lipids . And if you ever see |
|
| 35:49 | you should go, that's probably a lipids. All right, now, |
|
| 35:53 | gonna point this one out to you here, fossil title settle because you'll |
|
| 35:58 | that one over and over and over . I'm not asking to memorize |
|
| 36:01 | I'm not asking to be able to it. I just want you to |
|
| 36:04 | the name. Okay, so when pops up again, cause I'm not |
|
| 36:07 | ask you a question on the test what is the one that I wanted |
|
| 36:09 | to learn? Because that's not a . That's just one of the things |
|
| 36:12 | wanted. I just want you to that because I'm gonna show you a |
|
| 36:15 | a little bit later. I'm gonna you a word another bit later, |
|
| 36:18 | it comes back to this molecule. so you can imagine a phosphor lipid |
|
| 36:22 | layer has these different types of molecules there. They're not all the |
|
| 36:27 | They have different polar heads. So means that they have different chemical |
|
| 36:32 | What does that mean? They play role in different types of chemical |
|
| 36:38 | And these fossil lipids aren't just sitting going it's kind of cool. Now |
|
| 36:44 | they're active in that lipid bi layer well. Now, if you look |
|
| 36:49 | these two things looking at that doesn't look like a fossil lipid? |
|
| 36:55 | but it's not all right. this is why I say when we |
|
| 36:58 | the shape, we should kind of that looks like a possible lipid. |
|
| 37:01 | it's not This is actually called a lipid. Alright. And what you |
|
| 37:05 | see here, it has a sting scene, Right? So this is |
|
| 37:08 | actual thing. So, there's no backbone. But it looks a lot |
|
| 37:11 | a glycerol with a fossil lipid attached a lipid or fatty acid attached to |
|
| 37:15 | . Instead, here's the fatty So, it says long chain with |
|
| 37:18 | fatty acid attached to a different And if you go back and look |
|
| 37:21 | it close enough, you'll be able see the difference is I'm not interested |
|
| 37:24 | pointing it out. All right. again, you have something unique on |
|
| 37:28 | top. But it looks a lot it. And so if it looks |
|
| 37:31 | it is going to behave like a lipid. And typically what these single |
|
| 37:36 | uh single lipids do is they kind congregate together. Kind of like |
|
| 37:40 | like have you noticed that people kind hang out things that kind of look |
|
| 37:44 | them or or act like them or like them, Right. And so |
|
| 37:48 | kind of do the same thing and form what are called lipid. You |
|
| 37:52 | take a class, like a cell where they talk about the lipid |
|
| 37:54 | that's the lipid raft molecule right there they kind of hang out and they |
|
| 37:59 | out together and particular proteins kind of out with them. And they kind |
|
| 38:03 | create these structures that kind of roam on the surface of the cell as |
|
| 38:08 | group. That's another example of a type of lipid. And the third |
|
| 38:13 | is one that you're familiar with you've about and everyone's told you it's |
|
| 38:16 | You should never have it in your . It's bad for you. |
|
| 38:18 | icky, icky. No, it's lie. You desperately need this in |
|
| 38:21 | body. It's cholesterol. All right , I'm not suggesting going over to |
|
| 38:26 | waffle house and ordering an extra side cholesterol to guzzle. That's not what |
|
| 38:30 | should be doing, but cholesterol is , really valuable, not just for |
|
| 38:36 | layer, but it's valuable for other of your body, all of your |
|
| 38:40 | start off as cholesterol and so if making steroid in your body, whether |
|
| 38:44 | a mineral kordech, oid or glucocorticoids an androgen which is testosterone, or |
|
| 38:50 | you're talking about estrogens or progesterone, all start off as this molecule right |
|
| 38:54 | cholesterol. Alright, now, what does because it's a fat is that |
|
| 39:00 | hates being in watery environments. if it can't be in a water |
|
| 39:04 | , it's gonna find wherever there is . And guess what? We got |
|
| 39:07 | in every one of ourselves because we these lipid bi layers. And so |
|
| 39:11 | it does, it likes to find way into a lipid bi layer and |
|
| 39:13 | itself there. Now, the reason able to do that is because of |
|
| 39:17 | way the fatty acid tails work. right. And I don't want to |
|
| 39:21 | into all the details of fatty But basically you could have saturated tails |
|
| 39:26 | will give you straight tails or you have unsaturated tails and give you a |
|
| 39:29 | kinks in your tails, right? if you get a saturated tail next |
|
| 39:34 | another fox Phillip that has a kink it, you now have a space |
|
| 39:38 | space at the molecular level means you fluidity. And if you don't have |
|
| 39:43 | , that means you don't have So think about butter for a second |
|
| 39:47 | is kind of solid, isn't It's made up of a whole bunch |
|
| 39:50 | fatty acids, really triglycerides. And triglycerides have a whole bunch of saturated |
|
| 39:54 | and and that's why you have a . But if you look at something |
|
| 39:57 | an oil like canola oil or coconut or cocoa butter or whatever, you |
|
| 40:03 | , just oil of some sort. basically a whole bunch of triglycerides that |
|
| 40:07 | those strange kinks in them. So they're not close together. And |
|
| 40:12 | got this fluid environment. Why cholesterol important is because when it inserts itself |
|
| 40:17 | that membrane, it does two things behaves or causes those lipids to behave |
|
| 40:24 | . So basically what you're doing is filling the gap. If I fill |
|
| 40:27 | the gap, then a fluid environment of becomes more solid nature. And |
|
| 40:36 | a more solid environment when that cholesterol in there and wiggles its way in |
|
| 40:41 | two very, very straight saturated fatty creates kind of a liquid environment. |
|
| 40:47 | so what that does for yourselves is allows them to be maintained at temperatures |
|
| 40:53 | they normally wouldn't be allowed to be at. So if I took you |
|
| 40:57 | put you at minus 80 degrees, freeze like, like that, that's |
|
| 41:01 | bad. Right? But if I you at minus 20 what do you |
|
| 41:05 | this degree Celsius, what do you ? Alright. You shiver and you |
|
| 41:10 | frustrated and you're angry. But do cells start dying on you? |
|
| 41:14 | because the cells don't solidify, they're to maintain their plasma membranes. If |
|
| 41:20 | put you out in the desert in , I don't know. Death |
|
| 41:23 | Or in Saudi where it's 100 and degrees in the shade. Are you |
|
| 41:27 | to melt? Maybe mentally. But cells are like, okay, I'm |
|
| 41:33 | gonna fall apart like butter does. gonna stay solid because of the cholesterol |
|
| 41:39 | that membrane. So, what it , it disrupts how those fossil lipids |
|
| 41:44 | and creates greater flexibility in those environments you'd lose the flexibility and create stability |
|
| 41:51 | those environments where you'd lose that Alright, alright. So, platinum |
|
| 41:59 | made up of lipids, they're made of proteins and they're gonna have sugars |
|
| 42:04 | there as well. We have three so far. 1st 1 is the |
|
| 42:10 | Lipids. 2nd 1. 3rd Good. All right. Now, |
|
| 42:17 | we're doing is we're shifting over to membrane proteins. Remember, I'm still |
|
| 42:20 | be coming back to that whole electrical . Right. I know you're |
|
| 42:23 | when is he gonna do this? don't know when the slide tells me |
|
| 42:25 | . All right. So, with to the proteins, there's different arrangements |
|
| 42:31 | these proteins and they have different functionality . But what we do is first |
|
| 42:34 | look and ask the question, how they arranged? I'm gonna start with |
|
| 42:36 | Middle one. What is an integral ? An integral protein is integrated into |
|
| 42:41 | membrane? Right. Typically what you to them as or you'll see them |
|
| 42:44 | to as this trans membrane proteins. means they cross completely through the lipid |
|
| 42:50 | layer and then come out the other to do something. And what you're |
|
| 42:54 | now with that protein which is now between those lipids is you've now allowed |
|
| 43:02 | created something that works on the outside communicates on the inside. Alright, |
|
| 43:09 | , that's kind of nice. So what we said. This plasma membrane |
|
| 43:11 | a role in communication. So this one of the ways that things can |
|
| 43:16 | communicated now. We can anchor them things. It doesn't matter what, |
|
| 43:20 | we can anchor them and hold them place. They can roam around the |
|
| 43:24 | membrane just fine. And there's a bunch of different types and they're classified |
|
| 43:29 | on the types or the numbers of membrane proteins or transmit brain sections. |
|
| 43:33 | like you'll see things like integration which have like a single trans membrane region |
|
| 43:38 | you'll see molecules that have the most one that you'll hear is the seven |
|
| 43:43 | membrane region which are like many receptors that's a specific type of orientation to |
|
| 43:50 | now attached to these. You can proteins see right there and right |
|
| 43:54 | those would be peripheral proteins. so they're loosely attached to the integral |
|
| 43:58 | . They're not violently linked their associated them and they can do stuff and |
|
| 44:03 | you can have them. There can enzymes that can be binding proteins. |
|
| 44:06 | found on the inside or inside or outside. But they're there to allow |
|
| 44:12 | some sort of metabolic activity to All right. And then we have |
|
| 44:17 | really weird ones. Either the lipid ones. So right here um you |
|
| 44:22 | see that we have a phosphor lipid phosphor lipid has a sugar chain and |
|
| 44:30 | that sugar chain at the end is associated or affiliated with one of these |
|
| 44:35 | . That would be an example of lipid anchored. Alright. And |
|
| 44:40 | what are they associated with those weird ? This finger lipids, they help |
|
| 44:45 | those lipid rafts. Alright, depending who you're talking to, they might |
|
| 44:49 | them an integral protein. But in because because you can't break them apart |
|
| 44:56 | easy. But in essence this is of the ways that we can have |
|
| 45:00 | protein associated with a membrane. It have to be inserted in. It |
|
| 45:05 | be associated with that foster lipid kind weird. Now again I said they |
|
| 45:13 | a whole bunch of different jobs So, here's an example of |
|
| 45:17 | This would be one of those seven membrane ones. But this is what |
|
| 45:20 | refer to as a ligand binding receptors a generic term. Alright, you |
|
| 45:25 | ever heard of the G protein coupled is an example of one. |
|
| 45:29 | We're going to see an example and say you know how many g protein |
|
| 45:32 | receptors you have in your body? want one a lot? Yeah, |
|
| 45:35 | the good answer. It's about And the reason you have about 4000 |
|
| 45:39 | your nose has about 4000. And then there's like maybe another 100 you |
|
| 45:43 | ? So the way that you detect is primarily through g protein coupled receptors |
|
| 45:49 | , couple on your tongue as but there's only again about another |
|
| 45:52 | Alright. Now, the way this is you can see you have a |
|
| 45:56 | binding domain, this is gonna be of side of the cell that you |
|
| 45:59 | these trans membrane regions, you can how it's kind of arranged in this |
|
| 46:03 | . And then on the other side have a cytoplasmic region. So if |
|
| 46:07 | binds up here, it changes the of this molecule which the interaction of |
|
| 46:12 | tale with whatever it's interacting with and changes activity inside the sale cell. |
|
| 46:18 | , this is an example of how works from outside to inside. |
|
| 46:23 | I didn't have to go inside the to do something. I worked between |
|
| 46:26 | two environments using this trans membrane That would be an example of one |
|
| 46:32 | makes sense so far. Yeah. . These will also play an important |
|
| 46:37 | in vesicular transport. We'll get there we get there. Alright, here's |
|
| 46:42 | one. Adhesion molecules. What do think? Adhesion molecules? Do you |
|
| 46:46 | stuff? That's right. It's molecular is the best way to think about |
|
| 46:50 | . Um How many here are younger did you guys ever get indian |
|
| 46:57 | Okay. How many of you are siblings? Did you ever give an |
|
| 47:01 | burn? Yeah, I was an sibling to pink bellies. Wet |
|
| 47:09 | And the indian burn, you know the indian burn is? You do |
|
| 47:13 | for I'm gonna demonstrate, I'm not demonstrate, but it's basically you get |
|
| 47:16 | and you grab them and you twist opposite directions. Yeah. Right |
|
| 47:23 | you know what I'm talking about? don't know, maybe had a different |
|
| 47:25 | for it. We called them indian . Alright, now, when I |
|
| 47:29 | that or when someone does that to or you do it to somebody |
|
| 47:33 | why does your skin not come falling ? I mean it feels like it |
|
| 47:37 | , but why doesn't it? Its , it is tight junctions, it |
|
| 47:44 | . I mean, it's actually Desmond's and hemi Dismas OEMs. But what |
|
| 47:48 | doing is you're using adhesion molecules at at that foundation. All right. |
|
| 47:55 | so basically you have cells that are with each other and are being held |
|
| 48:00 | by adhesion molecules so that when you on one it pulls on the next |
|
| 48:04 | , which pulls on the next which pulls on the next one and |
|
| 48:07 | the force of energy. This is cells are attached to each other? |
|
| 48:11 | right, that's the easy way. some of them may be G. |
|
| 48:14 | . I linked So they're anchored to fossil lipid. Alright, you |
|
| 48:19 | Which phosphor lipid do you think they linked to G. P. |
|
| 48:30 | There you go. Gp faucet title settle. All right. That's just |
|
| 48:34 | example of no. Because it's a word. Its phosphate title. And |
|
| 48:41 | the first one in the line. , you do not need to memorize |
|
| 48:43 | . It's not gonna be on the . I'm just trying to show you |
|
| 48:47 | you're gonna start seeing these things pop . It's like you know when you |
|
| 48:49 | looking for a car and then you noticing your cars everywhere. Right? |
|
| 48:53 | you know that's that's kind of the thing. It's like I pointed out |
|
| 48:56 | you. I'm just gonna keep pointing to see There it is. |
|
| 48:58 | there it is again, there it again. Yeah. You know? |
|
| 49:02 | in this case the G. I remember this is to foster |
|
| 49:04 | So what it is is it's a elated phosphor lipid attached to a protein |
|
| 49:10 | that protein now is interacting with the cellular matrix. Now in this particular |
|
| 49:15 | , we're trying to show you to that are um And again, you |
|
| 49:18 | need to know that those are But they're basically showing these two immigrants |
|
| 49:22 | are interacting with an extra cellular If you've ever heard that word. |
|
| 49:26 | cellular matrix. You don't know what means. It means. There's a |
|
| 49:28 | bunch of proteins that sits outside of cells as a matrix of proteins. |
|
| 49:32 | of like a cloud around the cell you get to attach yourself to it |
|
| 49:36 | kind of holds you in place. cell has this stuff. It's |
|
| 49:40 | very interesting when you start diving down like again again, think about the |
|
| 49:44 | school picture of the cell that you and then you start looking at how |
|
| 49:47 | real cell is like, oh my , how do we ever know |
|
| 49:51 | So this is just an example. we have receptors right, trans that |
|
| 49:57 | that we as one type. We adhesion molecules as another type. |
|
| 50:01 | not specifics, we're not looking at molecules. We have transport molecules and |
|
| 50:06 | a whole variety of transport molecules. , generally speaking, when you talk |
|
| 50:10 | transport molecule, their job simply is allow a molecule to move from one |
|
| 50:14 | of the membrane to the other. kind of like the door back |
|
| 50:17 | right? If this is the inside cell and that's the outside of the |
|
| 50:19 | . The doorway is kind of like transport molecule. Now, in this |
|
| 50:23 | case, if you look at the , you can all turn around and |
|
| 50:26 | the doors open or closed. Right they're open. So these are behaving |
|
| 50:30 | of like pores anything can wander in out, right? If I want |
|
| 50:34 | prevent things from wandering in and What would I do And close the |
|
| 50:38 | ? Right. And so once you that, what what we have now |
|
| 50:41 | a different structure, what we refer as a channel. Alright, now |
|
| 50:46 | All right, these are these are . Is that I don't know why |
|
| 50:49 | picked channel over door over something but it's a channel. And so |
|
| 50:53 | it does, it just allows materials pass from one side or the |
|
| 50:56 | Now, if I have lots of over here and very little potassium over |
|
| 51:00 | and I've got a channel in between . Which direction is the potassium gonna |
|
| 51:03 | high to low. Alright, so are certain rules, physical laws that |
|
| 51:09 | are gonna follow. Alright, so are are specific to what they allow |
|
| 51:14 | pass through. But molecules that are through them are gonna follow their concentration |
|
| 51:19 | , downhill carrier protein on the other , are a little bit different and |
|
| 51:24 | are gonna be open or closed. , so poor is what we call |
|
| 51:27 | when it's always open. A channel can open and close. Generally |
|
| 51:31 | carriers and pumps are a little bit . We're gonna go in a little |
|
| 51:35 | more detail about this a little bit . But here what we have is |
|
| 51:38 | literally bind the molecule that they're So if a channel is something that |
|
| 51:43 | these doors where you open and close , a carrier is more like one |
|
| 51:47 | those doors at a hotel that right? Because there's a point when |
|
| 51:51 | go through that door, right, like on the outside and then you |
|
| 51:55 | in and then it kind of turns now you're not on the outside and |
|
| 51:58 | not on the inside yet, you at that point, and you kind |
|
| 52:01 | get that little panic in your like hopefully this will keep going and |
|
| 52:04 | you got your luggage, you're okay, I really got to do |
|
| 52:06 | . And then you get onto the side and it's like now I can |
|
| 52:09 | out and that's kind of what a is. It binds to the agent |
|
| 52:13 | it's moving. And then when it it it changes the shape of the |
|
| 52:17 | . And now that molecule can move the other side for a carrier molecules |
|
| 52:22 | moving down the gradient for pumps, has an implication there, right, |
|
| 52:29 | using energy so I'm moving things against gradient. Alright, so again, |
|
| 52:35 | just use potassium and making up a at this point. I got lots |
|
| 52:38 | potassium over here and I've got a potassium over here, but I've got |
|
| 52:41 | pump. So potassium is going to pumped from this side to that side |
|
| 52:45 | that side to this side. He's go from small to large, you're |
|
| 52:51 | against the gradient in a direction, doesn't want to go. So when |
|
| 52:55 | hear the word pump, I'm moving against the direction they want to go |
|
| 53:01 | they want to go into the cell this particular case would be pushed |
|
| 53:05 | All right. So energy here and this energy is coming from. It's |
|
| 53:10 | be from the hydraulics of 80 either directly or indirectly. And we're |
|
| 53:14 | go into that more details in just second ones. Oh, we have |
|
| 53:19 | that are involved in intracellular signaling. this is just an example. Here's |
|
| 53:23 | G protein coupled receptor, there's the protein you activate the G protein you |
|
| 53:27 | not need in all these steps We'll get to it when we get |
|
| 53:30 | it. But you can see that a series of molecules that are associated |
|
| 53:34 | this pathway that are associated with the . Okay. Yeah. Alright. |
|
| 53:44 | again, a channel is a structure allows things to just flow through. |
|
| 53:48 | no energy involved. Right? So channel in a very unrestricted way could |
|
| 53:53 | opened or closed. Right? And is specific. But what it is |
|
| 53:57 | that once you create it creates an pathway between the two. Remember, |
|
| 54:01 | the carrier, what you're doing is binding the agent, you're changing the |
|
| 54:04 | of the molecule and moving it. not gonna say through you because that's |
|
| 54:07 | entirely accurate but it's kind of Okay, that's correct really. And |
|
| 54:15 | gonna get to this in just a . But I'll just I'll just tell |
|
| 54:18 | now why not a channel basically is open tube that has a specific amino |
|
| 54:23 | with specific charges. So it's kind like sending a pinball through like a |
|
| 54:28 | field and it kind of jerks its through because it has the right uh |
|
| 54:32 | on it. That's the best way describe it. So, these things |
|
| 54:40 | here, these two molecules notice that they have their little edges poked in |
|
| 54:45 | . So they're they're associated with the . So some of the plasma |
|
| 54:50 | you'll see and I'll come back. of the plasma membranes you'll see here |
|
| 54:54 | gonna be associated on the inter cellular and play a role in metabolism that's |
|
| 54:58 | place at the membrane. Okay, ahead. Sorry, I'm going |
|
| 55:02 | Right. Uh huh, carriers. . So so here when we talk |
|
| 55:10 | a carrier, what we're saying is this is a passive ability and we're |
|
| 55:14 | we've got another slide, We're gonna back and I'm gonna look at |
|
| 55:16 | So you're not dependent upon energy. it takes is the binding of the |
|
| 55:20 | . And that binding of that molecule the change the shape. It's like |
|
| 55:25 | somebody's hand. This is the shape my hand. Right? And when |
|
| 55:27 | shake hands, my hand changes And now I'm doing a different |
|
| 55:31 | Right? And that's kind of what carrier does. It's changing shape by |
|
| 55:35 | of it binding to the molecule that's of binding it. The pump does |
|
| 55:40 | same thing it binds but it can't the molecule because it needs that energy |
|
| 55:45 | drive it the other direction. Yes. So it is an active |
|
| 55:51 | . And what we're gonna see is there's two forms there's a there's a |
|
| 55:54 | and then there's an indirect. So are always going to catalyze reactions. |
|
| 56:01 | what you're looking up here, that right there, that's phosphor light pace |
|
| 56:05 | see the enzyme they're like pace. phosphor light paste. See. |
|
| 56:11 | And so its job is to catalyze enzyme or catalyze a reaction on the |
|
| 56:15 | of the membrane here. Again, is one of those pictures I want |
|
| 56:18 | to look at. Do you do see up here the pipe too? |
|
| 56:23 | see the i. p. Fosse fosse fatal. So sorry, |
|
| 56:30 | . Title in a hospital from an reaction gets converted to foss foss fatal |
|
| 56:36 | . Eight hospital di phosphate pIP two then it gets another phosphate. |
|
| 56:42 | It's broken in half given another phosphate . p. three and also tall |
|
| 56:48 | . Alright again, do you have know that? Don't don't don't don't |
|
| 56:51 | the scrunchie. I don't you don't to memorize this. I'm just pointing |
|
| 56:54 | out so very often when we look these membranes, we look at them |
|
| 56:58 | we just think that they're just sitting passively. Alright. I want to |
|
| 57:01 | out that it's not that they're just there passing. They play major roles |
|
| 57:05 | signaling molecules. They play these fossil play major roles in metabolic activity. |
|
| 57:11 | served as signaling molecules. And like is an example. It's serving as |
|
| 57:14 | signaling molecule. You cleave it. then over here it's serving to activate |
|
| 57:18 | else. All right. Oh. if you haven't taken cell biology or |
|
| 57:23 | biology yet, just start getting used the uh the alphabet soup of |
|
| 57:27 | That's just the nature of these It's you saw me. I'm struggling |
|
| 57:32 | foster and foster. A title and foster title and it'll die phosphate |
|
| 57:39 | Too much easier. Right PLC is easier than fossil like pay C. |
|
| 57:45 | . If you have a Foster like , what do you think the chances |
|
| 57:47 | you have a fossil like being a like they say. What do you |
|
| 57:52 | ? Pretty good. Okay. So speaking when you see an A or |
|
| 57:55 | alpha or something like that, there's a beta or a B. If |
|
| 57:59 | see a one there's probably a I'm just giving you a heads up |
|
| 58:02 | what you're getting yourself into. All . Anyway. And then last |
|
| 58:07 | Other proteins can be parts of these side of skeletons. When you hear |
|
| 58:11 | word side of skeleton. What does mean? It means cell skeleton. |
|
| 58:16 | . So basically it creates that mesh or that network to allow the cell |
|
| 58:20 | have the shape to be able to the thing that is designed to |
|
| 58:23 | it also helps to organize the plasma . Alright, helps to organize what's |
|
| 58:28 | where and why? So, what going to see very often is you'll |
|
| 58:31 | cells like epithelial cells that are organized a pickle side and the basil |
|
| 58:36 | And so the proteins that are supposed be on the a pickle side are |
|
| 58:40 | to be limited by where that side skeleton is. And it basically |
|
| 58:43 | oh you proteins you stay up here remember fluid mosaic model, I can |
|
| 58:48 | wherever I want to and by creating barriers, you're like, okay, |
|
| 58:52 | limited, you can go wherever you over here, but you're limited to |
|
| 58:55 | top. You can't go down to bottom. Alright. That would be |
|
| 58:59 | example of these plasma membrane proteins. then like I said, there's carbohydrates |
|
| 59:05 | just to make things even more So proteins and lipids can have sugars |
|
| 59:09 | to them. We already saw kind a picture of that. Alright, |
|
| 59:12 | that's when you hear the word glycoprotein lipid. What you're saying is I've |
|
| 59:17 | a protein or lipid that has a chain that hangs off the side and |
|
| 59:21 | cell uses this kind of the way self identify, right, is |
|
| 59:26 | oh my sugar chains look a very way. That's this cell right here |
|
| 59:31 | to me. Alright. So that's of the things that it's used |
|
| 59:34 | All right. And so collectively refer all of the sugars. Whether they're |
|
| 59:40 | glycol lipids, That arrangement around the is referred to as the glycol |
|
| 59:45 | So, when you hear that word just referring to all the sugars. |
|
| 59:49 | , ladies, when your mother's told your sugar and spice and everything |
|
| 59:53 | they weren't lying. There's no snakes snails and puppy dog's tails though. |
|
| 59:58 | , I don't know what to do the guys. Alright, So, |
|
| 60:03 | gonna pause here for a second. gonna take a sip. What questions |
|
| 60:06 | guys got for me now. you can tell I talk fast. |
|
| 60:11 | . Anyone? Yes. Go Oh, are they? Um So |
|
| 60:26 | right. So, I think the you're asking me and you just tell |
|
| 60:28 | like, no, by your I missed it you're asking me. |
|
| 60:31 | like, do carriers change shape? enzymes change shape? That's that's |
|
| 60:38 | No, not necessarily. Um I All right. So I say that |
|
| 60:44 | I'm saying as an external so the can be an enzyme itself. All |
|
| 60:50 | . So, for example, the we're going to look at in just |
|
| 60:52 | moment is the sodium potassium 80 Ace right now notice it's an ace |
|
| 61:00 | it's gonna be cleaving A. P. It's not an enzyme coming |
|
| 61:04 | and saying all right, I'm gonna remodel the shape of this just simply |
|
| 61:08 | the virtue of it interacting with that ion causes the natural molecule change |
|
| 61:15 | Okay, Does that mean it won't . I'm not gonna I'm not gonna |
|
| 61:19 | that claim at all. Right. even if that were true right |
|
| 61:24 | I can guarantee there's probably a molecule my future that would do that. |
|
| 61:27 | one of you to come back 10 later. See it's right here and |
|
| 61:30 | be like, I don't know who are and what are you talking |
|
| 61:34 | Right. Any other questions? there are other things, but we're |
|
| 61:45 | really 100% sure what they do or . The only thing I truly know |
|
| 61:50 | , like, okay, Alex is everyone's like, okay, Alex is |
|
| 61:53 | even among identical twins. So, is it is something that the cells |
|
| 61:58 | using as a form of communication, know, contact communication beyond that. |
|
| 62:04 | it's not really quite clear. At as far as I know. I'm |
|
| 62:07 | if I went diving into the I'm sure there's probably somebody who's claimed |
|
| 62:11 | somewhere, but I don't know anything . Yeah. Sorry. All |
|
| 62:22 | You're gonna speak up a little I'm probably not helpful. Come on |
|
| 62:25 | other side. Okay. Well, , so typically speaking all proteins are |
|
| 62:35 | except when they're just allowed to be right. So, for example, |
|
| 62:39 | just gonna give you an example from so when I was in grad |
|
| 62:42 | the lab next door to me works on integrates? All right. That |
|
| 62:46 | was their job. They actually had of the really cool experiments because they |
|
| 62:49 | with Nasa. So they were like stuff up on the space shuttle to |
|
| 62:52 | stuff. Right? And one of things that they were using these immigrants |
|
| 62:55 | was to see the mobility of immune in a system. So you |
|
| 63:00 | your immune cells are in circulation all time. And what they do is |
|
| 63:03 | a signal comes along a signal, tell, hey immune cell, you |
|
| 63:06 | to stop here and infiltrate into this . All right. And so it's |
|
| 63:12 | like for example, these immune you can put them down on a |
|
| 63:15 | , put them at zero G. they would kind of walk around the |
|
| 63:20 | . Right? So the zero You basically spend it very slowly in |
|
| 63:22 | centrifuge. And what you could do you could tag those proteins with a |
|
| 63:27 | a die like a fluorescent dye and can take pictures on a regular |
|
| 63:31 | And what you'd see is you could like the proteins like when they're |
|
| 63:36 | they're stuck in position. Right? when that protein, when that when |
|
| 63:40 | when that cell moved like kind of a tank tread, you could see |
|
| 63:44 | protein over here and it would stay stuck stuck. And then when it |
|
| 63:48 | to the end of the cell and cell was rolling away, you find |
|
| 63:51 | the other side and it would be , it's racing to the other side |
|
| 63:53 | become the front end again, So when it was in adherence, |
|
| 63:59 | was associated with something to hold it place, but when it wasn't part |
|
| 64:04 | that adherence then it no longer had influencing where it was going to be |
|
| 64:08 | . So that characteristic of being bound or being you know, present prevented |
|
| 64:15 | moving is a part of the function the protein. So like we'll have |
|
| 64:19 | that are kind of loosey goosey but they get bound they will, they |
|
| 64:23 | attach themselves to the side of skeleton then associate say to a classroom coated |
|
| 64:27 | which is a word you guys have at least once in your lives. |
|
| 64:31 | , classroom coded pit, just nod head to say yeah of course, |
|
| 64:34 | know human or not human physiology I don't know if it was biology |
|
| 64:39 | , but Alright, did I answer question or did I just completely go |
|
| 64:43 | a different direction If I went in different direction, you just tell me |
|
| 64:47 | , you didn't answer my question, have no idea what you're talking |
|
| 64:50 | Okay, so so speak up a bit and again I would tell |
|
| 64:55 | just remember I'm used to being in large room so I'm used to projecting |
|
| 64:58 | voice, I know you guys aren't to projecting so no one is |
|
| 65:02 | I'm just gonna say no one is look at you and go you sound |
|
| 65:05 | an idiot. I see that look your face like no, he's lying |
|
| 65:08 | me over here. No. So so I can hear because oh peripheral |
|
| 65:16 | , That's c when I heard you I heard purple proteins and I just |
|
| 65:19 | like I knew what you were talking . This is why it's important to |
|
| 65:24 | up because I will make up words right with regard to peripheral proteins, |
|
| 65:30 | are always going to be associated to integral integrated protein on the trans membrane |
|
| 65:35 | to which they are designed to be to. Right? So they're not |
|
| 65:40 | switch between say trans membrane basically once create them, they're gonna bind up |
|
| 65:44 | what's what matches them. It's kind like we're doing the handshake if I |
|
| 65:49 | match up to you. If I'm designed to match up with you that |
|
| 65:51 | not gonna attach to you. So only gonna attach to what I'm specifically |
|
| 65:54 | to be able to attach to. then so the second half of your |
|
| 65:57 | was or did I just answer Okay. You sure? Okay, |
|
| 66:06 | don't want to walk out and you answer my question, you wouldn't listen |
|
| 66:08 | me. Alright. So we've been of talking a little bit about how |
|
| 66:14 | move, right? We've described that have these two environments and extra cellular |
|
| 66:18 | and intracellular environment and we said that have proteins. And we even kind |
|
| 66:22 | describe So the proteins that allow things move between these two environments. |
|
| 66:27 | one mechanism of movement inside the body called bulk flow. And basically bulk |
|
| 66:32 | is simply looking at all the constituents whatever the fluid is. Remember, |
|
| 66:35 | is a fluid, right? And asking the question of which direction is |
|
| 66:40 | pressure driving the material in that Alright. And so for example, |
|
| 66:45 | can think of like the respiratory system I breathe in, I'm pulling in |
|
| 66:51 | , right? What's an air And nitrogen and and and and and |
|
| 67:02 | and so that you can see it's just oxygen. Right? So, |
|
| 67:07 | though the only thing out of that list that you guys gave me, |
|
| 67:10 | only thing I want my lungs or my body is the oxygen, everything |
|
| 67:16 | with it because the pressure gradient drives material into the lungs. Now there's |
|
| 67:21 | exchange takes place in the lungs. then when I breathe out, what |
|
| 67:24 | I breathing out and and everything including oxygen and nitrogen and hydrogen and |
|
| 67:32 | and all the other fun things that to be in the air that we |
|
| 67:36 | even consider. All right, But just put it out a little bit |
|
| 67:40 | carbon dioxide. So, bulk flow of describes that movement. So, |
|
| 67:44 | you think about the plasma and the fluid, remember, we said they |
|
| 67:48 | , right? When the cardiovascular system pushing the blood through and when you |
|
| 67:52 | into these environments where they where the fluid and plasma can mix, there's |
|
| 67:57 | be a pressure gradient that drives fluid the plasma into the interstitial fluid. |
|
| 68:02 | then the pressure's going to build up the Internet a little bit further down |
|
| 68:05 | road, a couple of millimeters The pressure in there now drives the |
|
| 68:09 | back up into the cardiovascular system and doesn't care that you're carrying waste or |
|
| 68:14 | or not glucose or whatever it happens be in the blood, it's just |
|
| 68:18 | as a result of the pressure Alright, so that's one of the |
|
| 68:22 | that things move through the body. what we're interested in is knowing is |
|
| 68:27 | do I move things from the extra fluid to the inter cellular or vice |
|
| 68:32 | ? Right now, the membrane, we say is, you know, |
|
| 68:39 | we look at a memory, we the questions, right? If that |
|
| 68:41 | allows for the passage of a certain , we say that membrane is permeable |
|
| 68:45 | that material. If a membrane doesn't a material through it, we say |
|
| 68:50 | impermeable, and I know you're looking me going well duh dr wayne, |
|
| 68:53 | what those words mean. But it's important to make sure that we understand |
|
| 68:56 | . Because when we talk about the membrane, we say that it is |
|
| 69:00 | impermeable, Because now what we're doing we're talking about everything in the |
|
| 69:05 | Right. So, a plasma membrane be permissible to lipids, but it's |
|
| 69:10 | to ions. So, that membrane semi permeable, right? Because it's |
|
| 69:16 | permeable to different substances. All The other word we might use would |
|
| 69:21 | selectively permeable. I get to decide goes in my house. Right. |
|
| 69:28 | . Is that true for you Or you leave the door open and |
|
| 69:31 | anything can wander in raccoons? No. We are selective to what |
|
| 69:37 | allow in the house. If the comes to the front door and |
|
| 69:40 | may I come in, what do say? No. The rule The |
|
| 69:44 | is I think this is the rule you have to invite it in the |
|
| 69:48 | . That's what every movie has ever me. You have to invite the |
|
| 69:51 | in the house, otherwise he's stuck or she I've not seen a lot |
|
| 69:56 | them with women. Right. this selective permeability is going to be |
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| 70:03 | by the lipid and protein composition of plasma membrane. Alright, So, |
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| 70:11 | also have to have a you have To 10. All right. |
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| 70:15 | you gotta warn me to 20 is we're done. Right? So, |
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| 70:19 | I you gotta warn me to You gotta shut up dr Wayne. |
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| 70:23 | right. You got five minutes. that's where I'm gonna go like. |
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| 70:28 | right. Now to get things into cell, there's gonna be some certain |
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| 70:33 | . Alright, Every every molecule look you have to ask these questions. |
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| 70:37 | right. What is its relative Itty of that molecule? And lipid |
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| 70:40 | why? Why is that important? the plasma membrane is made up of |
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| 70:44 | ? Right? So, if you're soluble then in you go, nothing's |
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| 70:49 | stop you. Right? In other , the wall doesn't exist for |
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| 70:53 | In fact, the wall is where wanna go. It's like please just |
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| 70:57 | me in here away from all the . Right? If you're not soluble |
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| 71:01 | what you are is you're stuck either the outside or on the inside, |
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| 71:04 | on where you started from. So, some examples of that, |
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| 71:08 | a molecule like oxygen or carbon dioxide small and its uncharged. Therefore it |
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| 71:13 | lipid soluble. So you can just in oxygen and it will just flow |
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| 71:17 | the body and nothing can stop it moving to wherever it wants to |
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| 71:21 | Right, anything that's uh you basically a non polar molecule, like |
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| 71:26 | fatty acid fatty acid will come across plaza memory. Oh, this is |
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| 71:30 | these are my people. I can hang out with them. Things like |
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| 71:34 | on the other hand, I want hang out with water. And so |
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| 71:37 | membrane serves as a major barrier molecules are polar, like glucose serves as |
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| 71:43 | major barrier. So we have to mechanisms to bring those across size matters |
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| 71:48 | it comes to the size of a or two molecules movement. Alright, |
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| 71:52 | want you to think of yourself at concert or at a football game that's |
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| 71:56 | , Right? If you're a big like I am, you have to |
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| 72:00 | slowly, right? Because you're like around with everybody else. You're a |
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| 72:04 | object. And it's hard to get people if you're like one of my |
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| 72:09 | , right? You can run between legs, right and disappear and find |
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| 72:14 | way to the car before we ever there. That's never happened. |
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| 72:19 | So small molecules move easy. Big have difficulties. So, when you're |
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| 72:24 | about the movement of materials, even something is polar, if it's too |
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| 72:28 | , it can't get into the Excuse me. Non polar is what |
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| 72:33 | was looking for. The other you need some sort of force. |
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| 72:36 | what we do is we refer to use of energy and so we can |
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| 72:39 | there's passive movements. So you don't energy directly to do this. Like |
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| 72:43 | teepee. If it's active, then were you know, when we're talking |
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| 72:47 | is like gradients is what we're more in when it's passive, it's active |
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| 72:51 | , energy is going to be used either directly or indirectly to make that |
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| 72:56 | . All right. And so these the different types of transport. These |
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| 72:59 | the terms you'll hear. And so should be familiar to you. We |
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| 73:02 | diffusion. We have different forms of , like facilitated diffusion, active |
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| 73:08 | secondary active transport. We have the transport and we have osmosis. And |
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| 73:13 | is just kind of a slide to of give you that big picture, |
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| 73:16 | we're gonna talk about each of them and I only have 20 minutes and |
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| 73:19 | scaring me that I'm not gonna get where I want to go to |
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| 73:23 | Dammit. I got it. I . Alright, so diffusion is |
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| 73:29 | basically what it says is, look I've got a whole bunch of molecules |
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| 73:31 | are concentrated together, if I put into an environment where there's less |
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| 73:35 | all those molecules are gonna try to from each other and become equidistant from |
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| 73:39 | another. All right, that's something all learned at some point, given |
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| 73:42 | time, eventually that's gonna happen. that's what this is trying to |
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| 73:45 | So, basically the movement of the are moving down their concentration gradient until |
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| 73:51 | is reached. And there's lots of that apply to this and they were |
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| 73:55 | discovered by this guy named thick and figured this all out like in the |
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| 73:59 | . But there's just some rules like here's an example here we've got all |
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| 74:02 | molecules jammed up together and here's an where they don't have a lot of |
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| 74:06 | . And it's basically say there are molecules here running into each other because |
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| 74:09 | the kinetic energy and they start bouncing each other until everyone's bouncing into each |
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| 74:13 | equally. What that means is that are molecules moving this direction. There |
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| 74:17 | molecules moving that direction. There just to be more molecules moving that |
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| 74:21 | So the net diffusion or the net is moving from area A to area |
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| 74:26 | down the concentration gradient. Now, do we speed this up? We're |
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| 74:32 | just use some simple, we can how do we slow down? But |
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| 74:34 | just gonna look at the one The higher the concentration, the faster |
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| 74:38 | gonna move. If I'm on a , I'm on a slope like |
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| 74:41 | Am I gonna move fast or slow I'm on a skateboard, an amount |
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| 74:45 | slope like this fast or slow So the steeper the concentration gradient, |
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| 74:49 | faster I go, That's an easy . Alright, shorter distances. If |
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| 74:53 | only have to go from here to , I can move fast. But |
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| 74:56 | I have to go here to over , it's gonna take longer. |
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| 74:59 | if I'm diffusing over a distance, just need to know is at a |
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| 75:02 | distance or long distance, shorter distance , I can move faster, higher |
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| 75:07 | . What is temperature, It's it's kinetic energy. Right, So |
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| 75:12 | kinda have to wrap our mind around that we're talking about kinetic energy |
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| 75:15 | So if I impart more kinetic energy those molecules, they're gonna start bumping |
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| 75:19 | each other faster and thus equal, a lot easier example. I like |
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| 75:24 | use is sweet tea. Right? here know how to make sweet |
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| 75:28 | You boil your t you put in sugar while it's still hot. And |
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| 75:32 | does the sugar do? It dissolves equal liberates. Right. If I |
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| 75:36 | to the restaurant, order an iced , they bring a bitter tea and |
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| 75:39 | they give me the sugar, the substitute. I put it in there |
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| 75:42 | I have to spend all the rest the day stirring it, supplying kinetic |
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| 75:48 | in order to get the equilibrium temperature energy. And lastly the smaller molecule |
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| 75:56 | . All right. So this is gives you the same thing. It |
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| 75:59 | in the surface area. So in words, you know, what's the |
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| 76:03 | you know steepness? What is the of the membrane towards the thing that |
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| 76:07 | looking at? If I throw that in there, what is the surface |
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| 76:11 | ? Right. So how many people you think we can fit through that |
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| 76:14 | at a time? I'm looking at but I'm a big guy. |
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| 76:20 | three of three of me could not through that door at the same |
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| 76:23 | Right. So what do I have do? I have to go side |
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| 76:28 | . Alright, so three people Okay, so but if I want |
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| 76:31 | get more people through that door, do I have to do? |
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| 76:35 | I have to open. I have swing the other side open. |
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| 76:37 | So, at that point then, have I done? And I've increased |
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| 76:40 | surface area of that space. That's kind of what that's saying. |
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| 76:44 | And then thickness of the membrane you're not gonna see a lot of |
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| 76:47 | in that. But basically, if looking at that, that's the thickness |
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| 76:50 | the membrane, here's that slide. . Look how many slides it took |
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| 76:55 | get there. All right. And math. All right. Really? |
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| 77:00 | this says is, look how does move? Remember what we said is |
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| 77:04 | are particularly ions They have chemical gradients then they also have this electrical |
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| 77:09 | These two gradients oppose one another. there's a point where that molecule, |
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| 77:14 | every molecule that's moving in one direction taking with it. It's charged And |
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| 77:18 | gonna be a point. And that gets over here where it's like |
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| 77:21 | no, no. I want to back the other direction. Right? |
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| 77:24 | so there's gonna be a point where molecule is playing the field where it's |
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| 77:26 | to go this way. Now I that way, I'll go this way |
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| 77:29 | you've reached that equilibrium. Alright. can figure that out for every single |
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| 77:34 | using the first equation, which is this horrible thing is right here calculated |
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| 77:38 | . All right. And so that equation tells you why those particular items |
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| 77:44 | we looked at our at those relative were at. We're not gonna have |
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| 77:49 | memorize those numbers yet. We're gonna back to them when we start talking |
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| 77:52 | the electrical abilities of these membranes. right. If you're talking about an |
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| 77:57 | substance, the thing that doesn't have electron basically the rate of flux. |
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| 78:02 | other words, the diffusion, the of flux, the rate of diffusion |
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| 78:05 | the flux is gonna be just based its concentration gradient. So, if |
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| 78:09 | got a lot of something that doesn't a charge, it's just gonna go |
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| 78:12 | fast as it allows. But if have something that has a charge, |
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| 78:15 | gonna find a point of equilibrium between electrical and the chemical man, I |
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| 78:22 | not get where I wanted to How much time? One minute. |
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| 78:28 | my goodness. Alright. I think will stop there because these kind of |
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| 78:32 | together and I can get to my better. All right, before you |
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| 78:37 | running out of here because I know think are there questions? Of course |
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| 78:42 | are because I talk fast. But . Okay, collect your question, |
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| 78:51 | that? I think I am I know for certain. Okay, so |
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| 84:41 | gonna be a bunch of dead space the end. Actually, let's go |
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| 84:43 | here so I can just stop this . Um Yeah, it would be |
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| 84:48 | if I stopped |
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