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BIOL 2301 Human Anatomy & Physiology I - 2301_lecture04_0609
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00:03 it started here, um three of in the front. Your job is
00:08 watch that orange light, not the time. If he goes out,
00:12 me know, Okay, um it be charged, but I don't I
00:16 know. So, today is kind one of these days that for
00:21 it's exciting, this is the type stuff I live for. This is
00:24 I stayed in school and stuff like for you guys. It's probably gonna
00:28 a little boring. Don't you love when a professor tell you the class
00:30 going to be boring? Yeah, we're gonna do is we're gonna look
00:34 uh some physiological mechanics that take place the at the level of the plasma
00:42 . Alright. And so I just a bunch of big words in
00:44 like, physiology. And you're oh God, physiology. Alright.
00:48 really what we're gonna do is we're be asking the question if the if
00:52 if that membrane, the plasma membrane a barrier, how do things move
00:56 and forth across it. Alright. the reason we're going to ask these
01:00 , because remember what we've done is compartmentalized the materials inside the cell versus
01:06 the cell. And so we need be able to communicate between those two
01:11 . And so, what we're gonna is we're looking at these chemical laws
01:15 these chemical ideas that take place at level. So the idea here is
01:21 order to understand how the nervous system . You need to understand these basic
01:25 rules. If you need if you understand how muscles work, you need
01:29 understand this basic rule. If you to know how the kidney works,
01:32 need to understand these rules. Do see why we do this when I
01:36 I teach this class generally, and usually, what we're looking at here
01:39 kind of two lectures jammed together because the way the summer work. I
01:44 the classes when I teach this is , everything that you're gonna learn after
01:48 this week is based on or built everything we've talked about this week.
01:56 . And so learning this stuff makes the other stuff easier. All
02:01 And so the first part here, going to be kind of talking about
02:04 rules about how molecules move. And gonna kind of look at this in
02:09 in a way to make it easier understand, understand that there's some chemical
02:13 and some physical laws like physics type that we're not even gonna bother looking
02:17 . All. Right. So, of this stuff, you just kinda
02:19 to nod your head and go, , that's just how it works.
02:22 ? But what it's gonna do, gonna help us then understand how things
02:27 moving back and forth and how we take advantage of them. Alright?
02:30 gonna try to use some examples to it easy for us to understand.
02:33 so the first thing we're gonna do we're gonna look at this process called
02:36 and what we have here in this picture that we're looking at is we
02:39 have some sort of beaker with some in it. We've thrown a bunch
02:43 of molecules in in this case it be diet could be whatever you
02:46 You can think about iced tea and sugar into it or something. And
02:50 you imagine if you drop sugar into ice tea, you guys put sugar
02:53 your iced tea, right? You drink iced tea? Okay. No
02:58 , this is at least you said , this is the south. We
03:01 to learn how to drink our T I know it is sweet
03:04 but don't tell them yet. We'll to that in a minute. We'll
03:07 about sweet tea in a second. right. But you put sugar and
03:11 and it just goes right down to bottom right? And if you left
03:14 there and gave it an infinite amount time, those sugar molecules which are
03:19 kind of densely packed are gonna be . Now I don't like hanging out
03:23 these other molecules. I want to out and give me some elbow
03:26 And so that's really what the process diffusion is. It's basically these molecules
03:30 into each other and bumping into each with the same degree of frequency until
03:34 they spread out. And so that still bump into each other with the
03:38 degree of frequency, but they're they're spread out throughout the environment in which
03:42 in right now, this is a simple model of diffusion and there's some
03:48 that govern diffusion and we're gonna look the first two rules about the rate
03:51 diffusion. The rate of diffusion is upon the steepness of the gradient.
03:57 , what that means in english is you think about a skateboard and you
04:01 yourself on a skateboard and you and do this in Houston, are you
04:05 go anywhere? No, that's You said no, sir?
04:09 okay. Yeah. No. No. Do you go anywhere because
04:14 , it's flat in Houston. So you get on a skateboard, it's
04:17 going to move anywhere. But let's we move a little bit west,
04:22 moving in the hill country, we ourselves a little bit of a hill
04:25 I stand on that tape, or I going to start moving a little
04:29 ? All right. But if I myself to colorado, Now, I've
04:32 these steep slopes. If I get the skateboard, am I gonna be
04:36 ? Yes, And I'm gonna be fast or slow fast. In other
04:40 , the steeper the hill becomes the I go. And that's the simple
04:44 you already understand, and that's gonna the same principle that applies here,
04:48 steeper, the greater the more stuff have close together, the faster those
04:53 bump into each other and the faster disperse. All right, So,
04:56 rate of diffusion increases. Alright, # one. The second thing is
05:04 to do with temperature. All Now, we're getting to the sweet
05:09 . All right. If I dump in the tea, we said that
05:13 over time it might take an infinite of time, but eventually it's those
05:17 sugar going to spread around. But want our tea sweet right now because
05:23 hot. It's texas. So, do we do if it's unsweetened tea
05:28 we put sugar in it? What we do to it? How do
05:31 get that sugar mixed in? We it. And really what we're saying
05:35 how do we defuse the sugar? so what we do is we mix
05:39 by stirring. And really what we're is we're not just stirring. We're
05:44 applying kinetic energy, which is what is. The temperature is just applying
05:49 to the molecules so that they begin around. And so as you increase
05:56 , you'll get increased diffusion now to us a step down here in the
06:01 . And because it's hot all the , what we do is we take
06:04 tea while it's still hot and we throw the sugar into it and then
06:08 sugar because of the heat of the the fluid basically disperses. And that's
06:13 we get sweet tea and we just ourselves a step because this takes time
06:17 it's no fun. And we all sweet tea in the first place.
06:20 right. So, temperature has a effect on the rate of diffusion.
06:26 causes diffusion to occur much more All right. When you drop the
06:31 , you're removing kinetic energy and so move much more slowly, so things
06:36 much more slowly. All right, , this is just a simple
06:42 And you'll notice that what we have we have an open environment.
06:45 So, if you could think of body as being remember, we had
06:48 two areas intracellular fluid and extra cellular . If we put a whole bunch
06:53 stuff into the extra cellular fluid, gonna diffuse and equally distribute itself around
06:58 extra cellular fluid. But our bodies those two compartments And so we have
07:02 concern ourselves. Now with that barrier those two compartments. How do we
07:07 the stuff over in this compartment over that compartment? And here's where we're
07:11 start looking at a couple of different . Alright, Of course it helps
07:15 I actually press the button to allow to do that. There we
07:24 All right. So, with regard movement here, now, we can
07:28 this would be like where the extra fluid, this is intracellular fluid.
07:32 have this lipid bi layer and that bi layer we said serves as a
07:35 between the two compartments. What it is that it excludes things that sit
07:40 water, things that are water So just like me, I can't
07:45 through this wall. I need to some mechanism to allow me to pass
07:49 that wall. What would be the to allow me to pass through this
07:54 ? A door? And that's what have is we have different types of
07:58 . Now, the truth is, that some molecules are very, very
08:03 and or are lipid soluble, meaning they're able to pass through the lipid
08:08 layer. So when that occurs, happens is those materials are going to
08:13 the same rules we learned over where there's lots we move away from
08:18 to where we are equally distributed. you move from an area of high
08:22 to an area of low concentration so . So good. So, that's
08:27 rule that we first learned. We from areas of high concentration areas of
08:30 concentration. If that molecule is capable passing through that lipid bi layer,
08:38 uses the process of simple diffusion to so what that means is that that
08:43 , that membrane is permeable to that ? All right. But if that
08:48 is impermeable, that substance, that needs some other mechanism to get
08:52 And so that means it needs some . It needs to be facilitated.
08:57 we call the other mechanisms facilitated Alright. And there's a bunch of
09:03 types. One type of facilitated diffusion using a channel. Alright,
09:08 channel mediated diffusion is like a Alright. We have a door that
09:14 me to go back and forth. door happens to be closed, but
09:17 can open it. Right. And when you're dealing with channel media
09:21 you have an open path that allows to pass through it. When that
09:27 is open, it's completely open on sides. Just like if we open
09:30 those doors because we have two doors , if we open those doors,
09:33 anything wander in or out? dogs, raccoons, bees, other
09:40 . Right. So there's nothing that's barrier in a channel if it's
09:45 And the only thing that you're dependent now is a concentration gradient. If
09:49 have lots of stuff on this side very little stuff on that side,
09:53 move into the cell and I have of stuff on this side. And
09:57 little stuff on that side. Then move out of the cell. The
10:01 thing to understand here though is that doors are specific, they are specific
10:07 the type of molecules that they allow pass through them. All right.
10:12 other type is the carrier mediated if you want to think about carrying
10:16 different types of carrier media, but looking right here right now alright,
10:20 carrier mediated, this is just like door except that it's only open to
10:25 side at a time. The best I can think about is one of
10:28 rotating doors that you see at hotels at airports. You know what I'm
10:32 about? You got your suitcase and walk right up to it and you're
10:36 of like, okay, I've got get the timing right, and then
10:38 like get in and you're like and you jump out on the other
10:42 There's a point where if that stopped , you would neither be inside or
10:46 and that's kind of how this It's like you go in and then
10:50 it opens up your I mean, closed up on this side. Now
10:54 not exposed to either side and then open up to the other side
10:57 the same rules apply. I moved areas of high concentration to areas of
11:01 concentration. Alright now, both of mechanisms that you're looking at here are
11:06 to as passive diffusion. You're basically the mechanism to allow you move from
11:11 area of high concentration in the area low concentration and you just have to
11:14 which side has the higher the lower . Another type of career media diffusion
11:19 referred to as active transport. We're look at this a little bit more
11:23 probably in another slide. And the here is we're moving against our concentration
11:27 , We're moving from low to high because it's called active, it means
11:32 uses energy to do so, but go into more detail on the
11:35 So it's on the next slide. you go. So here I'm using
11:43 . I'm using a carrier when I'm with primary active transport. I'm using
11:49 directly. All right. In other , think of it like a bubble
11:52 machine. If I take a quarter stick the quarter in the bubble gum
11:55 and turn the crank, I get gum out the quarter is the energy
11:59 allow me to get my bubble gum . Alright, so that's kind of
12:03 the primary active transport works. I my molecule, it binds and says
12:08 ready to go. And then as as energy is there, then that's
12:11 be the thing that cranks the machinery allow you to move the thing
12:15 Now, the reason we need energy this case is because we're moving something
12:19 a direction that doesn't naturally want to . All right, think about this
12:24 I put um a bunch of ping balls into a closet and I opened
12:29 door, which way the ping pong are gonna want to go, or
12:32 gonna want to come out and roll , or they're gonna want to stay
12:34 the closet, they're gonna want to out, and So, what you
12:38 here is a mechanism that kind of a little part of the door to
12:41 something in. so it doesn't come out again. And what you're doing
12:44 you're moving things where it doesn't want go when you move things in that
12:50 , when you create that concentration and things in and creating more and more
12:55 more of that same substance. What doing is you're creating potential energy,
13:00 like lifting a ball and putting it a shelf. The ball wants to
13:04 to the ground, but you had impart energy to move the ball up
13:08 put it on the shelf, All you gotta do is bump the
13:11 or tilt the shelf just a little and the ball is gonna come rolling
13:14 the shelf, right? So primary transport is imparting energy and that energy
13:21 stored where you're putting that particle, I'm just gonna use again, here's
13:26 concentration gradient. So there's a little , there's lots, so, by
13:30 this in here and then over I've now put more particles where there's
13:34 lots of particles and the particles want go this direction. Secondary active transport
13:41 taking advantage of that gradient that you created. So the energy is expended
13:49 , but now it's stored over here so here in secondary active transport,
13:55 gonna use the stored energy to move else. Alright, so the example
14:01 , I mean, I don't know I'm actually doing, No, I'm
14:04 using a direct one. So an here would be I have moved one
14:11 over here. Now this particle wants go back because that's the directions concentration
14:16 . It's not allowed to go back it brings something else along with
14:21 All right. That's where the secondary transport. I'm using the energy that
14:24 stored up by pumping things over here that's gonna naturally want to go
14:29 but it's not allowed to go back it brings something. Now I'm gonna
14:34 a really bad example. You ready the really bad example? Alright.
14:38 I told you, where did I to school? Do you guys remember
14:40 I went to college, Chilean New Orleans? New Orleans is a
14:45 city, especially if you go to there. All right. And my
14:49 , we like to have fun in . You guys apparently don't like to
14:51 fun. We have fun. and In New Orleans there is a
14:56 about every three ft. All and around the campus especially there are
15:01 and tons of bars and every night was a ladies night at one of
15:05 bars. Now what they do is would charge a cover to get into
15:09 bar. Ladies could get in Um And guys wouldn't have to pay
15:14 cover if they weren't brought went in a girl. Right? And so
15:19 idea was is like all right, want to go in and I want
15:22 going drinking, I want to meet . Girls want to get in,
15:25 don't want to pay for drinks. now we've got some sort of symbiotic
15:29 going on here, right? All gotta do is hang out outside the
15:32 say hey, if you let me in with you, I'll buy you
15:35 drink. And who who benefits both us. Right. And that's kind
15:39 what? Secondary active transport is. active transport. I've got molecules sitting
15:44 here going, I want to get but I can't no one's letting me
15:47 . I don't want to pay the . And then we have a mechanism
15:50 allow us to move in. But we gotta do is bring another molecule
15:53 for the ride and say, if you come with me, I'll
15:57 you to where you need to And it's like, okay,
16:00 buy my drink and off you Terrible example, But can you visualize
16:07 ? Alright, we're gonna see some of this that you're in just a
16:12 , that you will not have to . But you're going to see that
16:15 are mechanisms all of these are mechanisms cells use to move molecules, particularly
16:22 back and forth across the membrane. , so with secondary active transport,
16:27 potential energy is being used to move against their own concentration gradient. All
16:34 now, these are the rules of . These are are summed up in
16:40 called fixed law of diffusion. you can go look up fixed law
16:44 you want to. In fact, you go on to uh Wikipedia and
16:48 up fixed law and see how he these. It's really kind of cool
16:51 he figured this stuff out in the 17 hundreds and he like created these
16:55 tubes, like as long as his and determined all these different things that
17:00 talking about here. But we're not go through the history. We just
17:03 to know what we need to All right. So, when we're
17:06 with the fusion across the membrane, , here's you can see I've got
17:09 concentration, there's low concentration. There's membrane. That's the part that allows
17:14 to pass through. There's some simple , size matters. All right.
17:18 bigger the salute, the harder it to move, the smaller the
17:22 the easier it is to move. way I think about this is um
17:26 have I don't have young kids but I used to have really,
17:29 young small kids and I take them have four of them, alright.
17:33 they're like gas molecules, they're always all sorts of different directions,
17:37 So, if I take them to sporting event, for example, um
17:41 kind of a big guy and when walking through a crowd, I bump
17:44 people, I have to say, me, and I have to kind
17:46 move sideways do this stuff. And of my kids do, they let
17:49 of my hands and they start zipping people's legs, right? And I
17:53 them in a crowd. So big hard to move when there's lots of
17:58 big things around, small things easy move around because they can zip between
18:03 . So the size of the salute when it comes to the radio
18:06 The smaller the salutes, the easier are to move. All right.
18:10 thing, membrane thickness. And this be pretty simple to understand if I
18:14 to move through something that's this you know, versus something that's that's
18:18 . It's gonna take less time to through it, right? So the
18:21 the thinner something is, the easier is to pass through It does that
18:24 of makes sense? Yeah. Okay, let me think about
18:28 Um Alright to get outside. we have this hallway, right?
18:33 , let's pretend the hallway is actually membrane, right? So, it
18:38 take longer to get from that door out to the other door to outside
18:42 it would if it was just a door, right? The thinner door
18:46 easier to pass through than the door the hallway in the door.
18:50 thickness matters, surface area matters. right. Um How many people do
18:56 think could fit through that these doors here? At the same time.
19:01 sounds good. I like four. . If we took one of those
19:04 away, how many could fit Two? Right, so the more
19:09 area we have, the easier it to pass people through that membrane.
19:14 , so more surface area, so just allowing more things to pass
19:18 You can think about the highway, you think about Highway 59 Highway 59
19:22 like six lanes over there in front Lakewood Church, right? So traffic
19:26 really, really easy. But if down closer to where 59 2 88
19:31 of separate, you have two lanes there's always traffic even in the middle
19:35 the night, there's people backed up there's just two lanes, the amount
19:39 traffic can't pass through because there's not surface area. This is again the
19:47 , so the steeper the gradient. the more stuff you got, the
19:50 it's going to move, the more the gradient, the slower it's going
19:54 move temperature. We mentioned as as you increase temperature that implies,
20:01 or applies kinetic energy so that things going to move faster. And
20:06 the viscosity of the solution. So what we do is we talk about
20:10 alright. And so typically that's what solutions are primarily water but a solution
20:14 water plus stuff. And so you have other things in that solution.
20:18 so we're not gonna worry about it much, but in some cases you
20:21 have to go, oh there's more just what I'm dealing with here.
20:24 so this will slow things down. it easier to pour out water than
20:28 is to pour out honey? so honey has a lot of stuff
20:32 it. And so you can imagine to diffuse through honey would be harder
20:35 diffusing through water. Alright, and this charge just kind of shows
20:40 it's like what what how it It increases or decreases it. So
20:47 kind of shows you really more like going on and you can look at
20:51 top here and the top refers to if we only had one salute?
20:55 right now, it is just simply one substance that that we're interested
21:00 So the term flux refers to the of diffusion. So if you ever
21:03 flux, that's just saying, how are these molecules moving? So you
21:07 see here, I've got lots of . This membrane right here allows for
21:11 particles to pass through it. So permissible to this particle. And so
21:15 rate of diffusion or the flux, just going to be dependent upon that
21:20 gradient. And they're gonna keep moving what we have is we have the
21:24 of movement in one direction equal to rate of movement in the other
21:28 Now you'd say wait a second, less over there. So wouldn't they
21:31 go that way until everything stops And the truth is, molecules don't
21:35 moving right, I can have a over here trying to move against its
21:40 gradient. It's really hard for it do so. But you know,
21:43 it's bouncing off stuff it can do . And so what you're dealing with
21:47 molecules hitting each other until the rate them hitting each other is equal on
21:51 sides of that membrane. So there's that are going this way, some
21:54 are going that way and that rate the same and that's what we refer
21:57 as being equilibrium. Alright, so here we are out of equilibrium
22:02 we're out of equilibrium here, we in equilibrium. The rate of diffusion
22:06 here is faster than the rate of over there. Right. Because the
22:10 have changed until finally the rate of diffusion is equal in both directions.
22:19 , our bodies don't have one We have lots and lots and lots
22:25 salutes. Even in our first couple lectures we talked about there being different
22:31 concentrations of ions in these compartments. mentioned potassium, we mentioned sodium,
22:36 mentioned chlorine, we mentioned these cellular proteins, which are the four
22:41 . But those aren't the only ones got magnesium, you have phosphates.
22:45 tons of stuff in our bodies and have to consider each of those things
22:50 we're looking at some of these reactions some of these activities. And so
22:54 kind of shows you what's really kind going on. So, if you
22:56 imagine this over here is extra This over here is intra cellular cellular
23:02 I have two different molecules. Each has its own flux. So the
23:07 of flux in this direction for red pretty fast. The rate of flux
23:10 blue is really fast in that Right? And so they're just moving
23:15 each other, independence of each All right. And so, you
23:20 see still the rate of diffusion for just gonna look at blue here here
23:25 really fast. But here it's gonna slower because we've got some on this
23:28 . And eventually what's gonna happen is gonna reach equilibrium for blue and you
23:33 reach equilibrium also for red. And , what you see now is you
23:38 different equilibrium. This would refer to net flux. Alright, So two
23:44 flux is going in different directions. , flux number one flux number
23:49 And then by here we're now into for each of those independent flux.
23:56 I want you to think about for moment about your breathing when we breathe
24:01 and breathe out. Let's talk about in. Well, let's breathing in
24:05 breathing out. What are you breathing ? What's that oxygen? Close close
24:15 , that's what I'm looking for. . Not a tricky question, no
24:19 . But you're you're thinking it's okay, I'm so used to them
24:21 me such a specific question. it's air you're breathing. But what
24:24 your body want? And your first was correct. Oxygen. Right?
24:29 we breathe in and breathing out, dealing with multiple Items will be dealing
24:34 multiple molecules. All right. But only concerned with one for our
24:39 But still, when I breathe I'm breathing in 79% nitrogen. I'm
24:44 breathing in 20% oxygen and I'm breathing something my body wants to get rid
24:49 carbon dioxide plus a whole bunch of stuff. My body doesn't want.
24:53 right. The movement of air is representation of a process called bulk
25:00 bulk floats simply refers to entire solutions areas of solution. It's a mixture
25:05 a bunch of gasses. And basically we're doing is we're moving from an
25:09 of high pressure to an area of pressure. All right. So,
25:13 I breathe in I'm pulling in all of things. I'm moving from high
25:17 to low pressure. When I'm breathing , I'm creating high pressure in my
25:21 and I'm pushing out air again. has my air concentrations changed in that
25:28 . Go ahead and your head and yes, because I turned oxygen into
25:33 dioxide and I'm breathing out a little more carbon dioxide than I was breathing
25:37 , Alright, But I'm still breathing oxygen, right? And so bulk
25:42 simply refers to that movement. Think your blood in your blood. You
25:48 water and blood cells and molecules and molecules and even more molecules that we're
25:54 going to bother naming. And for , one of those molecules is glucose
25:59 that glucose is trying to get to cell so that it can be used
26:02 fuel, right? It's not gonna like, oh well I'm just gonna
26:06 the glucose. I'm sending everything along it along with the waste that those
26:11 produce. And so that is also example of bulk flow. So molecules
26:18 by rules that we've just described diffusion whatnot. But that's looking at an
26:24 molecule they also follow or rules that the whole solution itself. So when
26:32 breathing in we're breathing in a whole of things. Moving things again with
26:37 concentration gradient. But then when we're oxygen we're following the rules for that
26:42 molecule. We're moving carbon dioxide. following its own rules as well.
26:47 we gotta understand there's some complexities and molecules move. Alright now the good
26:52 is we're not going to deal with until A and P. Two.
26:55 understanding this concept is going to help understand respiration. The cardiovascular system and
27:01 renal system when they come up, , That's the fun part in the
27:08 . You get to use this in future. You'll get to use this
27:11 far. We're okay with stuff. three nods. And the people in
27:16 back falling asleep. I really, want to bring a silly string Class
27:23 Day. Just see if you guys up. Alright. So what we
27:29 have is we have a term that use when we talk about a
27:33 You've already heard me use this term this morning and it refers to
27:38 Alright. So what we do is say that membrane is permeable when it
27:43 a substance to pass through it. for example, our plasma membrane is
27:49 to oxygen. It's permissible to carbon . Alright, so that means there's
27:54 barrier here for those molecules. It even see the barrier just passes on
28:00 . So materials are going to move an area of high concentration to an
28:03 of low concentration, simply by following rules of diffusion or simple diffusion.
28:09 . We have other molecules like ethanol, water which are polar molecules
28:15 they shouldn't be present, prevented or shouldn't be allowed to pass through but
28:19 still permeable membranes still permissible to them some other sorts of chemical reasons we're
28:25 going to go into. If a is not allowed to pass through like
28:31 , glucose is too big and it's , it will not be able to
28:35 through. It just sits out here the water. It needs a mechanism
28:37 allow it through. So what we is that the membrane is impermeable.
28:41 the glucose or membranes are impermeable to . So, there has to be
28:47 sort of mechanism to allow them to through one of those uh facilitated transport
28:52 that we looked at. And then we look at a membrane itself,
28:55 we do is we say, it allows some things to pass through
28:59 other things it doesn't. So, means it has selectivity. It determines
29:03 gets to decide when things are going go through it. All right.
29:08 , a membrane is permeable to some like oxygen, carbon dioxide, but
29:12 impermeable to others. And then there's be times when we put channels through
29:16 allows for membranes or these materials to through. So, all the membranes
29:21 all ourselves cells are collectively selective. . They're selectively permeable. But when
29:27 looking at a substance, we can that membrane is permeable to blank.
29:33 that number collection kind of makes Alright. Alright. The dread
29:40 How many guys have learned about osmosis ? All right. If we didn't
29:44 about it. How many think you explain to somebody else clearly. So
29:47 they understood it and that you could a perfect score on the test on
29:53 . Yeah. See that's I don't . All right. Osmosis is one
29:58 those terms that everyone screws up. . I remember sitting in your seats
30:04 first time and not understanding. And I'm going to just memorize what they
30:07 me and I'm gonna vomit it back the exam. And I remember being
30:10 grad school going okay. I vaguely what osmosis is and I'm just gonna
30:13 like I know and stuff like It wasn't until I started teaching when
30:17 was like, oh this is the thing as why do people keep explaining
30:20 so poorly to me? All you ready for the easy explanation?
30:25 the chemist explanation. Because those are people that screw us up because what
30:28 chemist will tell you is like osmosis the movement of water to an area
30:32 higher concentration of solute. And all a sudden now you're like what
30:37 Because we've already learned a really, simple definition. We said what is
30:42 , diffusion is things moving from high , low concentration. But if I
30:45 osmosis is water moving to an area higher solute concentration all of a sudden
30:49 makes a lot of not sense. ? You said I'd use bad language
30:55 , right? The idea here is changing what you're focusing on.
31:02 and osmosis is simply water diffusion. you learn that it's water diffusion,
31:10 it just makes sense. Okay, there are physical rules that govern
31:14 There are chemical rules that govern And I'm gonna try to see if
31:17 makes sense to you by drawing this . Give you guys a little bit
31:22 light. Not at all help. right here I have a container with
31:32 membrane. Alright, if I put say 70% water here, and
31:41 I don't know 30% water there. way do you think the water?
31:45 this membrane is permeable to water? way is the water gonna go?
31:49 going to go to the right? very, very simple. Alright,
31:52 notice I have 70% water here when talk about the fusion, we talk
31:56 salute in water. And now what talking about, how does the water
32:00 If it's 70% water? What's 30% of Who knows saw you?
32:07 , It's just we don't care what is. It's something that means this
32:12 70% of something. We don't know it is. But instead of focusing
32:18 this, just focus on this part there. Just focus on the
32:23 Because the question is asking when you're with osmosis, if you have a
32:27 permeable to water, which direction does water go? It moves to where
32:32 less water. That's pretty simple. rolls downhill. Something you've already
32:39 All right now the chemists get confusing they sit here and start focusing on
32:45 , you have a high water concentration here and you have a high solute
32:49 over there, Which way does the go? And all of a sudden
32:53 you have to do brain translation of that means. And really wherever you
32:57 high. So you just think that low water. Okay, And that's
33:02 the language of osmosis comes in. start dealing with that that conversion.
33:08 so you have to kind of do small translation in your brain to always
33:12 I've got to come back to the . All right. So osmosis is
33:17 movement of water through a selectively permeable selective to water. Alright, so
33:25 you can see this light purples. we decided was lilac. Yeah.
33:33 right. It's too early for It's blue. Okay. I
33:40 we can we can sit here for . I know it's like I don't
33:44 . All right, but that's supposed represent your water. If you look
33:48 the red dots represent your salutes. ? So, you already know by
33:52 looking at this. I can see a lot more water over here then
33:55 over there. So what do I to do is I need to move
33:58 in that direction. Now, if membrane was permissible to both the salute
34:04 the water, the water would move way, the salute would move the
34:06 direction. And you'd see equilibrium in cases. But this particular membrane is
34:14 to that salute. So water is to move to where there is less
34:18 so that it can reach equilibrium for . And that's why you get these
34:21 pictures right? Which is what your says. That doesn't make sense to
34:26 because it shouldn't climb that direction. , the way that water moves is
34:31 it can move through a membrane like plasma membrane. It's it's permissible to
34:35 membrane but it also has in that channels which we call aqua por ins
34:42 a fancy word water pours. So can move through the channels or it
34:49 go in between the fossil lipids because itsy bitsy and it breaks all the
34:53 that you try to learn as you're to learn about plaza membranes.
34:58 So that's what I was. Most . It's simply moving water down its
35:03 gradient. Now, the example I to use and we're gonna use hydrostatic
35:09 . We're gonna get to these two things. Alright. Hydrostatic pressure is
35:12 the pressure that a fluid exerts on things that are are pressed up against
35:19 . So we have water bottle, bottle, we have a Starbucks.
35:23 can see that there's fluid inside those where if you were to punch a
35:27 in the side of your little what would happen to the fluid inside
35:32 would try to go out. And because there's hydrostatic pressure, gravity has
35:35 effect on that. The water has itself and it's trying to escape so
35:39 it can be one molecule. Alright here, One molecule thick on the
35:43 , right? It's just trying to out as thin as it can
35:46 All right. But the force of containers are strong enough to overcome the
35:52 inside. But you can imagine if applied more and more fluid inside that
35:56 could get the bottle to burst. ? That would be the hydrostatic
36:00 So when you hear hydrostatic pressure, water. So hydrostatic pressure is simply
36:05 pressure inside of a fluid trying to that fluid to escape whatever containers it's
36:13 osmotic pressure is the opposing pressure. its a hydrostatic pressure, right?
36:19 a pressure that's outside that tries to osmosis. Alright, you guys know
36:25 a smart car is. Alright, many people can you fit in a
36:29 car? You're not trying. I ask. How many comfortably can you
36:35 in a smart car? How many ? How many people can you fit
36:38 a smart car? Let's say you one that's about right now.
36:44 so your college students, you got to go. You're all going out
36:50 right? Because no one studies at anymore. All right. And you
36:53 a smart card. You got eight that you want to go. So
36:55 take two people you put them in want to drive and you just start
36:58 people in there like cordwood. You're going one die and you're just
37:02 to push them in around person. six, you're gonna start feeling the
37:07 of that space is a little bit . And now the pressure inside is
37:10 much higher than it was when you one or two people in it.
37:15 you get person number seven, you pushing them in and that pressure is
37:19 to oppose that person coming in At # eight, you're gonna get that
37:24 pushed in and someone's gonna pop out other side, right? Because there's
37:31 so much space inside, that's like pressure. Every time a molecule moves
37:38 this side to that side, you've the hydrostatic pressure in this space,
37:43 ? That means the pressure over here drive a molecule in this direction has
37:47 be greater than the pressure on this . Every time I add another
37:51 you know, we're gonna keep but I'm increasing the pressure here and
37:55 , what's gonna happen, Let's say done it over time, eventually there's
37:58 be a molecule that goes in. then the pressure here says,
38:01 don't want you and it's gonna kick molecule out the other direction. And
38:05 the movement of water in this direction equal to the movement of water in
38:09 direction. Right, we reach a of equilibrium. Now you look at
38:14 again, your brain is looking at going, wait a second, this
38:16 taller than that one. Don't look that. Think in terms of number
38:20 molecules that you can't see here. ? And so the hydrostatic pressure that
38:26 the flow, or the movement of down that concentration gradient when that pressure
38:33 so high that it proposes it. found the osmotic pressure. Does that
38:39 of makes sense? I got one nodding the rest of your staring at
38:43 like I'm crazy. This is why like using that smart card example.
38:52 . Oh, can we osmosis the content is getting equal to? I
39:02 not. Alright, So the question , can we say that with osmotic
39:06 ? That's the water is getting the as the solute. It's not the
39:11 . It's it's literally you may not Water equilibrium. So here's 72,
39:17 ? You may not be able to that. Where what would be the
39:21 between 70 and 30 would be Right? It may be that the
39:25 on this side Only allows you to to 40% water on that side.
39:30 . So the pressure is what becomes at this point. All right.
39:34 not about the equilibrium of the number molecules. It's the pressure. All
39:40 . Yeah, that's a fair question again, your brain wants to
39:43 I like I like things nice and and equal and I want things to
39:47 pretty. I mean, right, it's not going to be that.
39:52 all you have to do is just about osmotic pressure is simply the resistant
39:58 that prevents water from moving into that . It's a hydrostatic pressure. So
40:10 probably asking, who cares? Why I need to know this stuff?
40:13 I'm now talking to the nurses the nurses in the room. All
40:18 patient comes and sees you or You particularly, you're just assigned to
40:23 , Right? And they're dehydrated and know, okay, well if this
40:28 is dehydrated, I need to give water, right? Because that's what
40:35 been taught. But we've already learned diffusion and we basically don't understand and
40:40 not gonna explain some principles of physiology you become dehydrated, the environment inside
40:45 cells try to match the environment outside cells. All right. So if
40:50 just understand that, just kind of your head like, okay,
40:53 If I give somebody pure water then I've done is now I've created an
40:58 gradient that favors water rushing into the so that the cells expand very very
41:05 and then what happens pop Because you've this at some point. Right?
41:11 way back in like 8th grade, learned about the blood cells. You
41:14 blood and water and they pop and you put salt, they shrink and
41:19 like that. Did you guys learn ? That's tennis city? And you
41:23 these terms hyper tonic isotonic and HIPPA . And again it's just prefix and
41:29 . That portion refers to the presence solute. Thank you again for screwing
41:34 up and make me learn one more . Right, tonic instead of dealing
41:37 the water. So when I look a solution, I'm asking,
41:40 it's water plus stuff. If I a hyper tonic solution, that means
41:44 stuff in the water is more than normally is. If I have an
41:49 solution, the stuff in the water what it should normally be. And
41:55 a hip a tonic solution is where stuff in the water is a lot
41:58 than it should be. Alright. used to just thinking in terms of
42:02 water back and forth, cause that's easy thing to do here. But
42:06 body, you know, if you your body, it has a certain
42:11 to it. And so what we'd is the number of salutes in your
42:15 is a specific value. So if take a solution that's isotonic, what
42:20 doing is we're not adding an extra or extra water in terms of
42:26 What we're doing is we're just adding more stuff and so we're increasing the
42:29 in your body. If I want move and oppose dehydration. For
42:36 what I wanna do is I want add in something that's not isotonic because
42:40 doesn't make you dehydrate less dehydrated. I wanna do is I want to
42:43 something that has more water but I want it to be just pure water
42:48 if I push in pure water water gonna rush into the cells and cause
42:53 to bust. So I'm going to something that's hip a tonic. In
42:58 words there's gonna be salute. But I'm doing is I'm slowing down.
43:01 other words, I don't have this slope. I'm making the slope a
43:06 less. All right. So if in nursing, you're not going to
43:12 about osmolarity. You're gonna be talking tennis. Itty. Alright. So
43:18 terms become important. Hyper tonic hyper tonic salute has more stuff. If
43:25 have more stuff that means you have water. All right. And it's
43:31 to a solution. So when you that solution in that means you have
43:37 penetrating salutes. Alright, that's hypersonic here's hyper higher penetrating salutes and less
43:48 isotonic. Anyone here ever used Visine is stuff your eyes when your eyes
43:55 all red and itchy. Yeah. , It's an isotonic solution. It's
44:00 saline solution or 0.9% saline solution. me when I dripped that stuff in
44:07 eyes, it has the same salutes terms of conservation. Not the same
44:12 salutes. The same concentration of salutes my tears have. And so it
44:18 in and goes refreshing. All Doesn't suck the water out of my
44:24 and it doesn't make water just drip over my face. That's isotonic same
44:31 equal non penetrating salutes or equal And lastly is the hip a tonic
44:38 low salutes high water. So when look at those words, think salute
44:45 then you have to do the conversion your brain for the water park.
44:58 we mentioned facilitated diffusion already. And I know I don't pause.
45:04 sir. Go ahead. This is you make me pause. Yeah.
45:07 gonna have to speak up really loud you. Mhm. I can sorry
45:23 speaking loudly. But the problem is there's a lot of space between you
45:26 there's lots of noise so with the it actually reflects back at you.
45:29 go ahead. Try one more Uh huh. If cells perform many
45:38 . So you got to think of like this in terms of why we
45:42 so many different cells is because each cell can only do a very very
45:47 part of the job if you want build. I'm just gonna use something
45:51 stupid example. If you want to a tower right? With legos,
45:56 could use to legos to do And then in your brain you'd say
45:59 a tower. But I would look and say that's just two bricks stuck
46:03 . If I want a tower I to use lots and lots of because
46:06 representation of a single brick doesn't really you that that full functionality of say
46:14 that what that brick brick represents. a terrible example. See this is
46:18 it's terrible for me to come up stuff on the fly. So let
46:23 be clear in terms of what you're . Are you asking why do we
46:25 so many cells in our body or there's so many different types of
46:37 Right. Yes. So why? ? Your question is why do if
46:42 have so many different functions? Why I have so many of the same
46:46 of sales doing the same thing? the amount of work that needs to
46:50 done, for example, can be by a single cell small cells.
46:55 , you're you're you're asking me to through a lot of things here regarding
46:58 here. Cell theory cells are very functional. The smaller they
47:03 And as they grow bigger in they become less and less efficient in
47:06 type of work that they do. that's why it becomes important to divide
47:10 . So, that's why you don't a lot of very large single cell
47:13 because at a certain point, they less efficient as they grow in
47:18 Alright. And you probably realize this the things that you do organizations become
47:23 efficient as they become bigger and bigger bigger. Right? It's a natural
47:27 . It actually occurs not just in , but in a whole bunch of
47:31 by a bunch of other areas. right. The second thing is in
47:36 of the actual things that they So if you look at, for
47:39 , a small, a small that's just a couple of different
47:43 It does it can do a couple things. But each of the sum
47:46 the parts of that that they do to grow in order to accommodate all
47:50 specialties that each of the individual cells . So for example, if you
47:54 a cell, I'm just making up that's responsible for producing glucose, it
47:59 to make enough glucose for all the to be functional. And then that
48:03 the things that it doesn't do, cells have to take over that
48:07 And so you're gonna have to as increase the number of things that are
48:10 different things. That means you have get more and more of those cells
48:13 do that type of job. So say now you have that one cell
48:19 make enough glucose for five cells. have to get a second cell to
48:22 enough glucose for the five cells. now you have to have another group
48:25 cells that make enough for to accommodate those cells that are making the
48:31 That kind of makes sense. Like increasing the workers to better
48:40 And so again, you can apply , you can kind of look at
48:43 how, you know, like a works or how um, you
48:47 organization works. It's like, you , I go and get a helper
48:51 help me do the job. They doing the job. And now it
48:54 me up to do something else. now there's not enough people to do
48:57 job that's going on over here. , I gotta hire somebody else.
49:00 so you can start seeing where the multiplication effect is. You become more
49:06 and better at doing something and you actually increase the efficiency of the one
49:09 . But you have to have more more support for those other cells that
49:13 doing that. That kind of answer question. All right. And that's
49:19 to get me off topic too. all right. I'll talk about anything
49:24 about forever. And I know you are dying to get out of
49:28 I do have an end point here I want to get to you before
49:30 stop. Alright. So, we about facilitated fusion and really what we're
49:36 about when we're doing that is we're about proteins that are found in the
49:40 membrane. Remember we said the plasma is lipids and proteins. And
49:43 the proteins, some of the proteins the membrane are transport proteins. They
49:48 molecules to pass back and forth. right. These transport proteins have both
49:54 open and closed figuration, just like doorway does. So, right
49:57 those doorways in a closed configuration. can't go through the door unless you
50:02 it. Thank you. All So, that's kind of how channel
50:07 work. Alright. It's going to how much you can transport. And
50:11 you're gonna do is with regard to channel protein when you open that door
50:14 gate. That's gonna allow for salutes move across that membrane down. Its
50:21 gradient carriers are a little bit As we said, they imply that
50:26 is something being moved directly or bound that protein. And so they're open
50:33 to one side. So, when bind it, that causes a change
50:36 the shape of the molecule so that switches over. Right? There's a
50:40 immediate uh an intermediate state where neither is open and then it opens up
50:44 the side and it releases that material on the other side. And then
50:48 we're using energy, we're moving things the concentration gradient. When we're not
50:52 energy, you're moving with the concentration . Now focusing on the channels for
50:58 moment, what we're looking at here that there are different types of channels
51:03 can be opened by different types of lack of a better term. Right
51:08 , they're called gated channels and I know why they said gated channels versus
51:13 doors or whatever. I mean, just language but you can think of
51:17 in terms of a door. So we have some doors that require
51:22 . Like a physical key. We other doors that can have like a
51:26 , right? We have other doors have that little like at the bathroom
51:30 you wash your hands and you don't to touch horrible things, you've got
51:33 little foot thing that you can pull door open with. You have doors
51:36 handles. You got different types of have different ways of opening them.
51:40 all agree with you on that. . And so that's kind of what
51:42 channels are. Is there are different of opening different types of channels.
51:47 it's only this one mechanism. We to these mechanisms as modalities.
51:51 So, for example, the easy to think about is ligand gated ligand
51:56 a molecule that binds another molecule. ? So, if you say ligand
52:00 channel, it's a molecule that binds channel and serves as a physical key
52:04 open the channel. That's an easy . And so when we can all
52:09 but we have some other ones. , for example, you can have
52:12 thermally gated channel which is not shown here when the temperature changes, that
52:16 the molecule change shape, which causes gate to open a mechanically gated
52:21 There's manipulations of the plasma membrane. the plasma membrane gets manipulated, causes
52:26 channel to be manipulated, it causes to open up another one. And
52:31 is what we're going to spend quite bit of time with is the voltage
52:34 channel. Alright. And we spend lot of time with it because that's
52:37 nervous system and muscles voltage gated channels charges associated with them. And so
52:43 the charges around that channel change, causes that channel to open or
52:51 All right. So that's the voltage channel. And so the term we
52:54 when when the the charges change. called the membrane potential. And we're
52:59 get to that a little bit So, when you see that word
53:01 freak out, it's just potential refers potential energy which refers to the presence
53:05 ions. So there's these different types channels that have different types of mechanisms
53:11 open and close them. And when open and close the channel, you
53:15 or decrease the permeability of the So, if I have a closed
53:20 , that membrane is impermeable to whatever substance is that that channel allows to
53:25 through. But when I open it your membrane is permeable to.
53:27 Does that kind of makes sense? . Primary active transport is that type
53:34 carrier where we're moving to things against soil. You're using energy.
53:42 In this case, what we're gonna . We're using the example of the
53:46 common type of pump that we find the body, which is the type
53:50 primary active transport, the sodium 80 pes pump. sodium potassium are
53:56 moved. And it's using energy as pump to drive this this thing.
54:02 a real simple mechanism. And what gonna do is it's gonna change.
54:06 how he said the extra and intracellular are different. It's this pump that's
54:10 for it. You see what happens you can imagine imagine an environment where
54:14 the exercise and the intracellular fluids are same. And I have this
54:19 I have this pump. What I'm do is I'm gonna pump sodium out
54:23 the cell and I'm gonna exchange it potassium from the outside of the
54:27 So what I'm doing is I'm pumping into the cell, pumping sodium outside
54:32 cell. I'm doing this at the of 180 p. And that's kind
54:36 what's going on here saying, look , this is the inside of the
54:39 . I'm taking sodium naturally wants to to it. It doesn't want to
54:43 out of the cell. It just to bind to this. And when
54:45 binds, that creates an attraction for T. P. To bind to
54:50 . When the ATP binds and these molecules bind, it releases the energy
54:54 changes the shape of the carrier when get to the other side, you
54:59 longer have binding sites. Alright, binding sites basically no longer like binding
55:04 to sodium. And so they do you gotta go out and it's like
55:07 right, well, I have no . And then it just follows the
55:10 of diffusion. Just kind of moves from where it was bound up.
55:13 , there's more sodium out here And so it doesn't want to go
55:16 direction, but it has no Right? It's like that's the way
55:19 gotta go. Just go And so what it does at the same
55:24 What you do is you create potassium sites, potassium look binding sites and
55:28 goes and binds to it. And when the to bind the two potassium
55:33 , the sodium are gone, then changes shape and goes back to the
55:36 original shape and then to potassium are and so, what you've done now
55:42 you've moved ions against the gradient and created to environments where you now have
55:49 of sodium, sodium wants to come in the cell, but there's no
55:52 for it to do. So, got lots of potassium inside the cell
55:55 it wants to go out, but has no mechanism to do.
55:58 you now have stored up potential energy it's this potential energy that this mechanism
56:03 us to have or that that that this mechanism creates that we can then
56:10 to do some really, really cool in cells. All right.
56:15 it basically is acting like a The cell acts like a battery in
56:18 way by storing up energy. pumps don't just exist exist like
56:24 I mean, this is the primary , but there's lots of them we
56:28 like proton pumps. And so here , you're going to use a
56:31 P. Right? I have lots protons down here and I don't want
56:36 here, I want them out Right, you can think of this
56:38 like the license zone. This is inside of the cell over here,
56:41 inside the life zone. So what wanna do, I wanna put a
56:44 of protons inside the license zone. what I'll do is just keep pumping
56:48 a TP to pump protons into the zone. And I created a little
56:53 vesicles full of protons, very very . So pumps are a common mechanism
56:59 move molecules against their gradients at the of energy. Here's that example of
57:07 active transport. Alright, so over this side is my sodium 80 pes
57:15 . Alright, so what do we ? We pump sodium out there,
57:18 put potassium in here, we're doing at the cost of 1 80
57:23 So I've got lots of sodium in and it wants to come back inside
57:25 cell but it didn't have a mechanism do so so it's hanging outside the
57:29 going, how do I get back the bar? And then glucose comes
57:33 saying you know what I really want go in there but I can't there's
57:36 much glucose. So um hey why we make a deal? I'll go
57:43 and I'll bring you along and then way we can both go in
57:47 you can go where you want to and I can go where I want
57:50 go. But even though I'm not and you're not allowed, this mechanism
57:54 me. So sodium binds glucose binds both of them bind. We use
58:00 energy that that power to move glucose the cell. Alright, you're
58:05 So what? Yeah, that's the of unit porter. Yeah. And
58:11 gonna look at it on the next slides. The two slides of
58:14 We don't need to memorize. All . What? This is showing you
58:20 is how we move things without actually energy. Alright. Energy is something
58:27 we cherish as a cell, so don't want to waste it. And
58:31 represents energy stored, right? I if I break down glucose do I
58:36 energy out of it? The answer yes. Right? Remember if I
58:39 just glide colleges, I get 4 P. And then if I go
58:42 the whole process through all the different , I get 34 to 38 80
58:47 . So, I don't want to energy to move energy. You
58:51 That's that's wasteful. Right? this is a mechanism for me to
58:57 energy without having to spend it. ? I moved three and sodium is
59:04 there at the cost of 1 80 . And I can move a whole
59:08 of things. This isn't the only of sim porter that exists,
59:13 This isn't the only type of secondary transport. If things move in the
59:17 direction, That's a sim porter when move in the opposite direction. So
59:22 is going out, potassium is going . That's anti porter. It doesn't
59:26 if it's active or or secondary Just describes the direction molecules are
59:33 Now, I'm just gonna show you slides and then you guys can go
59:36 a break real quick. All And I show you these slides.
59:41 do not memorize these things. But I want to show this to
59:45 because if you understand the generic right? I understand what primary
59:53 I understand it was secondary active. understand what a sim porter is or
59:57 anti porter or unit ports or multi , what those are descriptive. And
60:03 body uses these types of mechanisms over over and over again for very specific
60:12 in very specific or unique ways. ? So, the artist here is
60:17 to show you, you know, what a pump looks like,
60:19 So here's your sodium potassium pump. look, we have calcium hydrogen
60:25 We have a calcium pump here. , this is called circa You don't
60:29 to know that. Right? And we have is we have these multiple
60:35 that are conserved. There's that hydrogen . And so once you learn how
60:39 pump works. Once you know how works every time you see it.
60:43 kinda makes sense. Similarly, I the wrong direction. Similar. Here's
60:48 channel. Look at all these There's your potassium channel, there's a
60:51 channel voltage gated channel, there's a gated calcium channel. Over on this
60:55 channel channel, here's a channel, a channel everywhere. The channel
60:59 Right? Once you learn how to works, you always know how it
61:03 . Now. You're just looking at . Oh this is the calcium
61:06 Oh this is the potassium channel. just to let you know there are
61:11 plus sodium channels in the body. , goody, good news. You
61:17 have to know. Right then you like transporters. Right? So here
61:23 have sodium moving saying amino acid sodium glucose. So they're calling it a
61:28 . Co transporter. So, if understood this, you already understand co
61:36 . Alright. I have one thing wants to go in. One
61:39 The other thing wants to go and moving with its concentration, ones moving
61:42 its concentration and so that's how we those across. And so we'll see
61:47 over and over again. There's one an anti support system but it's called
61:51 exchanger. It's a co transport Anti report. All right, Look
61:58 this one is a fun one. called N. K C.
62:02 But again, not having to know you can look at and say,
62:05 look, I'm moving a sodium and into chlorine and it's using the exact
62:09 mechanisms. It's moving one thing against gradient and a couple of things with
62:15 gradient it's able to do that because understand or you're able to understand because
62:21 that. Here's an exchanger, other . All sorts of different. Here's
62:26 co transporter, both things being pumped . And this is the stuff that
62:33 going to see over and over again the body and allows the cells to
62:36 the unique things that they do. we're gonna stop here for a
62:43 I spent a lot of time talking stuff like that Saturate for a
62:47 Why don't you guys go to the , get back here by 10,
62:51 and let's see what we can finish . Mm. Alright, So what
63:02 gonna do is we're gonna just continue with this movement of materials. Some
63:08 in the body are too big for are too big for carriers.
63:13 when we're talking about carriers and we're really talking about very very small
63:16 . All right. But if you're about, for example, hormone or
63:21 sort of cida kind if you've never the word side of kind of type
63:25 signaling molecule, big things can't be back and forth through channels. You
63:30 something bigger to do that. And where these vesicles come in. So
63:34 you think about the inner membrane remember we talked about that we went
63:37 nucleus to E r er to golgi to um vesicles vesicles to to something
63:45 we refer to the plasma membrane vesicles one of the ways that we move
63:50 out of the cell. It's also way that we bring things into
63:54 And so when we talk about vesicular there's some terminology that we use.
63:58 when we are secreted something or removing we call that exocet. Oh sis
64:04 right. And so this will be example. Here's our vest ical you
64:07 see we've got some sort of particles it that we want to secrete from
64:10 cell. And so it merges with plasma membrane through those snares that we
64:14 about. And then what you're gonna is you're going to release that material
64:19 you get that material merged or that membrane and that vesicles merge together.
64:24 right now this does require energy. anyone watch the little video with the
64:29 the um the google Yeah. For . The google video. Youtube.
64:36 . Um And you saw like they you exocet, oh sis they showed
64:41 the transport of vesicles. Um And can imagine each and every one of
64:47 things, those movements of steps that with the membrane. Each cost
64:51 And that's when we say a teepee energy is required for this endo psychosis
64:58 just the reverse. And of course no picture for me to show
65:01 But the idea here is that you're to have some that's still exocet Oh
65:06 sorry, come on. There we . There's an acidosis acidosis is just
65:13 opposite. The idea is that you the membrane and there's something that allows
65:18 to either bind to or selectively collect even non selectively collect materials from the
65:25 cellular fluid. Now there's lots of types of endo psychosis. And depending
65:29 which type of book you look they have define things differently. And
65:33 what I've tried to do here is these broad categories or use these broad
65:37 . The first one is Figo psychosis we we kind of looked at that
65:40 we're looking at the license zone because picture showed a macrophage. And what's
65:44 about Figo psychosis is that psychosis requires plasma membrane to be extended away from
65:51 cell and is around the thing that actually trying to consume, right and
65:55 I'm using that language of eating Because so what you're doing is you're
66:00 you're like, oh here's the I'm like okay, here it
66:02 And what I'm gonna do is I it and then I extend my plasma
66:07 and it wraps around it and it the thing I'm trying to eat inside
66:12 vesicles and then that vehicle can be with the license. So typically this
66:17 gonna be very large material, you , relative to the cells. So
66:21 can be parts of cells. I like lots of pieces in the whole
66:25 , that sort of thing very early they recognized and I say they being
66:31 recognize another mechanism of indiscriminate absorption and what it is. Is that the
66:37 membrane in dense itself. So instead reaching out what it does is it
66:41 or imagine eights and then closes in creates a vesicles kind of like this
66:46 kind of pulls down and then and whatever happened to be trapped in there
66:50 now going to be used by the and that's kind of it's indiscriminate.
66:54 nothing that it's looking for specifically. just kind of grabbing in whatever is
66:58 the exercise of fluid trapping it and using whatever whatever it captured. So
67:04 had cell eating. So we're just call that one cell drinking. That's
67:07 the name came from pinot psychosis. right. But there's another kind of
67:13 there's actually a couple more which we're going to go into. But another
67:17 words now, it's more specific and what you have is in your uh
67:22 your member you're gonna have a series receptors right? They're gonna be sitting
67:25 on the surface and when they get they're being bound by something specific.
67:30 that receptor recognizes only one kind of . And when you bind those those
67:35 those receptors congregate to a region that protein associated with it's usually called a
67:42 coated pit and I don't know if I don't have it labeled there so
67:45 molecule is clattering and so when enough these receptors that have been bound by
67:50 remember we said what ligand is it's non specific term meaning a molecule that
67:55 another one. So when you have ligand bound up to receptor and they've
68:00 with these clattering in this specific area the whole thing pinches off and you've
68:06 captured up whatever it was specifically that looking for. Alright so whenever you
68:11 receptor think specific I'm looking for something and what's interesting is once it pinches
68:19 then what you can do is you actually recycle the receptors, send them
68:22 up through the process of exito sis out the things that you bound up
68:26 then you know do whatever it is you're going to do to it.
68:31 what we have here is we have couple of different mechanisms in which ways
68:34 ways in which materials are moved inside outside the cell. You can kind
68:39 see how this kind of went with last stuff but we kind of just
68:42 of set it off to the side we have diffusion right? We have
68:47 of transport through channels and carriers and carriers can be pumps right we can
68:53 things with their concentration gradient or against concentration gradient depending on the availability of
69:00 and then we can move big things well as small things. And so
69:04 these different types of mechanisms that allow cells to move things back and forth
69:09 and out of the cell. Now really easy to think about cells just
69:14 of sitting around and doing nothing and working independently and just kind of doing
69:17 thing. But the truth is the are very very talkative, They are
69:23 upon each other to know when and to do things. And so what
69:27 have is we have this process called signaling. It's just a field of
69:33 describes or term that describes how cells to each other. Now there's how
69:40 talk and to whom they talk depends the cells and where they're located and
69:45 their targets are. But so what can say is look they're gonna be
69:48 if they're close to each other, fast do I need to do
69:51 Where's my target cell gonna be? all have big influences on how and
69:57 or how what mechanism gonna use to Now the most common form of
70:04 His chemical communication. Right? So I can do is I release a
70:09 through the process of excise exocet. sis and then you pick it up
70:13 receptor and that tells you what to . Alright. So this is by
70:18 the most common but some cells that connected to each other can use electrical
70:25 . In other words, they can ions. So when I move ions
70:29 and forth across the membrane, I'm the charge across that membrane which is
70:35 electrical change. And I can use movement of ions as a signaling mechanism
70:41 myself. But I can also use signaling mechanism to cells that I'm connected
70:47 . Alright, so chemicals the most electrical is the next most common or
70:54 other type I should say. And going to focus in primarily on the
70:58 and when we get into the nervous , we're gonna talk a lot about
71:01 electrical mechanism. All right. So that in mind let's take a look
71:08 at the different types of chemical When you go grocery shopping. Do
71:12 write yourself notes? Do you make a list? Okay. Not all
71:16 time, but sometimes. Right. . That's what autocrats signaling is.
71:20 basically talking to yourself. If you you study when you study, do
71:24 talk to yourself? You know, had a friend in high school,
71:29 talked to herself and she didn't know . I mean she would just talk
71:32 you're like yeah, so what she I mean verbal talk to herself,
71:38 kind of what autocad and signaling Right, basically what you do is
71:40 secrete uh some sort of chemical message it's capable of binding receptors on your
71:45 cell. And you'd say well why I ever need to do that?
71:50 , remember negative feedback mechanisms you may turning off a system that you're actually
71:56 . So you may be regulating how of this protein you're using by determining
72:00 much is able to bind up to receptors. That would be an example
72:04 where you might see it. But essence autocrat signaling is when you talk
72:07 yourself as a cell, Okay. all these cases that we're gonna be
72:13 at, you need to have the receptor for the message that you're
72:18 Alright, so that's just that's a rule when it comes to sales talking
72:22 each other. All right. Perricone is sending out a signal.
72:30 So here again you're releasing the signal you're talking to cells nearby. I'm
72:37 that word nearby. Next to nearby there's another term for next to.
72:44 . So what you can see again we have a bunch of nearby
72:47 right? And we have cells that receptors on both types but notice these
72:54 that are for the for this, know, just like we have over
72:57 these receptors recognize the signal. These do not. So this cell is
73:04 talking to this population of cells, have to have the right receptor for
73:09 signal in order for you to respond that don't have the right receptor aren't
73:14 and they keep doing whatever it is they're supposed to be doing all
73:17 So what you're doing is you're communicating to whom needs to be communicated to
73:23 you're dealing with cream. But the are nearby. This example right here
73:28 a neuron neurons release a chemical that going to then go out into a
73:35 space and to bind to receptors that close to or nearby that original
73:42 Alright. This is kind of it's synaptic signaling. Alright. And so
73:47 just a type of perricone signaling. type of peregrine signaling that we've that
73:53 kind of set apart is called These are the next two signaling.
73:58 it's more like this than it is this. Here, what we have
74:03 just a Quran signaling is I can a chemical message and it can go
74:07 the cell that is next to me I can be attached to that
74:11 So here it is two cells that next to each other. When this
74:16 puts this particular receptor on its it's able to connect to that receptors
74:20 the receptor on that cell. And this cell is telling that cell what
74:24 do, it's kind of like velcro have to have the right parts in
74:28 to interact with each other. This how immune cells talk to each
74:32 right? You have immune cells just through your body and they bump into
74:36 other all the time. But if have the right receptor and the right
74:39 in that come together and that tells immune cell you go and kill that
74:44 over there. Typically we were called type of direct contact. These these
74:52 of receptors are called cell adhesion molecules cams. Yeah, yeah. Process
75:00 to cell recognition. This type of right here which is a type of
75:05 a current signaling which takes advantage of junctions, which we'll talk in just
75:08 moment the two cells are connected to other and so their cytoplasm are open
75:13 each other. And so what you do is you can produce a chemical
75:18 that then flows into the next cell tells that cell what to do and
75:21 versa. This is a type of that not only uses molecule signaling molecules
75:29 also uses ions. And this is cells electrically communicate with each other.
75:36 . So I can have ions here they can move down their concentration gradient
75:40 I can change how much ion is one cell next to the other.
75:45 is your heart functions is through this of mechanism right there. Endocrine signaling
75:54 our long distance signaling. Alright, , when we think about hormones,
75:59 is what hormones do. All So, we have a chemical message
76:03 produced in one cell that goes into bloodstream travels through the body and arrives
76:08 in all sorts of different places and places you'll have cells that have no
76:13 . So the hormone isn't doing anything gets picked up back in the blood
76:16 keeps going. But in other places will arrive and there's gonna be cells
76:20 have the right receptors. Okay, give you a simple one. Um
76:26 way that when when when we're monitoring much water is in our body,
76:31 place that does that is in the . Alright. And what it
76:35 it releases a chemical that then travels a body and goes to our adrenal
76:39 and determines whether or not we need produce a hormone there that then acts
76:43 the kidney. Alright. So you see there's three different locations here and
76:48 we have are different hormones. One the brain to the adrenal gland,
76:51 from the adrenal gland of the that's quite a distance moving between those
76:56 points. The only cells that can are the ones with the right
77:03 Alright, so in all of these of chemical signaling, the chemical and
77:07 receptor matter if I release chemical It can only bind to receptor
77:14 They can't bind to receptor B. , when we do this we have
77:19 type of long this signaling, we these things hormones, hormones vary in
77:23 and type and stuff and we're gonna into that a little bit later.
77:27 for example you can have hormones that proteins or you can have hormones that
77:30 lipids and we looked at the lipids we when we threw up the
77:34 we had a picture of all the types of hormones that are steroids.
77:39 . But those aren't the only hormones exist in the body. Now,
77:46 we're gonna do is we're gonna dive little bit deeper into the molecular biology
77:51 receptor responses of this type of chemical . All right. And we're just
77:56 of dipping our toe in. so, this big word right
78:00 metabolic tropic meta bow refers to metabolic there's metabolism involved. Tropic means
78:09 So, I'm doing a type of through a metabolic pathway. And really
78:14 way this has worked. It's really basic. And this is how
78:17 lot of hormones work is I have receptor on the surface of the cell
78:22 receptor binds to some sort of signaling that's called reception. That's going to
78:27 the receptor that then activates a molecule activates a molecule, which activates a
78:32 , which might be you don't know many molecules are in this pathway.
78:35 matter. This is called transaction. you've done is you've turned an outside
78:42 into an inside signal. You've transducer message and that's where the word comes
78:48 , changed it from one type to other internal text or external to
78:53 And then, over the course of transaction you're creating some sort of molecule
78:59 becomes an activator or what we refer as an effect er because it causes
79:03 effect and it creates a cellular All right. And this is a
79:08 generic way to think about how chemically chemical messages work. I bind the
79:15 . I change the message from the of the inside and I make something
79:19 happen inside the cell alright? And I make something new happen inside the
79:24 I can either activate things. We think in terms of always activating,
79:28 can activate something but I can also something. Right? Like I can
79:34 in this room and I can turn the lights or I can come in
79:38 room and I can turn off the . It just depends on what the
79:42 is responsible for. All right. I can change the activity of the
79:47 or I can create new transcription factors behave like a transcription factor or activator
79:53 activate one. And I can change genes are being turned or being turned
79:57 . In either case, what I've is I've changed the activity of the
80:00 either what's already present or what's not and making something new appear or
80:07 Now this is a very common type transaction cascade. Again, it's very
80:12 , notice we don't have any names any molecule but you can see it
80:15 , here's my receptor, here's my in my ligand binds a receptor that
80:19 the receptor that takes one molecule and it to become phosphor elated when you
80:25 the word phosphor relation. What I'm is I'm giving energy to that molecule
80:29 do something new. I've turned it or I've turned it off. All
80:33 . And so now in this particular we're just saying we're activating this molecule
80:38 activates this molecule, which activates this so on and so on all the
80:41 down the line. So this is example of transaction that's occurring.
80:47 If you're like me when I sat your seat, you're going well,
80:49 seems like a waste of time and . Why would I why would I
80:52 a whole series of steps when I just flip the switch. All
80:57 Is that the question you're asking? nod your head. Yeah, of
81:00 . That is exactly the question I because this molecule isn't only activating that
81:07 , it's activating other molecules and it's other molecules off. So what you're
81:11 is not only are you working in pathway, but you're working in multiple
81:15 and at the same time this one may activate 10 of those molecules and
81:22 one of these molecules might activate 10 those molecules and each of these molecules
81:26 activate 10 of those molecules. And can see what we've done here is
81:30 taken one signal and I've amplified it a massive signal. So I've got
81:35 that's doing a lot of work for very, very small. So it's
81:40 amplification process as well so that ultimately cellular response is big to a
81:46 very small signal up there at the . Now, every time I activate
81:55 I have to enact or inactivate right? Because otherwise it's just gonna
81:59 going forever. Right? And so have mechanisms that allow us to do
82:04 . And these are just an example a molecular switch. Again, you
82:08 need to know these things right but this is just showing you here's
82:11 protein that's in active here. It active. So I have something that
82:17 it from the inactive form to the form. But then for everything that
82:21 it, I have to have something in activates it and this is how
82:23 regulate and control which systems are on off. So for example, has
82:29 father ever told you after you turn the light in the room as you
82:33 the room, turn off the damn . Did they use that word?
82:38 I say that a lot in my , right. I got four
82:42 they're constantly going into rooms. It's so bad. My wife is now
82:46 yelling at the kids, right? they're not young. I mean we're
82:50 , I got a sophomore in high , I mean he should know better
82:52 my daughter who was also sophomore, should know better, Right? But
82:56 idea is that you turn things on you're done with the process You turn
83:01 back off and this is how we all these processes. So, for
83:07 , if I keep activating this up , this thing will keep going.
83:12 if I only activate this once it naturally turn itself off because we have
83:17 like this in play that turned the back off automatically. That kinda makes
83:27 . So meta tropic has pathways has transaction. All right. So you
83:33 just think metabolic pathway. There's lots molecules involved. The other type is
83:40 a tropic again, tropic means to something on or off. Ion means
83:44 using an ion to do. So here what I'm doing is I have
83:48 receptor that may have a Liggan or gate or whatever it is. But
83:52 I'm doing is I'm opening up a and that channel allows ions to flow
83:57 and when ions flow that's current. when I have current I have electrical
84:02 , I'm changing the electrical activity of cell. All right, these types
84:08 responses are very quick and they're very lived. Because what I'm gonna do
84:12 I'm gonna open the channel and I'm close it back up when the ligand
84:15 opens when the ligand is let go destroyed. It closes back up.
84:19 I get a very very quick If you go back to a meta
84:23 thing, this turns on this which on this which turns on this which
84:27 on this which turns on this. you see how it takes a lot
84:29 time for it to happen? Then we have this weird one.
84:39 is what I was studying when I in grad school. Partly not not
84:43 but partly steroids and lipid signaling lipids, lipid based signaling molecules do
84:53 like water. And so what they're , what they've done or what they
84:57 to sell uses them for is they them as a mechanism to turn on
85:02 off genes. All right. So have receptors but the receptors I don't
85:07 to I mean their job is to on genes. All right. So
85:12 are what we call transcription factor. so when there is no steroid,
85:17 transcription factors or nuclear receptors hang out in the cytoplasm and the nucleus.
85:23 . But once they get bound up get transported into the nucleus of the
85:28 and they bind these regions in front the promoter. Remember what we said
85:31 promoters were? That's the start of gene. And that promoter when when
85:37 these nuclear receptors come in and bind hormone response elements. What they do
85:42 they turn on or they turn off expression of the gene. Alright,
85:46 steroids use this unique sort of mechanism change the activity of the cell at
85:53 gene level now, back up here a second. Everything in this pathway
86:00 exists. You guys see all the in the pathway. See all the
86:03 colors and stuff. So you can . I said this was really fast
86:09 it's basically ions moving back and This is slower than the ions,
86:14 it's fast because everything is already It's like lining up dominos. Once
86:18 press the first domino, all the dominoes fall when I'm dealing with nuclear
86:25 . What I'm doing is I'm making new proteins. The process from going
86:29 to a gene to making a protein time Now the example I'd like to
86:34 is a real simple one in this . How do I turn on and
86:37 ? The lights gotta switch right over . All right. So, you
86:41 imagine a meta tropic pathway is like . All I got to do is
86:44 over to press the switch and all lights go off. There's a mechanism
86:47 connects all the lights to the When you're dealing with nuclear receptors.
86:52 you're doing is saying, yeah, want to turn the lights on or
86:55 . But what I need to do I need to build the lights and
86:57 need to build the switch in order make it happen so I can make
87:02 happen. But it's going to take for it to happen. But once
87:07 done it it's gonna be around for while. That kind of makes
87:13 All right. So there is a in the response because what we're doing
87:18 we're changing gene expression. But once changed gene expression, it's gonna be
87:23 for a while long lived. The ones are not long lived. They're
87:29 very quick and they're very very short . Alright. I'm gonna pause there
87:36 a second. Any questions about Because I'm really kind of just dipping
87:39 toes into some very very complex physiological . And you're kind of sitting there
87:45 and going, oh crap, what I need to know about that?
87:47 see the look. Not my first . Are you okay with those those
87:52 ways of signaling mechanisms of signaling. can stare too. Those three.
88:09 , that's it. Okay. We're then you trust her. Okay.
88:16 right. Back to a little bit anatomy. Alright. Again, we're
88:21 dealing with the cell friday is tissue after friday is test day. That's
88:28 . Right? That's when you get take the test and then go to
88:32 . Then you get to celebrate that took the test, skip lab.
88:36 they get really upset about that. right. And then what we do
88:40 go into the organ systems. So we're gonna start here.
88:46 we're gonna finish up with the Alright. And really what we wanna
88:49 is we want to look at how are connected to each other because they
88:52 they don't work by themselves. And this little picture here shows you the
88:55 common types of junctions of the most way in which cells are attached to
89:01 another. The first type is the OEM. And really what the Dismas
89:05 is is like molecular velcro. All , you hear me use that term
89:09 and over again. But the idea is basically I have a bunch of
89:13 molecules on one cell, a bunch other adhesion molecules that recognize them on
89:17 cell. You have a whole bunch proteins that hold those adhesion molecules in
89:21 . And then what you do is gonna take a bunch of intermediate filaments
89:23 attach them to those adhesion molecules. then those two cells can then be
89:28 to each other. So that when pull on one of those intermediate
89:33 I'm pulling on this entire structure which is attached to the other cell which
89:38 on the other cell which pulls on intermediate filaments. And what I've done
89:41 is I've dispersed force. And so now holding cells close to each other
89:47 context so that when I affect oneself another, how I can ensure that
89:53 remain mechanically stable between each other go to the indian burn the reason your
90:00 doesn't go falling off your body is cells are connected by these types of
90:06 alright, They resist tension and they due stress or distribute stress by taking
90:12 force and sending it through all these into another cell which are connected to
90:18 cells which are connected to other And it kind of looks like
90:21 This is a really, really, bad drawing because cells are not connected
90:25 way. You can imagine cells are closer together. But this is trying
90:28 show you that connection between the desmond . If I pull on this cell
90:33 here, that forces distributed to this , which distributes the force to all
90:37 other cells around it. And the all move in unison and with reduced
90:48 . Yes, the hemi Dismas. is the half Dismas. Oh,
90:52 right. We're going to learn a bit later that epithelium sits primarily on
90:58 of connective tissue. Alright, that's of the ways that we see
91:03 How do those two things which are the same, stick to each other
91:06 they use things like hemi Dismas So, again, here's that
91:10 Here's those intermediate filaments. Here's those . And then you can see right
91:14 here, this would be connective And what these cams do is they
91:20 fibers in the connective tissue that they're of binding to. Again, you
91:25 not need to know specific names. do not memorize the specific names of
91:30 . But the idea here is they themselves to other molecules in the connective
91:35 . And this allows this epithelium to on a unique tissue and not be
91:41 off of it. Right? If were to create a little cut in
91:45 skin and try to pull and pull skin away from your connective tissue,
91:48 would take a lot of work You can do it. That's how
91:51 skin animals. And that's where you leather and all sorts of fun
91:55 But it's not an easy thing to . All right, So hemi
92:00 OEMs are half Dismas. OEMs they cells in epithelium to connective tissue.
92:06 what we're going to learn about the membrane when we get to the
92:12 Mhm. Don't memorize those or inte . When I was in college and
92:22 his junctions junctions apparently didn't exist. someone discovered them. And now you
92:27 have to memorize it when you see word adherence junctions, what do you
92:33 at here? So basically junction that two cells to stick together. They're
92:38 hemi Desmond zones. They just use proteins. All right. They don't
92:43 have that plaque. But again, you have is you have intermediate
92:48 you have uh molecules to which everything bound you take these cat these are
92:53 cat hearings are a type of cell molecule and they basically take them and
92:57 bind to cells together. And now adhered to one another. All
93:03 They're just structurally different. Right? he made Dismas um is sell to
93:14 tissue Desmond's. Oh must sell to at heron's junctions. Cell to cell
93:20 structurally different. And then we have tight junction which isn't or could be
93:29 it might not be. So you're learn about leaky tight junctions. You'll
93:32 about tight tight junctions and so forth . What you have to have a
93:35 of proteins that are kind of like bags. Right? Think about a
93:40 bag and sealing the little zip Right. And what you can do
93:43 you can imagine I can't go into bag and I can't go out of
93:46 bag because of that. That's basically is a series of proteins on one
93:50 and a series of proteins on the cell. And they basically are adjacent
93:54 one another and they linked to each and they create a barrier so that
93:57 environment on this side of the cell different than the environment on that side
94:01 the cell. It prevents things from in between the two cells and it
94:05 a unique space on either side. we talked a little bit. I
94:10 I said once you may not have it. I said that with epithelium
94:13 have polarity. Remember that when I that. And so that polarity is
94:19 because of this type of tight Oh I have a picture there.
94:25 it even easier to see. So there's the typical side, this is
94:30 basal lateral side over here. This they're showing you the intestine. They're
94:35 look there's stuff up there. Things leak in between the cells because those
94:39 junctions create a barrier between that environment this environment. All right. So
94:47 something wants to get over here, has to go through the south.
94:51 you don't have a tight junction then can leak through. So tight junctions
94:57 barriers Between walls of cells and two environments. There's just something else that
95:05 does and that's it's kind of unique that you see how it's kind of
95:10 pink in here. You see that pink that's there to show you that
95:15 goes all the way around the but also internal to the cell.
95:19 actually materials there. So, the side of the cell over here is
95:26 from the basal lateral side. So chemical reactions that are occurring on this
95:30 are different than that one because those junctions also create division within the
95:37 I'm not gonna ask you about It's kind of interesting when you think
95:41 if you have an apricot and basil how do they know which side is
95:45 it's because the tight junctions make it . All right. Stop multiple.
95:57 . Yes. So different environments will , you can have Desmond zone.
96:02 going into the test because this is area that I did my studies right
96:06 way the germ cells are made or find themselves in between epithelial cells and
96:13 you'll do is you can look in and you can see there are tight
96:15 , adhere injunctions, Dez Mazzone's hemi , OEMs attaching the epithelial cells and
96:21 there are junctions that actually break and . So they have all these things
96:26 as well as gap junctions so that can have communication with the cells that
96:29 next to. So it's not uncommon see multiple things. And I think
96:34 kind of how they discovered adherents are because eventually what we do is we
96:38 antibodies and stuff that we can use tag molecules and say this is what
96:41 is. And they were tagging So can see a Desmond zone here.
96:45 why is it not lighting up? that's when they realized, oh,
96:48 different molecules there. Here's the gap . Gap junctions allow two cells that
96:56 connected to each other to communicate So here this is one cell,
97:01 the other cell, a series of creates the gap junction. These are
97:05 connections, that's the group of proteins so they create a gap or poor
97:10 can open and close. And so allows the materials in this cell to
97:15 exposed to the materials in that So, if I have ions for
97:19 , they can be allowed to move through between the two cells. They
97:23 have to go out of the cell come back in a different way.
97:26 basically sharing cytoplasm. All right, the molecules have to be very very
97:34 to do. So now outside of cells we talked about there being
97:44 And so there's this guy coke So you can see here's our glycoprotein
97:48 are being shown in this picture. the truth is is that when you
97:53 at these cells, they're not just naked to the to the environment around
97:59 . There's all sorts of proteins. like we talked about there being a
98:02 of skeleton on the inside, there's of this network of proteins and other
98:07 that sit on the outside of the . Alright, even on the a
98:10 side. And again, if you watch that video um that I
98:14 you're gonna see, you're gonna see matrix because those little receptors that that
98:19 cell is trying to make in that video, they kind of pop up
98:22 you can see there's these wires and proteins that kind of you know,
98:27 fibers, not wires but fibers sitting above them and they kind of poke
98:31 of them so that they can be contact this network of proteins that's found
98:38 the cell is referred to as the cellular matrix. Alright, there's all
98:43 of stuff. There's collagen and other as well as some sugars. You
98:48 like this is a protein sugar, called google icon and you get things
98:53 glycoprotein like hands, you don't need worry about them but there's all these
98:56 types of molecules that sit out there these are secreted by the cell to
99:01 an environment that both prevent and promotes . So you have to have the
99:08 sort of connection to be able to cells. It also helps to have
99:14 environment which you can anchor cells. on the basal lateral side this extra
99:18 matrix is there to help create something you can grab onto. And so
99:23 allows for the different cells to connect each other and other and also you
99:28 see that there's like molecules like this allow you to signal with the
99:33 So you're gonna see this term come over and over again. The extra
99:37 matrix, extra cellular matrix. Just that the cells aren't just sitting there
99:42 , they actually have all sorts of sticking out from them that allows them
99:45 interact with their environment and that is extra cellular matrix. Okay, last
99:53 bit here that I want to deal is cell cycle. How much do
99:59 got here? Okay, it's just simple um This isn't like an intro
100:06 class where you have to learn every solitary step in phase and how to
100:10 them and stuff. I just need to understand that cells are capable of
100:14 . And when they're doing that they're they're when they're going through replication and
100:18 they're creating new copies new clones of . And then they can go through
100:22 periods of not division or they can they can be my topic. In
100:27 words they're going through division and then reach a point of maturity where they
100:31 stop doing that. All right. so the cell cycle represents this period
100:38 replication and so you can see it . There's two phases. We have
100:41 period that's metabolic. So that's your period. That would be you know
100:46 of how you're preparing for division and there's this period of division called the
100:51 topic phase. So you've heard of , that's what that refers to.
100:55 those steps Okay. All right. of course during the inter phase you
101:00 basically go step out and say okay done. I'm not doing I'm not
101:03 of the cycle anymore. I've been . And I set out off to
101:06 side that's kind of what I have on this side is just kind of
101:09 what are the phases metabolic phases referred as G one that's the first growth
101:15 and every cell has a different length terms of how long it lasts.
101:19 if you're still in the process of more cells or new cells there's a
101:23 called the S. Phase where you copy the DNA make you you replicate
101:29 duplicate your D. N. So that you can divide later in
101:32 mid topic phase. That's what the . Phase here. So this is
101:36 kind of a growth phase. I'm I'm getting ready to make new
101:39 N. A. I. Go make my new D. N.
101:41 . And then I go through this phase for division. Which means I
101:46 check to make sure I've gone through checklist to make sure everything's okay right
101:51 you go on a trip. Do go through a checklist? Did I
101:54 the doors and I packed enough Do I take sunscreen? Do I
101:58 my ticket? That sort of Right so that's kind of the same
102:01 that goes on here. There's a of checklists that the cell goes through
102:05 it says have I done everything correctly in order for me to go here
102:09 once I enter this if anything's busted get to die. And so it
102:15 to make sure that that doesn't All right. You also have that
102:22 . G. Not phase. That's that zero is G. Not and
102:25 that's the one where it just kind hangs out and says I'm done I'm
102:28 gonna do the thing that I've been to do. All right So I
102:32 the checkpoints. Um there's one here the G. One and then there's
102:37 couple in the G. Two. And again just understanding that I'm I'm
102:42 checkpoints to make sure that I'm able progress in the next phase is
102:46 It's kind of like lack of better like graduating from high school and graduating
102:51 college right? There's a checkpoint that have you done all the work you're
102:56 to do? You have? Okay you go. So mitosis is the
103:03 of the nuclear material. Psychokinesis is division of the cellular material. Okay
103:13 there are four phases. You don't to recognize what these things that are
103:19 in these phases. I'm not gonna you that. It's just mean alright
103:22 just under I mean at some point life you learn it MAC pro fes
103:25 face to face to face. Did guys learn that one point? Did
103:29 have to look at the picture of cell and draw the little stages at
103:31 point? Yeah. So just understand I'm doing here is I've already replicated
103:36 D. N. A. During interphase. In pro phase. What
103:39 doing is I'm organizing that D. . A. So that I can
103:42 it Between the two daughter cells. right so it's the latter two phases
103:49 that DNA is being pulled apart and ultimately being reorganized. And then psychokinesis
103:55 simply saying look I've separated at the of the D. N.
104:00 And now what I'm gonna do is gonna split the material of the
104:04 So I have two identical copies of cells that are now clones of each
104:10 we call them daughters. And then capable of doing what the parental cell
104:14 doing. Initially we tired. I can keep going. I'm not
104:27 . Alright so that's where we're gonna today when we come back. Unless
104:31 really go like off the reservation it's be a pretty short lecture. I
104:37 know if it's it's probably gonna be little bit more than ours. We
104:39 not break. But historically going through different types of tissues is pretty
104:45 So you guys have a great I will see that's tomorrow.
104:53 You guys have a great day. you tomorrow. Have a wonderful
104:57 Don't burst into flame. Bye bye
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