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00:02 Alright, y'all here we are in very wet Tuesday, continuing our discussion

00:08 channels and other fun stuff. And what we're doing is we're looking at

00:14 some just kind of specifics about the structures that allow ions to move

00:19 and forth across memory. That's how gonna start, because that's where we

00:22 off last week. And then what gonna do is we're gonna move into

00:27 signal works in the cell. In words, how do cells talk to

00:32 other? That's kind of the big going. And so here we are

00:36 this point here, looking at pores channels and actually there's a question someone

00:39 me at the end of class so what exactly is a poor and

00:42 just didn't happen to get to And so a poor simply is a

00:46 that has no gate or door and going to call them gates because that's

00:50 we define them in biology. So basically it's an open channel that allows

00:54 to pass through. And at some in your career you've probably heard about

00:58 porn's Yes, Right. That's a pour, that's literally what it

01:02 And so a water pour is just channel that allows water to go back

01:06 forth easily in and out of the . So whenever you hear poor,

01:10 think, oh, it's a but it doesn't have a gate.

01:13 things move down their concentration gradients through poor. A channel on the other

01:18 , even though it's the same it actually has a gate that regulates

01:23 passes through it. All right. so what we do is we refer

01:27 its modality. What is its The modality is simply the thing that

01:31 and closes the gate. And so here's a couple of examples of

01:36 We have chemically gated voltage gated, gated. There's thermally regulated channels as

01:41 . So there's all different types. really you can just think of this

01:45 a key. What is the key opens the gate that allows the things

01:48 pass through? And so with chemically , that's the easiest one to

01:52 You can imagine what binds to the A here. I'm gonna underline the

01:59 again, a chemical, right? so that basically says some physical

02:07 some little element or an actual chemical along, that serves as a key

02:11 opens the door. That's an easy to visualize, right? Alright.

02:15 weirder ones, the harder ones are voltage gated and hear what you're doing

02:20 the channel itself has charges around And so when the differences of the

02:26 on either side of that channel start , that's gonna change its interaction with

02:32 environment and it changes shape and that's it opens up. All right.

02:36 these voltage gated channels are really, important and valuable in understanding how muscles

02:42 neurons work. And so you'll see come up over and over again mechanically

02:46 i thing, they're they're kind of to conceptualize. but it's still not

02:51 as easy as I take a chemical open the gate here. What we're

02:54 is we're manipulating the environment around the . When you manipulate the environment,

02:59 twisting and turning and stretching and stuff causes the channel to be affected by

03:04 twisting the turning. So it changes and so it opens up as

03:07 So like when you get a pinch when you feel a poke, those

03:11 mechanically, you're mechanically manipulating cells that these types of channels that allow ions

03:17 pass through. All right now channels pores are very, very small and

03:24 very selective as to what they allow and there are hundreds of them.

03:30 news. We don't need to know . All right, but they're very

03:33 . So typically what we'll say is look at a channel and says,

03:36 this channel only allows sodium to pass ergo it is a sodium channel,

03:42 ? If it's a voltage gated sodium which basically pointing to its most

03:47 Alright, so the idea here is the channel has a specific side.

03:52 you guys have all taken chemistry. you should know the answer which element

03:56 bigger, potassium or sodium potassium is . Yeah, I know it's kind

04:04 scary when he throws stuff out at like that. Right? It's like

04:08 you mean I have to remember right? So potassium is bigger.

04:12 you think oh, when I have potassium channel wouldn't sodium be able to

04:15 go right on through because they're both the same valence. They sit right

04:18 the same column, right over there that far left, right. The

04:22 is known. It's because of the of the electrical charges. So you

04:26 think of it kind of like as magnetic field that repels and attracts and

04:30 if you're the right size, you go through. But if you're the

04:33 size out you go, you don't to go through. So that's why

04:37 have that degree of specificity to All right. And notice these are

04:41 dealing with ions very, very small . If you're bigger like a glucose

04:46 and glucose is really small, relatively , you're gonna need something different.

04:51 forgot I had to push the Sorry, when I go into two

04:55 programs, you know, it doesn't . So here's that carrier and this

05:01 of visualize is what we were talking on thursday. It's like it's never

05:04 to both sides at the same Just like that rotating door at the

05:08 , right? You have a binding that that particular molecule that needs to

05:14 carried across the membrane combined to when chemical binds to that binding site that

05:21 the change in the shape of the . And so this is just trying

05:25 show you the different stages here. am outside here I come in and

05:29 I'm bound. So now I change . I reorganized. Now I'm open

05:33 the other side and now that I'm to the other side, I have

05:37 affinity. I still have affinity but affinity. So out the molecule goes

05:42 longer bound. So then I flip to the original shape and so this

05:45 me to move materials in very specific . Alright, so we never have

05:50 continuous passage and we're moving molecules in particular direction but we do it a

05:56 slower because it's not just a channel we can just flow through down a

06:00 . So you can imagine over here got lots of these whatever that happens

06:04 be. And on this side I very little. And so there's that

06:09 that's driving the molecule down its concentration . But we use this as a

06:16 because these are bigger items. it's not always gonna be bigger

06:20 it can be ions and we'll see example of that in a little bit

06:24 . Now when you're dealing with carrier transport. So that would be this

06:29 a carrier. Right? So this an example of carrier mediated transport.

06:33 gonna have some rules that kind of with this. You have specificity not

06:37 molecule combined, that binding site. it has to be specific. Sometimes

06:42 molecules are very similar and they combined the same site. And so then

06:46 you have that then you're going to up with competition? All right,

06:50 guys ever play musical chairs? one chair. Two butts.

06:55 so one of those butts is gonna the chair the other but is gonna

06:58 all by its lonesome. And that's what happens here. You don't get

07:01 share the chair. And so it's now you're kind of fighting dependent upon

07:08 . Right? So if I have of this molecule intent of this

07:11 that carrier is likely gonna carry this with greater frequency than this one.

07:17 ? But if I change concentration so equal there's an equal chance that both

07:22 molecules will pass through that particular Alright. And there's a point of

07:28 in other words, um if I 10 receptors or 10 channel, excuse

07:32 . If I have 10 channels and have one molecule, I can move

07:35 molecule pretty quickly. Right? Cause 10 options. If I got to

07:39 can still move it at the same . Once I get to 10 molecules

07:43 10 molecules for 10 receptors, I'm start reading reaching a saturation point because

07:48 of those molecules now is going to fighting for one Channel. So if

07:54 have 100 of them there's gonna be right, basically everyone wants to get

07:59 but there's only 10 doorways into the . Right, so understand that when

08:04 looking at these that these these mechanisms carriers were dealing with these questions of

08:11 what is the specificity? What do have here? Oh yeah, glucose

08:14 galactose. You guys remember those two ? Right? Can you visualize them

08:18 exposes? Look awful lot alike. groups are switched into positions. You're

08:24 of like, I don't know about . Go back and check it

08:26 All right, you can actually google up and I'll show you the line

08:30 . You don't have to do that now. But if you look at

08:33 , you'll see, oh wait a . Yeah, there's a flip

08:35 So they're very similar. So they they can compete for the same binding

08:40 . Right? So that's the Notice here, the rate of reaction

08:43 a little bit slower because of that . And then saturation. There's a

08:49 or specific limit to which I can . All right. Now we get

08:55 the weird stuff. The active When you see the word active,

08:58 do you think of energy? Okay. So when we're dealing with

09:04 usage, what we're saying is we to use energy to move something in

09:09 direction, it doesn't want to If I put a ball on a

09:12 , it wants to go down and the floor. Right? And so

09:16 I gotta do is apply a little energy just touch it and that thing

09:19 roll and fall to the floor, no other work that needs to be

09:23 . But if I have the ball the floor and I want to put

09:25 on top of the um uh cabinet shelf, I have to do

09:31 don't I? Right. See what our physics one. So we learn

09:35 , right? So energy has to applied. Now I can apply energy

09:39 and do the work. Or I apply energy indirectly and do the

09:44 In other words, the machinery that's the work. So, when I

09:47 over and lift it up and put ball on the shelf, I'm using

09:51 directly. Or what I can do I can put energy into machine and

09:55 machine does the work. Right? , that would be an example of

09:59 versus indirect. And so we have that are both direct and indirect and

10:05 just refer to the direct system as active transport. We use the indirect

10:10 active transport. Now, I'm gonna you the primary is easy,

10:16 Sometimes it takes a little bit of moment to wrap it around, wrap

10:19 heads around the idea. All But that's the idea. We're moving

10:23 in a direction. They don't want go. Alright, so, I'm

10:27 just show you pictures here to make lives simple. These are just the

10:30 to support what we just said, potassium 80 pes pump. You have

10:35 this one. You know when we're things on our body, like caffeine

10:38 stuff. This might be one of things you want to consider because you'll

10:41 it all the time, Right? here what we have is we have

10:46 lots of sodium on the inside of cell and we don't want to get

10:50 of it so that there's little sodium the inside. We have lots of

10:53 outside the cell. We want to it on the inside of the cell

10:56 we can get to our natural state of equilibrium and homeostasis where we have

11:02 heavy on the outside, potassium heavy the inside. So this pump does

11:07 job. So what I'm gonna do I'm gonna take three sodium, I'm

11:10 bind to this carrier. When that . What's gonna happen is it's gonna

11:16 shape and with a T. It allows it to change shape so

11:19 I'm moving it and then I create two new binding sites, potassium comes

11:23 and then it changes shape again, moves in. So at the expense

11:26 1 80 P. I can move move sodium out of the cell.

11:30 gonna move potassium into the cell. , now, if you want to

11:34 what that actually looks like. This the process, there's multiple multiple steps

11:39 this and it doesn't matter where you um we're just gonna start up,

11:43 see what the best place to start period. Okay, So what we're

11:46 do is you can already see A . P. Is bound up to

11:49 molecules. So it's ready to We've already primed the system. We

11:52 the energy there. We just got release it. We have the binding

11:55 for sodium sodium binds into it. causes conformational change so that sodium goes

12:00 . The new the new binding sites created as a result, the picture

12:05 tell you exactly what's going on. three sodium binding sites are right on

12:12 of the two potassium sites. So can't buy them both at the same

12:16 , right? They take up the space. That's why they always draw

12:20 separately so you can visualize it. that's why if you ever wonder why

12:23 can't I just do it at the time? That's why. Alright.

12:27 as Yes, sir. Uh Well rule no, and the reason for

12:38 is because look at what the Does it just does exactly what we

12:41 to carry to do, right? never open to both sides at the

12:44 time. So once I bound myself it, look what happens, I'm

12:49 closed on both sides. And then I'm open only on the outside.

12:53 even if I'm released from that right, I only have one

12:57 I can only go one direction. ? So if I if let's say

13:02 your eye can see kind of a bit what you're thinking here in

13:05 I can go back and forth. . So if I get released,

13:08 I buy into that site while I'm open to that side? Sure.

13:11 I have less affinity so I'm less to. And also I have no

13:16 . That's the only way I can . And I'm not going to be

13:19 to create those potassium sites until both leave. Yes. In this particular

13:29 this particular pump. Yes. Absolutely. That's correct. Alright.

13:35 so you can see here now once potassium, excuse me. Once the

13:39 have left now we have our potassium . Just imagine on the same

13:43 And so now the potassium comes in wants the potassium by that's what causes

13:48 d phosphor relation the release of the to turn it back the other

13:53 and then these are just the opposite . Alright, So, I think

13:57 a pretty easy example to see. , Yes, ma'am, Prime

14:05 It's so, you can see it's gonna be in this case it's

14:09 be to return the potassium to the to return to its original shape.

14:14 , if you look here here, see nothing bound up. Right?

14:18 , what have I done is I've started the movement from the opening to

14:23 outside to now opening to the inside once I've opened back up to the

14:27 , that's when I can prime it the fresh A. T.

14:30 That hasn't been hydrolyzed yet. All , so the idea here is the

14:36 ation of a teepee occurs here to me to change shape. And I'm

14:40 trying to see actually it looks like occurring there. My my mistake.

14:44 obviously I'm not gonna ask you that . That's a just so you

14:47 that's a cell, bio bio kim molecular biology question. I'm not gonna

14:52 you what are the steps I'm wanting to understand the process because we have

14:57 of these pumps in our body. right, let me show you the

15:02 one, you ready now as a of this, I've pumped a lot

15:06 sodium on the outside of the I've pumped a lot of potassium onto

15:10 inside of the cell when I moved in a direction they don't want to

15:13 and they've accumulated. I have created energy, right? If I put

15:18 whole bunch of ping pong balls in closet, where do they want to

15:23 when I open the door out of closet? Right, So we have

15:27 stacked up trying to move down their gradient, there's just no mechanism that

15:32 know of, right? This second allows us to do that. All

15:36 . This is where secondary active transport in. It's basically storing up energy

15:43 a concentration gradient so that I can something against its own gradient.

15:49 so the example that we have here there are lots of these little systems

15:53 the body that allow us to move that wants to go into the cell

15:58 with sodium. Now the example I use is this year's. I hope

16:02 . Okay. I don't want to on your pencil. No,

16:04 don't don't worry about it. I'm getting out of the way. Um

16:07 gonna use an example that's not gonna everybody here. All right. But

16:10 worked for me for many years and I'm just sticking with it so you

16:14 just shake your head at me and go whatever. Doctor. Alright.

16:17 went to school in New Orleans went late. I think I told you

16:20 this. Maybe not. If I I went to school in New

16:23 why do you think I picked new ? You can say I see the

16:27 on your face. Go ahead. fun. All right. I

16:32 it's a fun city to live There's a lot of social life you

16:36 do and in fact every day of week, there's a ladies night at

16:41 bar around the university. So, , if you want to drink,

16:44 you gotta do is show up to bar that has ladies night and usually

16:48 can get in for free and usually guy's gonna buy you drinks.

16:53 how's that gonna happen? Well guys to pay a cover charge to get

16:56 these places man. I don't want pay a cover charge but I can

17:01 in free if I bring in a . Right? So what happens is

17:07 outside the bar there are single women single guys are usually in groups and

17:12 like, hey man I want to in. I've got a friend in

17:15 , I want to go hang out but I can't get in, I

17:17 want to pay the $10 cover or it was at the time. It's

17:20 like $4 and that was still outrageous the time, you know? But

17:23 like I want to go in if come in with me I will buy

17:28 a drink and then we'll call it . So you see what happened?

17:33 gets her free drink, doesn't have pay for drinks that night. I

17:36 into the bar and I can hang with whoever I do. And maybe

17:38 might actually get a phone number. what this system is right here,

17:44 ? sodium wants to go on the but it doesn't have a mechanism to

17:48 . So glucose needs to get in cell but is moving uphill. It

17:52 do so and I don't want to energy to move energy because as far

17:56 sales are concerned, what's glucose? a whole bunch of energy. How

18:00 energy do you guys remember? 38 P. Yeah 34 to 38 80

18:06 . Alright so it's saying I don't to spend energy to go into the

18:11 . What I'm gonna do is I'm , hey sodium I see that you

18:15 to go in um If you take in with you we both get what

18:19 want and that's what this mechanism It's showing you this. The potential

18:24 of sodium wanting to move into the allows for glucose what to move against

18:30 gradients to get into the cell. I don't spend any energy doing so

18:35 . I mean I still use up energy now. This is true for

18:40 whole bunch of different systems. Much your sugars and amino acids use

18:44 So think about all the digestion that do. Think about what's in the

18:48 that you digest, that amino acids . Not your heads go. Yes

18:53 I eat proteins. Do you eat of things with sugars and you break

18:58 down into glucose, galactose and Guess what if I want to get

19:02 across the board, I'm gonna have have a system that allows me to

19:06 it without expending energy. And this what allows me to do that.

19:11 primary active direct use of energy. . T. P. Aces are

19:15 be associated or part of the channel you're looking at secondary active transport.

19:20 using the potential energy created by the active transport systems that you have.

19:35 . Yeah. So, the active is here. Right. So,

19:39 did I do? I expended energy move three sodium against it's gradient and

19:45 to potassium against it's gradient. the expense was in order to store

19:50 the ping pong balls in the I expended energy, right, I'm

19:54 sodium over here. I'm expending Now, the energy is in the

19:58 of stored up sodium outside the cell wants to get in and similarly stored

20:04 potassium wanting to get out. So, you can think of

20:10 That's a good way to think about gradient represents the difference. So,

20:15 amount of energy you actually have stored . Yeah. Uh in the pump

20:30 this case. Yes. Well, remember I said in this over

20:34 in our starting position, you we have less sodium, but I

20:39 , we have more sodium out So, we're always moving against the

20:41 . When you're talking about a both sides are moving against the

20:45 And so this just shows you the . So, so the end result

20:50 , is you're gonna end up with attack um on the outside of the

20:54 . More potassium on the inside of cell, you're gonna end up with

20:58 sodium on the inside of the more sodium on the outside of the

21:01 and now you have a gradient that to drive sodium back into the cell

21:06 you have a great that's gonna want drive potassium back out of the cell

21:12 you're using a pump, that's that the case, yes, but the

21:15 inclination of any sort of chemical is move which direction down its gradient,

21:20 down the gradient. So remember against going uphill. So, I think

21:25 I get out of my bike, I want to go up a hill

21:27 do I want to go down a ? Down the hill? That's the

21:30 you want to go. All right , the put your hands in your

21:35 . Do not write these things down because I know every one of you

21:39 to memorize all of these molecules. not. You have now learned conceptually

21:46 hundreds of thousands of molecules really just of molecules that exist in your body

21:51 allow you to move things back and across membrane. One term we use

21:56 called a co transporter. Co transporter to objects in the same direction.

22:01 does this kind of look like? active transport and secondary active transport?

22:09 moving to things in the same Alright, sometimes you'll see the term

22:13 porter, all the salts are moving the same direction. It's a secondary

22:18 transport system. These are all examples types of of of these coats transport

22:25 that your body uses. This is an exhaustive list. These are the

22:29 common ones. Alright. So, you see something pop up like a

22:33 chlorine co transporter. You go Okay get that here. There is the

22:36 I mentioned, the sodium amino acid transporter. Oh I'm using sodium to

22:41 me move my amino acids. That's concept. When you see something

22:46 you can then memorize the specific We also have exchangers here. This

22:51 another type of secondary active transport here moving in opposite directions. So once

22:57 sodium is moving down its gradient but acting as the pump energy to move

23:02 calcium in the direction. It doesn't to go. Alright so sodium is

23:07 in because it wants to move calcium is moving out even though it

23:10 want to. Alright, you're going a second but it's the same mechanism

23:14 we saw with the active transport. differences were not using energy directly.

23:20 . We're using the energy of the the stored energy of the sodium.

23:24 potential energy to drive the pump Okay. And you can see there's

23:29 lot of different ones and typically what doing is we're gonna be exchanging a

23:32 eye on for cat ion or an eye on for an an eye on

23:36 we're not changing charge what we're doing changing which so happens to be inside

23:41 outside the cell. Alright. But idea here is what are my

23:48 Right? This case is gonna be chlorine. You're gonna see this bad

23:53 a couple of times? I love picture? This picture. Picture makes

23:59 excited. So does this one. ? Because this shows you everything you

24:05 learned again. Do you have to all these right now today? Am

24:09 gonna test you on every one of ? No, because you probably have

24:12 seen an enac channel. But what shows you is that, oh

24:17 here's a channel Enac. You can of guess. So it's electrical sodium

24:21 really what it stands for and there is. There's sodium goes in so

24:24 a volt educated channel. When I the channel, sodium comes in,

24:27 are often named for what they look . Here's uh well, I want

24:33 show, I guess they don't have up here. They have circa.

24:36 , Circus is a channel. You're learn it when we get to the

24:40 , you hear circuit and kind of you scared Like what is a

24:43 A circus, no circus, smooth , plastic particular calcium channel circa It's

24:50 , oh, those stupid abbreviations. that's what all these are. If

24:55 look at them, calcium channel, that a little any different than that

24:59 ? What do you think? it's calcium and sodium. Yeah,

25:04 structurally. Are they different? the cartoon even shows you and I

25:07 it's a cartoon. But basically, , they behave the same channels or

25:11 or channels. It just depends on what's the modality? Right? What

25:15 and closes it and what does it through? This is the picture that

25:19 book uses for a pump. It like a bell. Anything different between

25:22 two pumps. Other than the actual not even the materials ones on the

25:26 membrane ones on an organ L. . They behave the same way because

25:29 a pump when you hear the word . What do you think of active

25:35 ? I'm burning a TP to make happen. And what am I

25:38 I'm pumping calcium in in this case protons out over here pumping calcium out

25:43 the cell. Protons into the Right? Here's our coach transporters in

25:50 . C. C. Is a one. Sounds scary. But sodium

25:55 chlorine chlorine in K. C. . Right? proton channel. How

26:01 that different than those channels? It's it's just what allows to go through

26:07 . All right. So, my in showing you this is not to

26:13 is to start seeing the pattern when see the pattern. All of a

26:18 everything is gonna start becoming easier and and much more fun to understand the

26:26 when you going to learn a specific . And you're going okay? Now

26:29 see this is just like the one just looked at another system. It's

26:33 a different molecule, but it behaves same way you're golden. Okay.

26:38 right. I don't know how long took to get through all that

26:42 But now we're on the official third . Any questions so far that we

26:48 get? Yes. That's just kind the general terms we use.

26:58 And so if I went back and mean, just showed you um like

27:02 this exchanger, right? I we've got a driver here that's moving

27:06 down its gradient and it's carrying with bicarbonate against it's gradient is carrying chlorine

27:11 it's gradient and that is those are the opposite directions. And so,

27:14 we're doing here, we call this exchange because of the number of

27:18 right? In which direction they're So, you can refer to them

27:21 anti ports or you can refer to as exchangers, I think really in

27:26 college level books, the use the that basic term, the anti import

27:31 I don't know why. And then you get up to the professional level

27:34 , they refer to them now as . So, there's something in terms

27:38 the language that changes, right? co transport just means I'm moving two

27:43 at the same time. I just to know which way. And if

27:46 look at the word it will tell which way they're going to deport or

27:49 ports. You know, Exchanger or general co transport? No, we

27:58 talking or have talked about the small . Let's get to the big

28:03 That's all right. You know, get to the big stuff. How

28:06 I move big things out of my ? Alright. Because moving small

28:11 we have channels and carriers. But got proteins and proteins are huge.

28:16 monstrous. And so what we have we have what is called the Secretary

28:21 . So what we're doing here with Secretary pathways, we're putting things either

28:26 the cell or we're putting them into membrane. Right? So when we're

28:31 about those channels, those channels got that membrane through some sort of

28:35 they didn't just magically appear there. what they did was they used this

28:41 what is called the Secretary pathway. so the gist of it is is

28:45 if it's soluble something that you need secrete what you're gonna do is you're

28:49 be always inside the organ el and what you're gonna do is you're gonna

28:53 moved to a vesicles and then that will ultimately merge with the plasma

28:58 And then whatever that soluble protein it's been secreted out of the

29:03 All right. If you are a protein, something that is supposed to

29:07 in the membrane, what happens is you are tagged and actually as you're

29:13 made, you are inserted into the and then as you go along and

29:17 you're sorted, you're actually staying within membrane on that vesicles and eventually I

29:22 this one actually shows a couple of right there, the little yellow dumbbell

29:26 things. And then once you get there now you are in the membrane

29:30 the portion that is supposed to be outward while you're making it is facing

29:35 the organ l right, so that it comes to the surface, what

29:38 doing is you here's my organelles or my vehicle, I merge with the

29:45 . And what happens is is I up this way and so now I'm

29:48 the right direction. Alright, so way you can help yourself remember,

29:54 is like the inside of the like the outside of the cell.

29:58 not but it's like that. right, so we can make things

30:04 one of two ways I can regulate or I always make it okay regulator

30:10 always make it when I'm regulating something means the materials are still gonna be

30:15 all the time. But when it's to release it, some signal has

30:21 come along. So in our little over here, what they're trying to

30:25 you is they're trying to show you vesicles that's hanging around, full of

30:28 the stuff that it's going to secrete you need to have some sort of

30:33 or some sort of signal that comes and says it's time to merge that

30:37 to the plasma membrane and now, it moves to the plasma membrane then

30:42 can open up and release its So that would be a regulated

30:46 the constituent tiv is that you're always a pathway that's always turned on.

30:52 always making stuff, always putting things the vesicles. But the vesicles are

30:56 moving to the surface of the cell releasing its material. Alright, So

31:02 this constant production. It never slows . All right. Now, when

31:08 say this, I'm kind of reminded we're gonna see when we talk about

31:13 digestive system. For example, you produce the pancreatic enzymes are always being

31:19 in the small intestine. It's always the same rate until you put put

31:23 in your body, in which what do you think it does?

31:27 increases. Right. And then after food gets all digested and stuff,

31:31 the enzymes returned back to that original of rate. So its constituent of

31:38 . What do you think? It like it doesn't it? Yes,

31:43 it's regulated at a different area. what I want to point out is

31:46 this is being regulated here at this . Right, I already made this

31:52 . I've stored it away. I'm to release it when we're talking about

31:56 of your regulating up here in the . Yeah. Right. So,

32:05 it's it's a compare contrast between these . Right? So regulated at the

32:10 of secretion here, We're not regulating the level of secretion. If we're

32:15 at all, it's gonna be the of transcription, right? So I'm

32:21 more so that I release more. so that's where the levels, So

32:27 the difference. Like I said, enzymes never stopped being made in your

32:31 track. Or really, it's in small intestine. Always always always

32:35 Which is why you can always eat . That's why I'm always hungry.

32:42 right. So, what I'm trying draw us into is, yes,

32:53 . So, for the constituent Yeah. So, so in

32:58 it never stops. It can get a low baseline level, but you're

33:03 always making you can ramp it But if you ramp it up,

33:06 not you're doing it at a at level way up here. You

33:10 Like I said at the level of the product, not at the level

33:14 releasing the product. So, right , I'm just gonna give you an

33:17 . This will land for some of may completely miss the hormone that regulates

33:22 steroids. Alright? So that we're about follicle stimulating hormone and looting.

33:27 hormones are always being made. Always peptides and their only released when the

33:34 signal comes from the hypothalamus to tell pituitary gland time to release the

33:39 All right, So that means they're being made at a relatively constant rate

33:46 , we can accelerate that rate and can decelerate the rate. But we're

33:50 making, right? But the rate release, that's what we're regulating,

33:56 what were we talking about, regulated we're talking about that. When do

34:00 release it? It's already there, got to do is give you the

34:06 signal and out it comes. We get the reproductive system, we

34:11 to learn that one which is a lot of fun. Oh, by

34:14 way, I'm a reproductive biologist, I get all giddy around that time

34:17 year, it's like Yeah. So what I'm trying to get to

34:22 trying to get to vesicular transport these and we do a terrible job teaching

34:30 vesicular trans. Anyone here have dr for general bio or I mean,

34:34 intro bio. Did she get real about these vesicles? Yeah, because

34:37 studied this stuff and so she actually into depth but everyone else doesn't because

34:43 else kind of like, it's just physical and that's okay and I'm not

34:47 to be the world expert in all either. But what I want to

34:50 out here is the secular transport simply a way to move very, very

34:54 substances that can't pass through a So we're gonna do is we're gonna

34:58 it into this membrane like structure. it is made up of the same

35:02 , a Plaza membrane. It's capable merging with the plasma membrane is part

35:06 a larger system which we refer to the indo member Nous pathway or the

35:11 membrane system. So basically everything from er to the golgi through the vesicles

35:16 to the plasma membrane is kind of same system. And so when we're

35:21 these large peptide large proteins, we this big structure. Now they don't

35:26 float around. Like when you look the pictures of them, they kind

35:28 get the sense that they're like bubbles through like fluid and that's not the

35:33 . They're actually being dragged around by and dining these little tiny proteins that

35:39 energy to move them along specific tracks get them to where they need to

35:44 . So A T. P. going to be involved in this.

35:47 then we have specific terms we use we're describing different types of processes involving

35:53 for example, we have a type intake that's referred to as fagot

35:58 which is the term we all heard least once, right? But we

36:02 have endo psychosis and exocet. sis psychosis is to take in where

36:07 closest to take out these are more less opposite. This is a unique

36:13 that's specific for a specific type. when I was in college we didn't

36:17 these differences, they just refer to or the other but as we get

36:21 we get smarter or as I guess passes, we get smarter. So

36:24 give things new names. And then makes classes like this more complicated.

36:29 , so how do we do All right, Well, first off

36:32 have a plasma membrane that wants that want to bend. It wants to

36:35 kind of flat and so we gotta we gotta bend it. And so

36:38 have proteins that play a role in . All right. And these are

36:42 classroom molecules and your customers. So probably heard of classroom, you may

36:46 have heard of a customer. But they're basically proteins. That kind

36:50 do the same thing. What they is they force the membrane to kind

36:54 bend on itself to create that round . Alright. And so this kind

36:59 show you the process from endo Basically what we've done is we've we've

37:04 a whole bunch of molecules we want bring in using these receptors that's that's

37:09 in the classroom which is represented by little triangle scary looking things. And

37:15 it's done is bent that membrane and of pulled it in and now created

37:19 round vesicles. And then what they is they recycle themselves and they go

37:22 and can do the same thing and you have this vesicles with materials trapped

37:26 them that you can then use the inside or transported or whatever it is

37:32 you're supposed to do with it. , you can have molecules that have

37:36 classroom on them um to form, them off the Golgi for example,

37:41 the same thing and then you recycle . And I think I have a

37:44 of that showing you showing this as . So this can occur both for

37:49 or exocet. Oh sis. So first step is to create the vesicles

37:53 using these unique proteins. The second is directing it and again it's really

38:00 to get lost in the minutia Alright, but what I want to

38:03 you is that when we said that regulated the vesicles again aren't just floating

38:08 , they're transported right up next to membrane on which there are many proteins

38:12 are located. We call these proteins as snares and there's proteins that are

38:20 with the with the vesicles. Their are associated with the plasma membrane.

38:24 one is called the the V snare the vesicles. The T snare is

38:28 the targets that would be on the membrane. And basically you can think

38:31 it as a place where these things dock. So there's like this is

38:35 you need to go. So they and they sit and they reorganize themselves

38:39 such a way that the two membranes almost ready to open up and join

38:43 each other but they're not allowed to the right signal comes along to let

38:47 happen. So that's what's happening here we're seeing the the vessel being docked

38:55 it's kind of stuck in this position the right signal comes. Once the

38:59 comes in you see the merging of membranes materials inside the vehicle are released

39:05 then we have to recycle everything because cells are very very green and they

39:09 everything. And so what they're gonna is they use another series of molecules

39:13 are collectively referred to as the snaps basically say let's move you all to

39:17 next spot and get this going. so you imagine if I'm moving a

39:22 of molecules energy dependent, right, want to know where all your

39:26 T. P. Is going. not to move your muscles. It's

39:29 you have so many of these little things going on in your cells all

39:31 time. So snares let me direct the vesicles need to go. Let's

39:37 doc that vesicles until the time of is necessary and then the snaps helped

39:42 dissociate all those proteins so I can them and now that vesicles now part

39:47 the plasma membrane. Yeah. So yes, so that's kind of

39:59 purpose of the of the of the is to get all those parts and

40:03 them off to where they need to . So the V. Snare portions

40:06 redirected back to the golgi so that can you can actually rebuild your

40:10 The T stairs are redirected back to plasma membrane so that they can create

40:14 new docking site and then what you're is you're now ready for the next

40:18 to be formed. Alright now we're see this when we over and over

40:24 when I get when we get to muslim, I'm gonna point to and

40:26 do you see how they're so closely ? So closely associated? All

40:32 And what this picture is just trying show you again is is the different

40:37 of endo psychosis that we have. we have I'm gonna start with the

40:44 was common one, the one that's to understand receptor mediated apoptosis. And

40:49 just gonna make sure where this that's uh okay, that's fluid phase.

40:54 I think this is this is the I'm just trying to look at the

40:59 so you can see on the surface our side we have all our little

41:02 , things that look like a little upside down wise. So those are

41:05 receptors saying here I am, I'm looking for the thing I need to

41:07 . All right. And so what is is when things bind to those

41:12 , what that's gonna do is you're to have those receptors go, oh

41:16 bound. And so what they do they move and affiliate and associate with

41:20 other into kind of a clump. a real scientific word, right?

41:26 basically it's like, oh I've found . So I'm gonna go hang out

41:28 the things that have bound something and that is what attracts in the

41:32 So again, there's machinery that we're talking about. So the classroom comes

41:37 and that causes that flat membrane to inward and ultimately form the vesicles.

41:45 binding something because the fiber receptor, specificity, and what I'm doing is

41:52 now focusing in on bringing that thing the stuff for whatever purpose I have

41:58 to transport it or use it or that would be receptor mediated.

42:05 so, again, I have, , this is the way you can

42:08 lots of substances. The next most or easiest to understand is probably pinot

42:14 or what is called fluid phase into , which is being shown over

42:17 in essence, what this is, the classroom or the customers or whatever

42:22 shaping molecules are. The, what do is they will congregate the plasma

42:27 and what they'll do is they just that imagination again, and then pinch

42:31 whatever happens to be in the surrounding . So, what we have here

42:37 just random. That's exactly right, random. So you get what you

42:41 and you don't throw a fit, ? And what you're doing is they

42:44 it pinot psychosis. It's sell I'm just pinching off whatever I can

42:48 off, you're actually not reaching you're actually in vaginal waiting.

42:52 whatever happens to be in that thing I finally close off that vesicles,

42:56 what you get. And so it's very non specific thing, you don't

43:00 what you're getting. But whatever materials pick up, you can use recycle

43:03 move whatever the case may be. then we have this weird one

43:07 you know, I'm glad they're throwing to books. Just just confuse us

43:11 . It's called photosynthesis. It was discovered in capillary epithelium and its primary

43:17 is to move molecules from one side the capillary to the other.

43:21 And we haven't talked about capillaries. it's not very helpful to kind of

43:24 this without taking a little bit of . But basically what it says is

43:28 there are there are holes in capillaries most material can move through naturally.

43:32 kind of like, like the holes my fingers here. But those holes

43:36 still too small to move big things if I want to move a big

43:39 , I need to transport it across very very, very thin cell.

43:43 so why don't I just form a way forward by doing this. And

43:48 is where they discovered um uh cal in which is a one of these

43:53 again, shaping molecules and it creates special pits that allow you to transport

43:59 from one side of the cell to other. And again, remember the

44:02 are very, very thin. So kind of create big giant gaping pores

44:06 for the one thing you're trying to . All right, So it's very

44:10 to the receptor mediated psychosis because your for what you're trying to find.

44:16 at the same time it's, you , different mechanism. So they're throwing

44:23 book just to make us confused. ? But as I'm as we learn

44:28 and again, if you took the with dr Gifford, she probably walked

44:32 through a whole bunch of different mechanisms were very similar. So, here's

44:35 one. Here's another one. Here's one. You see it's the

44:39 What am I doing? Do I to have a receptor or am I

44:42 something without a receptor? All Ready for the weird or not?

44:48 weird one. The the one that like it'd be the easiest Vegas

44:52 Figo means eat so cell eating. this is different than end acidosis.

44:59 this is the key thing of why separated the two out with Figo

45:04 What you're gonna do is you're creating podia. Right? So, in

45:08 particular case, what we see is see the little bacterium see little red

45:11 with hairs on it. That's really . And what you're doing is you

45:14 a macrophage that macrophage says this thing doesn't belong here. And it actually

45:20 neutrophils, macrophages will actually follow the the chemical signal that it leaves and

45:26 it does is once it gets near doesn't wait for it to bind the

45:31 because that would be very, very to do. So what it does

45:34 it reaches out and extends its cytoplasm closes that side of plasma around it

45:40 creates a vesicles around the thing that trying to take in. That's what

45:44 can see here. Right? And we have our bacterium inside a vehicle

45:49 then we can take that vest off just do whatever we want to.

45:52 the case of a bacterium. Let's kill everything inside there just to be

45:56 , chop it up and just use the little tiny molecules that we get

46:00 our own use. And that's what is trying to show in this particular

46:05 , the type of vesicles that we're with. You can kind of see

46:09 that picture. See little green Those little green dots are lice ISMs

46:19 what do we have in license? does anyone remember from enzymes? That's

46:24 what I'm looking for. It's I didn't even ask what specific

46:27 There's a lot of different ones. . But the license um kind of

46:31 kind of like a stomach. Notice you kind of like like a stomach

46:35 a cell. All right, I'll point out this also requires a

46:39 cause there's all sorts of side of elements that you need to move and

46:43 and stuff. So again, vesicles and lots of a T.

46:49 This is just trying to show you formation of a life design, which

46:53 a form of the secular formation. here you can see there's the class

46:59 , what are we doing? We the material that we want inside that

47:03 that's already there. See it's being . And then what we do is

47:06 form the vesicles using the classroom. classroom is gonna recycle to allow me

47:10 keep making it more and more. then what I do is I take

47:15 and emerging and I'm forming this in zone. So in this particular,

47:20 , this is a pre licensed in zone. So what we're doing is

47:23 are creating a structure that will ultimately a license zone in this particular

47:29 So you're just adding more and more to it. But again, same

47:33 are involved, right, pinch off membrane using the class Teran transporting one

47:40 to another, merging it with another membrane like structure. Release the materials

47:46 it recycle. Do you think this energy? Yeah. All right.

47:56 , I'll be working right. so in terms of Exocet oh

48:02 what we're really what we're doing is uh I'm trying to remember here with

48:08 sausage toast is we're really kind of to it at this point. Not

48:12 release point. As in in terms the formation of the vesicles is what

48:17 trying to get at there. so it's not just limited to the

48:21 of the of the plaza memory. also there at the level of the

48:24 L So we're using it in both , is what I'm trying to get

48:29 . Anyone else. All right. we doing on time? What have

48:34 done? 11 48. Oh, only 15 minutes. Oh my

48:41 We'll see if we can get through rest of this stuff. Osmosis.

48:46 just make osmosis Simple. Everything your or your physical physics professor told you

48:50 wrong. Simple as most is a it's water moving down its concentration

48:57 That's all it is. Alright, you hear the word salute, just

49:01 salute. If you have a container has 100% of something in it,

49:05 more salute you add what happens to water? It gets less.

49:10 So, if you're moving to an of higher solute, that means you're

49:13 to an area of lower water. like to focus on the solid because

49:16 is the environment which the chemical reactions place. That's why they focus

49:20 But what we're wanting, what we're about when we're talking about osmosis is

49:24 the water moving to? So, just have to ask that question.

49:27 just moving to an area of lower concentration. All right. So,

49:34 a membrane is permeable to water and both substances will diffuse across the membrane

49:39 equip liberate, right? But if membrane is only permeable to water and

49:44 solid, then water is going to to quit, liberate itself across that

49:50 . Right? So, that means I have lots of salt over here

49:53 very little solid over there, water gonna move until it reaches equilibrium and

49:58 it can't reach equilibrium. Right? , that's kind of the idea with

50:03 is just think the direction in which is going. Alright, so water

50:08 from the area higher solute concentration. ? Um see Oh yeah, moves

50:14 Sorry, I thought from no, , no moves to Alright.

50:20 I have an example I use with but we'll get to it when it's

50:24 a couple of seconds here. The we use in biology when we're looking

50:29 the quantity of the of solute in body, we refer to osmolarity,

50:34 or osmolarity. Depending on what you're at, kilograms or mills.

50:40 And really what you're, what we're here is basically saying, we don't

50:44 what the solution is. Just how particles do we see and stuff.

50:48 . And generally speaking throughout the entire , your body has a roughly 290

50:54 Oz moles of solute throughout the entire . All right, so that's that's

50:59 point of equilibrium. And so just remind you when we're talking about

51:04 that means when you put something in can disassociate, for example, sodium

51:08 is you might have a mole of chloride when it dissociates, you have

51:12 mole of sodium, you have a of chlorine. So that means you

51:15 to um Oz moles of material. kind of makes sense. All

51:21 So, one of the things we to consider when we're looking at at

51:24 body is what are the number of ? Alright. So, what I

51:31 to look at in these next couple slides and I'm like, I'm afraid

51:35 going to spend too much time on . Is this idea of where does

51:39 move and how do and what are trying to maintain? So, remember

51:44 the first in that lecture on I said cells are compartments in which

51:48 reactions are going to take place and we're in home static balance.

51:52 When we have the right amount of so that the right chemical reactions can

51:56 . Do you remember we're talking about ? All right. So, what

52:00 if we put too much water into environment? We're gonna muck up the

52:04 between the water and the sites were with the osmolarity, which means we're

52:09 with the chemical composition, which means cells are no longer going to be

52:12 to function the way that they're designed function. So, your cells actually

52:16 mechanisms in place to help you deal that. And so this is an

52:21 of the sodium potassium pump. Doing . So, you can see

52:24 I'm pumping it in sodium Or I'm pumping sodium out of the

52:28 pumping potassium into the cell. The tiny arrows that you see in this

52:32 right here represent leak channels. What you think a leak channel does it

52:39 you things to leak. Yeah, so so when sodium is being pumped

52:44 eventually there'd be a point where there's more sodium, but because we have

52:47 channels, sodium sneaks back in and have leak channels for potassium. So

52:53 does potassium do, its like, , I'm gonna leak back out.

52:56 so we have to have the It's like a bilge pump saying,

52:59 , water is always getting in the , got to keep the pump going

53:01 I don't want the boat to And so you're always moving this stuff

53:04 that's part of the way that we that equilibrium. And so the equilibrium

53:08 not just in those ions between the the outside, but also with the

53:12 of water. If I kill the , those ions are gonna move back

53:17 forth. And then water is going go in to match up with the

53:22 that's kind of moving in because I , just by charge, what's happening

53:26 ? I'm gaining one charge for every I'm gaining three for every two that

53:31 lose. So there's a net gain a positive ion moving in,

53:35 You see that So water is gonna in the in the cell's gonna

53:39 What happens when things swell? Is a good thing? It burst?

53:43 can burst or it basically marks with chemical composition as well. So it's

53:50 to have these pumps and these league to ensure the balance. Now this

53:55 an example these two things. What if I put a cell into an

54:00 where the cell shrinks? All I'm just trying to make sure if

54:03 pictures look right to me see, yeah. So just look at the

54:08 here. So the outside of the is the same on the inside.

54:11 we're in equilibrium. But if I the osmolarity around the cell, water

54:16 gonna want to escape right? Because osmolarity is much lower. Remember the

54:20 the osmolarity, the more salute you . So if I have more

54:25 where does the water want to go to? The more solute? So

54:29 goes rushing out of the cell. causes the cell to shrink. But

54:33 the other way you look at, I have less water, I've concentrated

54:37 materials in the cell have created a different environment. Cell is going to

54:40 functioning. So what happens we'll all channels that we have are there to

54:46 balance the system. In other as water leaks out of the cell

54:51 channels are going to open in response allow different ions to move in to

54:58 the water back until we reach an in terms of the osmolarity. So

55:05 important here, malaria and equilibrium, amount of water in the cells.

55:10 converse is true is here what happens the cell swells again create, put

55:14 drop of cell into an environment which lower osmolarity. Water's gonna come rushing

55:17 the cell is expected to expand. means you now diluted all the the

55:22 machinery inside the cell, the cell function appropriately. So what do we

55:27 ? We have channels that allow you move salutes out. When you move

55:31 salutes out, the water follows cell back to its original shape even though

55:36 osmolarity is different, it's now able function because it matches the surrounding

55:43 That kind of makes sense. All , this is a weird one.

55:48 , Yuria is like you're a slow , you're right. The one you

55:52 jokes too and they kind of stare you for a little bit and then

55:55 it about a couple minutes later. you have a friend like that?

55:59 a little slow. Okay. Where you tell a joke and they

56:03 like everyone is laughing and they're just of like you can just see the

56:06 hamster wheel turning right? That's that's your area is. And so when

56:11 drop your area into an environment that's the osmolarity. Water is gonna naturally

56:16 towards it to reduce, you to bring equilibrium as far as osmolarity

56:20 concerned. but but Yuria can pass a membrane. It just does so

56:26 slowly. And so what ends up is that the curia will move to

56:30 other side of the membrane and at same time it draws the water with

56:33 . So you you initially see a of the cell and then you'll see

56:39 return back to the original shape. it kind of has this strange kind

56:44 behavior on how cells behave. Why do we talk about this

56:49 And who cares? Right, How guys work in the er I mean

56:54 know you got a couple of Right, so this is where we

56:57 asking questions even though I'm not a . Alright person comes into the er

57:01 dehydration. Do you give them pure ? Why? Because why? Because

57:12 cells will explode? Because what you is basically you're you're already dealing with

57:15 situation in which the environment right? low in water Or high end and

57:22 . So you put a whole bunch water out here. What's gonna

57:24 Right? It's just gonna start rushing and start cells causing them to

57:29 Right? So what do you give instead? Sailing? Isotonic solution?

57:35 . That's where that word isotonic. really refers to the osmolarity of the

57:40 . So hyper is a hypo those prefixes, you should already know hyper

57:44 high, same, high Polo. tonic parts are weird when that refers

57:49 the salute. So hyper high Same salute. Low salute. All

57:57 . And so the idea here is I am giving a solution, there

58:03 certain things I need to consider, what's it going to do the

58:06 Is it gonna cause damage to the ? Because when you have vast differences

58:12 water environments, water is going to to where there's less water and that

58:18 cause much harm. Alright, so just kind of showing here one of

58:23 things that are mostly the shift where water go? Well water mostly follows

58:28 . It will follow glucose as not so much by your area because

58:32 I said yuri a kind of moves it needs to go and there's an

58:37 , I'm gonna use a little bit . Um and I'm gonna I'm gonna

58:40 off on it now because I don't to confuse you all. I just

58:43 to just kind of run through these quickly and see if they make sense

58:47 you. Right, so if I an isotonic solution, here's the extra

58:51 , Green is intra so I add solution out here. Why does this

58:58 shrink? Why does it not move and forth? Why do you think

59:05 not a trick question? We already said it a couple of seconds

59:08 I so right, so it means the same salute, same water.

59:14 water has no desire to move in direction. It just stays where it

59:18 , right? And so it's gonna of stay there like that, you

59:22 a question or did you Okay? , see if you got the right

59:27 , give yourself a gold star. , what pure water? What's gonna

59:32 ? Alright, throwing pure water, the initial state, right,

59:35 I got a lot of water in . Osmolarity has now dropped. So

59:38 do you expect to happen? Where water gonna go? Look at

59:43 look at the similarities, it's gonna from left to right, It's gonna

59:47 from the extra cellular fluid in the fluid, right? It's gonna

59:52 And so while this initially swells eventually going over here to where there's less

60:00 ? That kinda makes sense, Because again, it's about osmolarity.

60:05 eventually you'll reach equilibrium. Look at osmolarity is now, okay, now

60:11 is over time, this is just imagine me taking a big old

60:14 needle because that's more fun and just right into your blood, that's your

60:21 cellular fluid. Got a lot of in your exercise, your fluid.

60:23 , where's it gonna go? You're just stay there, nope, it's

60:27 to go moving into the cells to equilibrium. Alright, what about

60:34 What is pure sodium chloride? Imagine a pure sodium chloride pellet into your

60:40 right, mm, get a good deer salt lick all right chop it

60:48 down, What's gonna happen? you don't increase the volume,

60:52 Because it's just pure solute. Look happened to the osmolarity now, out

60:57 control. Way over the above. what's gonna do? It's gonna draw

61:04 out and move to the environment until reach equilibrium. All I'm trying to

61:12 you to see here is the effect water and solute has on an

61:18 right? It will move itself, ? And it will try to reach

61:26 . Now, these substances, these are gonna move in one or two

61:33 across the cell or through a So, here what we're looking at

61:37 is we're looking at the digestive Alright, this is the interstitial

61:42 This is basically trying to show over this is the typical membrane. I

61:45 to look and see what we got . So, this would be your

61:47 tract. This over here would be space inside your body. Alright,

61:53 your digestive tract is exposed to the environment, y'all know that,

61:56 See, look, if I ah there's a big hole through my

62:00 , you can see one. I'm gonna show you the other.

62:05 So, if I'm moving materials from outside into a cell that's called

62:15 If I'm moving something from inside the out of the cell that's called

62:21 That's different than excretion secretion. Just in and out of the cell.

62:28 would be like, for example, urine and then getting rid of it

62:33 . That'd be excretion. Now the that things can be absorbed or

62:39 Or one of two ways I can through the cell or I can go

62:44 the cells up here. Up top , we can see the sodium.

62:49 absorbing the sodium here. I've got channel and then now I've got a

62:54 . Right? So, you can I've got this channel. I'm moving

62:57 this direction, but I want to the sodium levels low. So,

63:00 do I do is I use a and then I have another channel over

63:03 to allow potassium to be moving out then I'm pumping it back in.

63:08 , this type of movement from outside and back out would be trans cellular

63:16 . If I'm moving something in between cells like this is chlorine, This

63:23 is moving down its concentration gradient. is Paracel Euler transport. Alright,

63:32 drawing the chlorine from this direction? direction. What do you think?

63:36 a hard trick question, concentration. . The slope. Right. The

63:41 thing. It could be the concentration the the ion itself or it could

63:46 the electrical gradient as well. That's it in. Alright. In this

63:51 instance, it's probably just the But it might be both. It

63:56 be one or the other. All . So, whenever you're dealing with

64:03 cellular what you're usually doing is with downhill and then uphill or an uphill

64:09 then downhill. Okay. So notice translator transport, does it cost energy

64:16 moving uphill? The answer is Always gonna cost energy the whole

64:24 One step may not cost energy at , but the other one will and

64:28 comes first depends on which direction you're going. So, for example,

64:32 you have high acidity in your one of the things you have is

64:36 have cells in the kidney that move into those para tubular cells that

64:44 you know, your pump moving it , then you pump it out the

64:47 side. Right? And at the time you may have potassium being moved

64:53 the cell and then pumped out the side. So which step comes first

64:58 here's just examples of of these different of transports. So sodium we already

65:03 here's potassium. So potassium is going the pump and then now you can

65:08 it's being down its concentration gradient. type of transport is that? Co

65:15 ? Secondary active. Right. But of glucose inside the cell. So

65:21 uphill and then downhill. Yeah. important if it's taken Which 1?

65:35 , the sodium potassium pump? It's , one because we discovered it

65:40 That's that's one of the reasons. really it's because without it we couldn't

65:45 that potential energy that many of ourselves advantage of It was It's a it's

65:49 very primitive system, it's it's found every organism. So as one of

65:53 molecules that came to exist very early during evolution. And then so not

65:59 does it do that, but it you to create those unique environments internal

66:03 the cell. Yeah. It's it's is it literally is one of those

66:10 types of things where just cause. . I mean, I mean,

66:14 it could have been calcium and It just that wasn't the one,

66:18 just happened to be this one. know? Why was that selected at

66:21 very beginning? If I was around could tell you. But I don't

66:25 . But it's a fair question. sometimes we don't know the answer.

66:29 ? Or maybe someone does. It's not me. That's also feasible.

66:34 . I don't know everything I pretend do. But I don't promise,

66:40 again, chlorine, you can see case in case C. C.

66:44 doing that pumping chlorine in and then going down its concentration gradient.

66:53 Oh, like right here like so what's what's happening is is that

66:59 , you're gonna have leak channels and . So everything is being this is

67:02 problem with all these pictures. They show you all the mechanisms that are

67:06 . We're gonna talk about the eye I'm gonna actually show you this thing

67:09 the dark cycle. It's like the time I think in any picture that

67:12 show you that says, hey um see this channel here, this is

67:16 allows us to continue on forever. ? But you can imagine as the

67:20 goes in. Yeah, I can it out over there but eventually I

67:23 out of sodium over here eventually. what that means is there's got to

67:26 leaked channels on this side to allow to occur as well, right?

67:31 , in that case, you Yeah, there's gonna be like

67:36 I was I was getting a little in my head there for a

67:40 Alright, alright. How much time I got? Well, I'll answer

67:44 question. Huh. Too late. on the bottom. Uh And which

67:52 ? Uh Yeah, this one right . Yeah. So over here our

67:57 step would be using secondary active So it is a uphill first and

68:02 this is downhill. Yeah. And , right now today is not the

68:06 you're gonna go, oh I recognize of these in every one of

68:09 I mean, I've seen in C. C. Enough time outside

68:12 this class to know what it It's a co transporter. But the

68:15 time you see that you'll be I've got to really think about this

68:19 primary sodium potassium that we're concerned with of this pump system. So I

68:24 that sodium is the driver right, sodium is going down its concentration

68:31 Does that make sense? So that's driver of the other two. Where

68:35 potassium wanna go. Does potassium want go into cells? Yeah, because

68:40 know reasons, right? Actually, , it doesn't. It wants to

68:43 out right now, potassium wants to out of the cell so I'm pumping

68:48 against it's gradient. So, he to go in though. What about

68:51 , chlorine? A little ambivalent. truth is, is that it's it's

68:55 kind of sits at the at the of the cell and so it's just

68:59 of doing this to match the Right? All right. You said

69:05 got 10 minutes. This is man. I'm gonna just have to

69:13 talking fast. Alright with regard to to cell communication, we'll just get

69:17 far as we need to. I , eventually I do catch up because

69:19 of these lectures is is a lot . I don't know why. All

69:22 . But in essence, what we when we're talking about sales, what

69:25 talking about, How do cells talk each other? How do you guys

69:27 to each other? Right? You get on your phone and talk to

69:33 other. What's another way? Text you can do your Tiktok videos.

69:40 . That's a weird form of but it somehow works right. There

69:45 other ways that you can communicate. another way you can communicate away from

69:48 phone mail. Alright, meow, can yell across the room. You

69:55 pass a note, right? Ever notes in class or you guys too

70:00 to do that. You did do . Okay. Yeah. See my

70:02 . We don't have cell phones. we pass notes in class when you

70:06 caught. Oh man, brutal. . So, so in essence you

70:11 imagine cells that are near to each have different ways of talking to other

70:14 cells that are far away from each . And these are kind of different

70:17 . Now. The two primary forms communication are what we refer to as

70:21 and chemical 99% of the forms of in your body is chemical electrical.

70:27 like to sometimes confused with some forms chemical communication. Like when we think

70:32 a neuron we think oh that's electrical it's not really it's how I move

70:36 signal from one side of the cell another side of the cell. Just

70:38 happens that the cells are very, long. So for example, a

70:43 leaving my spinal cord going down to little pinky is as long as my

70:47 . So to get a signal from to the other side of that sells

70:50 electrical and then a chemical signal occurs go the next thing. So,

70:55 would be a form of chemical right? But so electrical is when

71:01 charges in the cell membrane are modified adjusted from cell to cell that are

71:06 each other chemicals. When the molecules gonna be secreted between two cells.

71:12 right. So, the mechanisms the one is just a Quran. You

71:17 see that gap junction from the previous is listed there. So, here

71:20 we have is we have two cells are connected to each other by a

71:23 of gap junctions. The molecules that this to happen are called connections.

71:26 form these channels that can open and between them. And this allows for

71:30 exchange of all sorts of different types chemicals including ions and when its ions

71:36 what we have is we create currents would be what type of electrical.

71:42 this is a type of electrical communication it can also be chemical because there

71:47 other types of molecules that can be . So, depending on the situation

71:52 either gonna be electrical or chemical. types of cells that are next to

71:56 other. One can have a One can have a ligand.

72:00 so, you see this often in immune system where two circulating cells come

72:05 contact with each other and their legends receptors come into contact. This is

72:09 is called as cell to cell And in doing so, what you're

72:14 is one cells telling the other cell to do right. You've heard of

72:18 helper cells you've heard of t uh of toxic cells. Why do you

72:23 I help ourselves called to help Because it helps. And what it

72:27 is it binds up to other like the TC cells inside the toxic

72:31 and tells it, you're the one needs to go and kill that thing

72:34 there. You kind of know how kill it. I'm letting you

72:37 That's okay now, that would be example of cell. A cell

72:43 Local signaling is of two different We have auto cringe. When you

72:48 the word auto Quran, what does mean? Auto means self.

72:51 I'm talking to myself, Have you talked to yourself? Yeah, when

72:55 studying, do you talk to yourself loud? Right. Have you ever

72:58 a note to yourself to do That's an example of the Quran signaling

73:03 now. You just sit there. would a cell have to do

73:05 Well, you got to think in of there's thousands of chemical reactions and

73:09 of processes are taking place. You be activating one system and that forces

73:15 to turn off another system and so releasing that whatever it is that you're

73:19 , acting back on the cell may you to turn off or slow down

73:22 whatever the process is that you're that would be an example of a

73:26 . All right. But you can here, what am I doing is

73:29 see, I'm secreting and I'm binding receptors on my own cell. That

73:34 be autocrat then we have Para it's very easy to confuse peregrine and

73:40 a Quran. But just a Quran literally next to like the cell that

73:44 associated with. Peregrine means the cells are around me nearby. All

73:49 So, if she was a cell chemicals, peregrine would be you and

73:55 and you and you and you and , but not the rest of

73:58 Because these are her nearby neighbors. , if you guys were holding hands

74:03 that was how you were talking to other, what would that be?

74:08 all right. You see the difference ? So it's it's releasing the material

74:12 becomes para Quran. All right. , the signaling molecules, in the

74:17 of this type of signaling whether it's of character are diffusing through the interstitial

74:22 to the nearby cells Okay, here attached then we have a long distance

74:31 here. What we're doing is releasing signal at some distance away from where

74:34 receptors located. You're more familiar with in terms of hormones. Right?

74:39 I have in my hypothalamus, the releases hormones that act on a structure

74:44 away the pituitary gland which is millimeters , which for molecules like forever.

74:49 then molecules from the pituitary gland will on molecules in or structures or receptors

74:55 are located my adrenal glands and my and so on and so forth.

74:58 is a long distance. That's a lot of distance. Right? And

75:02 what we have is the chemical is into the bloodstream so you can see

75:05 being released into the bloodstream and then travels throughout the body and then when

75:10 comes across the cell that has this receptor that it's going to cause a

75:14 in that cell. If the cell have the right receptor, no response

75:19 , Right. That's one of the things about signaling. You have to

75:22 the right receptor. Not every cell going to respond. Okay,

75:27 for example guys, we have estrogen our bodies. Talk to other

75:32 right? But we have very few receptors. So our body doesn't respond

75:37 same way to estrogen as say women . Which have estrogen receptors all over

75:42 place. All right. So, term for this type of chemical

75:47 we usually refer to it as a . Alright. But there's other terms

75:51 you might see come up every now then. They have varying sizes,

75:55 structure. And what they do is gonna bind to as we said,

75:59 receptor when I get to those last minutes, you've got to tell me

76:03 I'll just keep talking until those poor out. They're going to see if

76:06 gonna shut up. All right, like Yeah, that sounds good then

76:13 start talking about. Yeah. So there's lots of different types of

76:17 . And what I wanted to do I wanted to draw it out here

76:20 I just I'll just go through this in the next slide and then I

76:23 we'll just call it quits and then get to the actual receptors in the

76:26 lecture. Right. But we can here we have like ligand gated

76:30 Alright. So basically I have something can be bound and opens up and

76:34 ions to go through. All So what we're doing is we're changing

76:39 flow of ions which means we're creating current in the cell which can then

76:43 stuff. We have g protein coupled , basically what we have is we

76:47 a pathway a series of molecules that acting like a domino in other

76:52 a cascade of events that can turn multiple things. Alright. And typically

76:57 daming it for this intermediary called the protein. That's why they're called G

77:02 coupled receptors because the receptor is coupled the g protein catalytic receptors. These

77:07 some sort of enzymatic complex associated with . Whether they're part of the enzyme

77:12 or the enzyme is attached to it matter. That's that's whatever the case

77:17 be. Uh that means they can relate things or they can take off

77:22 and when you phosphors later takeoff phosphoric on a molecule. What you're doing

77:26 you're changing its level of activity. right. Um inter cellular receptors you

77:32 cells that can have receptors inside the in different ways. Typically these can

77:36 the nuclear receptors which can be found us all in the nucleus and act

77:41 transcription factors to change gene expression. then we have these weird ones that

77:46 never heard of before reading this text , which is strange I mean but

77:50 you can take a receptor that actually destroyed or damaged through some sort of

77:56 icis and then those fragments actually become which is kind of interesting. So

78:03 all sorts of weird stuff out The general rule of signaling is uh

78:10 off the receptor needs to be able recognize what's binding to it. That

78:14 pretty logical. Right? Right. you match what you're attracted to once

78:18 get bound that's gonna cause a change the shape of the receptor that then

78:22 in some sort of internalization of the . So what we say is the

78:27 signal turns into the inside signal. what trans deduction is. It's changing

78:31 from one form to the other. , so it's transducer from extra to

78:37 then you're gonna get transmission. So that means is is that that internal

78:43 now is going to work its way a pathway to either amplify itself or

78:48 specifically localize and activate the right defectors simply is the thing that causes the

78:58 . Yeah, I know. And you can modulate it. How much

79:03 are you going to change the activity the effect? Er What what mechanisms

79:06 there in place to do that? is the ultimate change in response?

79:11 turned on this thing ergo the cell does something different, I turned off

79:14 thing ergo the cell does something different lastly I'm a dad. So this

79:19 the way I'm gonna explain when you in the room and turn off the

79:21 . You better dang well turn off light when you walk out of the

79:24 and that's the same thing. Anything turn on, you better turn

79:27 that's what termination is. Otherwise the keeps doing stuff it shouldn't do alright

79:32 we come back we'll finish up this here I forgot from the orientation week

79:38 what it

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