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BIOL 2301 Human Anatomy & Physiology I - 2103_lecture06_0203
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00:02 I think this is where we left . Was this right? Just look
00:06 , okay. Where I pause thought myself, this would be a good
00:10 to stop. Um What we're going do today. But you know,
00:14 we sit here and freeze in this big space um is we're going to
00:20 the question, how do cells talk each other? All right. And
00:23 ultimately we're going to ask how our connected to each other. And the
00:27 here is to really kind of lead the last little thing before the
00:32 which is what our tissues. So, you guys know when the
00:37 is that's kind of the important Right? When when is our test
00:41 thursday? A week from today. , if you haven't signed up,
00:43 need to go on the course Sign up for it. I'm sure
00:46 all the great slots are still No. Alright, okay. I'm
00:53 trying to make sure we got things here. All right. And so
00:58 kind of leaving we're starting off where left off. And there's some stuff
01:03 actually, there's a couple of slides kind of like, we're just they're
01:06 just for examples. All right. so, what we're trying to look
01:09 here is we're talking about how do move things across the membrane? And
01:12 said there are channels and they are . And so channels, they create
01:16 water filled passages which you can see , you can see there there's that
01:23 passage. So things are able to across talked about carriers carriers being molecules
01:29 you buy into. That causes the of the shape of the molecule so
01:32 it closes on the side that it's the receiving side closes and then opens
01:36 on the sending side so the molecules move through. And typically when we're
01:40 about these things, we're saying this a result of moving from an area
01:44 high concentration to an area of low . All right. And so what
01:49 can do is we can use these to regulate how things move from one
01:54 or the other. You just need have some sort of signal that tells
01:59 cell what to do. Alright. what we have when we talk about
02:03 channels for example, you're gonna hear term gated. Alright, now,
02:07 is is just a term whoever came with that, they could have said
02:11 , they could have used any sort term that refers to something that opens
02:15 closes. All right. And so when you hear gated channel, you
02:19 this is a channel that exists at time in a period of time when
02:23 either open and when it opens things can pass through or it closes
02:26 things can't pass through. And then is the thing that causes? It
02:30 usually associated with that gate gate. you can see up here, we've
02:34 voltage gate ligand, gate mechanical, gate thermal gate. And really all
02:40 is saying is the mode. that's what it's referring to, the
02:45 . The mode to cause this thing open the key is this thing.
02:51 when you're looking at a voltage gated , what you're looking at is you're
02:54 at the ions that have stacked up either side of that membrane and now
02:58 have a charge difference and that charge detected by that protein because it has
03:04 and negative charges on it. And the charge difference becomes a certain
03:09 that's going to cause a change in shape of the protein which causes the
03:12 to open, which allows things to through, thus changing the difference.
03:17 , so you can think about like I got a lot of positives on
03:20 side, when that opens, those ions are going to pass through and
03:23 it becomes more positive on the which will lead it to closing up
03:27 . And that would be what you're as your key. That's kind of
03:33 it's a difficult one to think the easy one to think of is
03:36 ligand gate because this is kind of we do when we deal with our
03:39 gates, right with our own We have a key, we go
03:43 the door, we stick our key , we turn the key the door
03:47 and then we pass through. All . And so that's what a ligand
03:51 channel is. It's basically a ligand just a fancy word for saying a
03:56 molecule that acts like a key. a molecule that binds another molecule.
04:01 so the ligand gated, we have molecule that binds to its binding site
04:04 causes the gate to open so things pass through. Then the ligand is
04:09 . The gate closes. That's kind the easy one. But you can
04:13 you have other types of things that responsive to changes in the shape of
04:17 cell. Have you ever been German pinched? Does it feel
04:23 No, it hurts. Right. body says ow in response to a
04:27 . Well, the reason you you got pinches because the cell that
04:31 touched or twisted opened up channels that ions to go in that created a
04:36 that went up to your brain and , this doesn't feel good and it's
04:39 for yourself. That's why you say Alright, that would be Mykonos sensitive
04:45 or some sort of defamation that's taking thermally gated. If you ever touched
04:50 hot stove or I don't know if ever done the dry ice challenge.
04:55 do dry ice challenges. They're bad you, right. You know,
04:58 hot or cold to an extreme is to cause damage. And so those
05:01 in temperatures are detected in the same . It's just you have thermo gated
05:06 they change in response to the change a change in temperature. All
05:11 so that's what a gated channel is what the modalities that causes them to
05:17 . Now we have this term we , okay, well we have uh
05:21 we need to move things against their . We want to move things from
05:25 area of low concentration in the area high concentration. And in order to
05:28 that, we need to apply Alright, and energy comes in one
05:32 two forms. It's either applied directly to applied indirectly when it's applied directly
05:39 the form of ATP binding to the and releasing that energy. So the
05:45 could do stuff that would be primary transport. All right now, the
05:50 one, we always uses the sodium 80 pes pump. Alright, but
05:54 gonna show you another one. That's common one. That's really simple.
05:57 the pump should be the key word . It's like I have water here
06:01 I want to move it there. wants to stay here. But what
06:03 I have to do is to use pump to move it out.
06:06 that's what the pump part is. in this particular case, what we're
06:10 is we're taking energy in the form a T. P. When the
06:13 is there. Now, the system allowed to move forward. There's some
06:18 sites on the inside of a on the inside of the of the
06:22 on the side that faces the cytoplasm favors the binding of sodium, sodium
06:28 naturally bind there and if you get sodium to bind and http is
06:35 that's going to allow for a I'll change it change in the shape
06:38 the molecule so that flips out and the other direction. So now you
06:42 see it's open on this side when flips like this, it is no
06:47 having an affinity towards binding sodium. other words, it says sodium,
06:50 don't like you anymore and it kicks out. sodium has no choice but
06:53 leave and in place what happens is two binding sites for potassium appear.
07:01 , so now there's an affinity for to bind. Now potassium doesn't want
07:05 go into the cell anymore than sodium to go out of the cell,
07:08 already high sodium outside the cell, already high potassium inside the cell.
07:12 because of the way this energy works because of the binding affinities, sodium
07:18 going to bind there, it has choice, it's just bumping around and
07:22 , oh this looks like a comfortable to hang out and it just kind
07:25 sits there and waits, right? then when the when you get three
07:29 them it's like, okay, now all leaving, you don't have a
07:32 . So it leaves it gets released there's no place to bind. So
07:35 just wanders out. This is the diffusion thing that we're talking about.
07:40 then now you have these affinities for , potassium doesn't want to go in
07:45 cell, but it's like, oh , there's some places to kind of
07:47 out, so I'm gonna go sit and sits down its binding site.
07:50 you get to potassium is there, changes shape back to the original shape
07:54 now those binding sites disappear and potassium on the inside. And then now
08:00 energy that you use to cause this allows for a TP to bind up
08:04 and then you just repeat the cycle and over again. So at the
08:08 of 1 80 P, I moved sodium is outside of the cell.
08:11 moved to potassium into the cell and creating more and more and more of
08:16 disequilibrium in terms of potential energy. other words, if I got lots
08:21 sodium on the outside of cell, do you want to go in
08:26 Right, So I have potential It's like those ping pong balls I
08:31 getting shoved into a closet, The ping pong balls want to be
08:35 out across the floor. One ping thick, ping pong ball thick.
08:39 , Would you agree with that? all you got to do is open
08:42 door and ping pong balls are going come. So energy is stored when
08:47 create disequilibrium, right? And that's this system does is it's storing up
08:53 by first at the cost of Right? So, basically, it's
08:58 a battery. It's not a but it's like a battery. I
09:01 energy here. All I gotta do connect the ends and then I can
09:05 current. I don't have a I have energy stored up. I
09:09 have to find a way to create current. Alright, now, here's
09:14 example of this type of activity. a little bit simpler. I probably
09:18 have led with this one. go ahead. Is there two different
09:22 for the potassium? Yeah. the question is there are two different
09:26 for the potassium. The sodium. answer is yes, sort of.
09:30 right. Do not write this So, it'll just make things more
09:34 . The place where the sodium So, I've got to do
09:37 All right. There's a place where sodium bind. When they change
09:42 What they do is they form the where the two potassium bind potassium can't
09:48 or sodium binds, sodium can't bind potassium binds. So, yes,
09:51 are different spots, but they're exactly the same location. Right. It's
09:56 the change in the shape of the creates a different binding site. That's
10:02 of cool. All right. Which why it's capable of doing what it
10:06 . Right. Alright. So, the easy one. This is a
10:09 pump. Alright. And what it . It takes a proton, you
10:12 protons represented as a hydrogen plus, all that is you lost your
10:17 So, now all you have is nucleus. And that's one proton.
10:20 . And basically it says, look the cost of a teepee. I'll
10:24 protons from this side of the membrane that side of the membrane.
10:27 now, Alright, big deal, cares? We'll license owners use
10:31 This is how you get the inside license. Um all acidic because it
10:35 these proton pumps pumping protons into the . Um Now, you've created a
10:40 environment that can do stuff. very low ph another place this is
10:44 , really important is in the making a teepee. You have proton
10:49 We're not gonna go about how But what they do is they push
10:54 into a special compartment and now you potential energy And you have another channel
11:00 allows the protons to come through. every time a proton comes through,
11:03 allows you to crank some cellular machinery allow you to make a teepee.
11:10 , it's a way to to store energy, Right? Using pumps to
11:16 up energy. All right, that's just an example. So,
11:22 want to show you now why we up energy. An example of why
11:25 would store up energy. That's the active transport. Yeah, no,
11:33 first example use shoulder different sport. , no. Mhm. Three
11:42 Mm hmm. Well, so, right. So, the question is
11:50 So here we've got 1 80 It allows me to move three sodium
11:53 potassium. And over here is well, what's going on here?
11:55 , it's the same sort of It's one proton per 80 P.
12:00 , So, so, again, each system is going to be
12:04 All right. And so they try we try to cartoon these things out
12:08 we dramas like they're supposed to represent actually going on. So, this
12:11 the 1 to 1 ratio of protons a T. P. The expenses
12:15 the cost is 1 80 P. think of it as a coin?
12:18 putting in the machine, cranking it that moves the proton. All
12:23 So, here we've done we've now moved a whole bunch of sodium.
12:27 that was in the first example with potassium https pump. So, we
12:31 lots of sodium outside the cell. of potassium inside the cell. And
12:35 we're gonna do now is we're gonna that lots of sodium to help us
12:39 things in the same direction as the . So, he wants to go
12:43 the cell. But we got things we want to move in the
12:45 But we don't want to expend energy . An example of this would be
12:49 , glucose is a sugar which represents , right? Do you want to
12:54 energy to move energy? No, a that's a bad idea. That's
12:59 wasteful. So, what we've done we've stored up energy in the form
13:03 the sodium, sodium wants to go the cell, glucose for example,
13:08 to go into a cell but there's of glucose in the cell. So
13:10 moving against it's gradient. Right? instead of expending energy to move
13:15 why don't we just go ahead and the gradient that we already had that
13:18 created with sodium sodium wants to go . So, you can think about
13:22 like this Alright. With secondary active . This is what we refer to
13:26 either coupled or co transport. Things moving in the same direction.
13:31 So here what we're looking at is got sodium that wants to come into
13:35 cell down its grading. I want to come into the cell. But
13:38 going against it's gradient. And so have a molecule that's capable of binding
13:42 sodium and glucose on the outside of cell, sodium binds, it creates
13:47 binding site for glucose with glucose binds then the molecule changes shape and moves
13:52 of those molecules on the inside. has gone where it's wanted to
13:56 glucose has gone into where it wants go. Alright. Everything's moved forward
14:00 it wanted to go where you wanted put it And it's all because we
14:05 potential energy or stored energy by moving through primary active transport. Now,
14:12 is just one example. We have , many mechanisms that use this type
14:16 co transport. Alright. And it's advantage of the physics, right?
14:21 sodium, low sodium things want to in that direction. Alright,
14:26 I want to move it over here I'm just gonna move them together.
14:29 the energy that sodium has stored up move something against its grading.
14:35 if you can't fathom this, I a really, really bad example.
14:38 want a really bad example? this is no longer hitting it.
14:42 to hit a lot, but you are a little different generation than when
14:46 grew up and when I went to . All right, So, I
14:47 to college in New Orleans. Alright to Tulane University and no matter where
14:52 went, every bar had a ladies some night. Okay, what is
14:57 ladies night? Ladies night women drink or can have no cover to get
15:01 . Right, depending on the All right, So, what would
15:05 all the guys would know where the nights are and there'd be some sort
15:09 cover charge and we wanted to go . Right? But man, if
15:14 brought in a woman, you if a girl went in with
15:18 I wouldn't have to pay the She gets in for free. So
15:20 you do is you see all the hanging outside the bars with girls coming
15:24 in groups, like they normally do it's not like you're trying to separate
15:28 the herd this time now. It's like look I want to go
15:30 Um But I don't want to pay if you bring me in I'll buy
15:34 a free drink. And so that's we got in. Right? Do
15:38 see the symbiosis here? How how works? One gets in free,
15:43 know? But she don't want to for drinks because you know why spend
15:47 when someone else buy you drinks. ? But I want to get in
15:51 I don't want to pay the cover to get in. So we both
15:54 what we want right? I don't to spend money. I don't have
15:57 spend money and don't have to talk you after this. I just want
16:00 go in at the same time and making a deal to make that
16:04 So some of you are looking at going, that's a stupid example.
16:06 of you're going I like this. right. That's kind of what secondary
16:12 transports. Like two things moving together though they can't do it by
16:21 This slide in this slide or for not to memorize at all.
16:26 What these are are basically showing you the different types and these are the
16:32 this is not even a complete list just showing you that if you understand
16:36 concepts of what a channel is and a carrier is, what co transport
16:41 that there are different systems That the has created that used the same sort
16:46 mechanisms. So you learn them once know the idea of the concept and
16:50 you'll see them repeat themselves. So , for example, the sodium potassium
16:53 pes pump over on this slide. think maybe it is on this
16:57 Oh yeah, here's one. This a plasma pump that's changing calcium and
17:02 protons. It's called a calcium uh . And you can see it's also
17:07 we can sequester wait calcium into some our organelles uses the exact same mechanism
17:12 described primary active transport, expensive 1 P. I can move to things
17:17 opposite directions. All right here we a co transport there is that sodium
17:22 it says salute. So in other , what it's saying is,
17:24 we're going to use sodium a lot move things against its own gradients.
17:28 glucose is an example. The amino that you consume are examples of
17:33 We've got a whole bunch of different of channels that are voltage gated.
17:37 here we can see an exchanger. again, the exchanger here is going
17:40 take advantage of these concentration gradients. going to exchange one for another.
17:47 again, you don't have to memorize of them. Just showing you
17:50 And so they have all different Look here, it's that proton
17:54 they're all over the place. And , if you learn them once you've
17:58 them all well, you've learned about they work. Okay. So why
18:05 we care? Right? Is it because I mean and I want to
18:09 you learn horrible tiny things that you'll see in your entire life? All
18:13 . The answer is of course, , that's that's my goal. I
18:16 up in the morning and said, do I screw these people's lives?
18:19 the answer is no, Oh I've got one other. I've got
18:22 Asus and then psychosis. The reason this is because the way that cells
18:27 to each other, they use these and these carriers and receptors to allow
18:32 to communicate. Now this is another of transport here. It's called vesicular
18:38 . We're gonna be looking at two of psychosis and endo psychosis. So
18:42 out window is in And what we're is we're using those vesicles.
18:46 so, you can see here, my vesicles, here's my chemical that
18:49 releasing and we've already described how it a snare merges with the plasma membrane
18:55 up and now you've released that material into the environment. This material is
19:01 someplace. All right. We just addressed where it's going yet now in
19:06 to move a vestibule. We've already about you're gonna have those dining those
19:11 , Those little motor proteins. it's going to require energy to move
19:14 and to dock them and do all stuff. So vesicles, they're
19:18 They require energy, but they allow to secrete large particles out into the
19:22 cellular fluid through the process of Exxon . Xo outside. Oh,
19:31 I don't know what that means. psychosis is when you're taking things in
19:38 the cell using vesicles. Now, I was in your seats, we
19:43 two types, we had just receptor a toxic toast and we have to
19:48 psychosis and we left it kind of that. All right. But there's
19:52 quite a bit of it at this . All right, So Figo psychosis
19:57 , again, same thing. You're need energy, you're gonna be taking
20:00 large part portions of the membrane, you're gonna be doing different things.
20:04 Fico psychosis is literally means self And so, you can imagine here
20:10 a macrophage or another uh immune cell is responsible for removing cellular debris or
20:17 , like a bacterium. And what you're gonna do here with Figo
20:21 is the cell actually creates the suda . They kind of reach out and
20:26 they surround the thing that they're consuming I'm gonna put consuming in quotes,
20:31 know, because it's not. And you've done is now you've encased whatever
20:35 is that you want to consume inside vesicles and now you destroy, you
20:39 , bring that to a license destroy what's in there. So,
20:42 here it's kind of a reaching out grab this is different than the other
20:48 . All right, pinot psychosis. kind of named to kind of be
20:53 of Figo psychosis here. I'm eating now I'm going to be drinking something
20:58 this is really an indiscriminate form of cellular absorption. So you can imagine
21:03 my plasma membrane. What I do I inv agin eight. So in
21:07 words, I pinch off of vesicles reaching out. It's just basically it
21:12 downward and whatever happens to be in extra cellular fluid right there and I
21:17 that's what I've captured. So there's specific I'm going after Vegas psychosis.
21:22 looking for that bacterium. I'm looking that material. So I'm I'm specifically
21:28 something to get in pinot psychosis. doesn't matter. It's just whatever is
21:32 . I capture it and then I'm to process what's ever in it.
21:37 if I want to be more I'm gonna use another type of endo
21:41 which is called receptor mediated endo psychosis hear what you have is you have
21:48 in the membrane. Alright and Remember we said ligand is just something
21:53 binds to another molecule. Liggins buying receptors and the receptors congregate and localized
22:01 an area that has other molecules that them. And what happens is you
22:06 this in vaginal nation this pit that and then it pinches off, you
22:11 , as you build downward. And now you've captured something specific. So
22:15 in pinot psychosis you're not capturing anything . It's just random stuff that you're
22:20 , receptor mediated into psychosis is I am specifically looking for this using
22:26 receptors to bind and bring into the what I'm looking for. All
22:33 So, these are the three broad . And if you continue in the
22:38 of biology, you'll learn that there's to this that these are broken down
22:42 further. But for our purposes this all we need to know. So
22:46 closest to creating endo psychosis is taking using vesicles and there's three different ways
22:52 I can do when it comes to it texas one where it's out reaching
22:56 where I'm just pulling in one that's one that's non specific. So it
23:04 into. Okay, we said, do we have and why do we
23:07 about this stuff? Because cells have talk to each other. Right,
23:10 need to communicate in order for you to work. They have to be
23:14 to talk. So, what we here is a field that's called cell
23:19 . This idea that cells are using and electrical signals to talk to one
23:26 . Now, when we say this type of communication is electrical or
23:30 . A lot of your books are to refer to like for example,
23:33 way that neurons send signals across their as electrical signaling. Its not its
23:38 signaling? That that distance across the is electrical, but that's not the
23:42 part? The signaling is at the 90%. If not more of the
23:48 that cells talk to each other is chemical messages. Which is why it's
23:52 understand channels and and carriers and exocet because what you're doing is you're releasing
24:00 or allowing chemicals to move into cells do the work of talking to each
24:07 . All right now, there's a of different things that are going to
24:10 how cells talk to each other. . How close are they to each
24:14 ? What sort of speed do you in order for them to talk to
24:18 other? What is your intended And so these names that we're gonna
24:23 looking at? Help us to define type of signaling that's taking place.
24:28 right. So, you use the to help you understand what's going
24:32 So, one this is the easiest of signaling. And you're gonna sit
24:36 and probably go, well, why I want to talk to myself if
24:38 a cell? Right. It's called . And that's when you send a
24:42 out and it binds to a receptor the surface of the cell that sent
24:46 and then communicates back to the cell do something? Alright. And that's
24:51 of It makes sense. Right. like why would I talk to
24:53 Have you ever talked to yourself? . Have you ever written yourself a
24:57 to do something to remember to do or to force you to do
25:02 Yeah, that's kind of what an signal is. It's basically saying there
25:06 a pathway that needs to be Maybe it might serve as a negative
25:11 to tell you to stop doing So, if I'm making a whole
25:14 of this signal, whatever it maybe binding that receptor may tell me
25:18 stop making this stuff in other to serve as a way to balance
25:23 how much I'm going to make. would be just an example. So
25:26 is like the easiest form. The has to have a receptor that binds
25:30 the to whatever the chemical is. ? And then you're just talking to
25:36 , that's autocrat that's the easiest form communication. The most common type is
25:43 . Alright. Peregrine means nearby right? So if she is a
25:48 and secreted signal, then it's going affect the cells nearest her.
25:54 So it'll expect expect probably they sell most then this one a little bit
25:58 and then this one a little bit , but she's way too far away
26:01 another organ. So it's not gonna her at all. Alright.
26:05 peregrine signaling is the surrounding cells All . And what you're doing is you're
26:10 that chemical to those surrounding cells? if your cell has the right receptor
26:16 you're going to respond to that If you don't have the receptor,
26:20 not going to respond. Alright, this is one of the key things
26:26 about signaling is you need to have right receptor in order to respond to
26:30 chemical now because these chemicals or signals going to be limited not only in
26:39 of quantity, but in terms of far they can travel. There are
26:43 out there sitting there destroying the signal fast as they are being released.
26:47 right. There are specialized. So a neuron. Alright. We're gonna
26:51 all about neurons. Alright, neurons a specialized form of peregrine signaling
26:57 You can see the cell has these arms. It's called an axon.
27:00 what happens is is that long arm the very end is releases where you're
27:04 to see where you're releasing the You have receptors on the receiving cell
27:09 are just underneath that region and that's a synapse. And so what you're
27:14 is you're sending that signal to a specific location but it's still peregrine because
27:19 am I doing? I'm sending it a nearby cell. Okay. But
27:23 going to dive into the details of a little bit later, Jax to
27:31 you see that prefix just a means to which sounds a lot like near
27:36 , doesn't it? Right. So , if she's the cell is the
27:41 near or next. Well, see us would be next. Right.
27:47 in terms of biology, when you her next to juxtapose refers to an
27:53 connection between them. Alright, there has to be some sort of
27:58 that's taking place, not just merely like okay, we're bumping elbows.
28:03 . It means literally there is a contact between the receptor and the ligand
28:11 the two cells are connected to each . And so materials pass in between
28:17 . All right. And that's what two examples here here's the direct
28:20 This one is using what are called junctions. All right. On this
28:24 , what we have is we have as part of the membrane. It's
28:29 other words, it's jutting from the . It's a trans membrane protein.
28:33 . Right. And then over here this side we have receptors. And
28:39 these two cells can either be fixed a tissue or what we are most
28:45 with. As in the immune we have cells like T cells that
28:50 receptors and another cell can come along bind to it by that cell.
28:55 now they're talking to each other. right. So that's the direct
29:01 Now these molecules where they're talking to other are abbreviated cams as a class
29:08 molecule and its cell adhesion molecule, easy way to remember this is like
29:13 velcro one side is a hook, other side is an eye and they
29:18 to each other and they bind they'd and that's how you get that.
29:23 right. So, that'd be like direct contract direct contact. Hear what
29:29 gap junctions are. And we're gonna in a little bit more detail a
29:32 bit later because we said how cells connected to each other here with a
29:36 junction. What you've done is you've a passageway or a tunnel between two
29:41 . It's basically you're forming channels that close while they do close. But
29:45 now materials can pass directly in between cells if they're small enough to pass
29:50 these gap junctions. So, if have lots of sodium in this cell
29:54 sodium is going to move down its gradient into the other self. And
29:58 it serves as a way to create between cells. Yeah, it doesn't
30:03 energy. Not always. There will cases where it does, but for
30:07 purposes right now. No. So, think about it like
30:11 Alright. If two cells are connected each other and ions are moving in
30:17 cell, what do we call the of ions, anyone know? And
30:25 close. I don't know why it . That randomly decided current. It's
30:36 current. So, remember how I , where was it? There are
30:42 types of signaling. The things that looked at so far have been chemical
30:51 . Alright. That's even chemical chemical here with gap junctions is electrical
30:59 Right. This is how your heart , right? Basically, a cell
31:05 up a channel allows the flow of . The cells are all connected to
31:08 other. So this cell affects this which affects this cell which affects this
31:11 . So and so and so Basically, ions are moving down their
31:16 radio. That's just an example. don't need to know how the heart
31:20 today. Right. But they're connected each other. Alright. So,
31:24 where current is taking place. Next is long distance signaling. We refer
31:32 this very often as endocrine signaling. signaling is basically how your brain communicates
31:39 chemicals to other parts of your Alright, This is how hormones
31:44 Alright. Hence the term endocrine. , here you can imagine what I
31:47 is a cell that's producing this chemical we call a chemical message that's released
31:51 one of these cells out into the . A hormone so that hormone travels
31:56 the blood. So, you can it's released from my brain traveled all
31:59 my body. Goes to a very location in my body that has the
32:03 receptors. It's going to travel but it will bind to the cell
32:07 has the right receptors. And that can be at a far distant place
32:11 I'll just use an easy one for . All right, above my kidney
32:15 above your kidneys, we have a tiny gland called the adrenal gland.
32:19 right. And so you have chemicals are released from the blood brain,
32:24 the pituitary gland that will travel through blood and go to that adrenal gland
32:29 tell you to release certain hormones to and regulate other parts of your
32:35 Alright, an example of that would cortisol is released from the adrenal
32:39 Alright. Cortisol is used as a that regulates your responsiveness to stress And
32:46 is not. Oh, I have test tomorrow stresses like it's always 20°
32:50 zero. Alright, So, your knows how to respond in an environment
32:55 you're always under stress. All So, this would be that kind
32:58 example. And again, they're showing blood vessel here is kind of the
33:02 . But you can imagine I've got travel through thousands and thousands of miles
33:04 blood blood vessels to get where I to go. I need to have
33:08 cell that has the right receptor and I have the right receptor, I
33:12 that and tell that cell what to . So, that's another form of
33:18 his endocrine signal. Now, when get to one of these cells that
33:22 a receptor, there's one or two of signaling that takes place all right
33:28 the surface of the cell, there's that's going to take place inside the
33:31 . Alright, when you see this metadata, tropic trophic refers to the
33:37 . Alright. It causes an effect what it's saying. So it's like
33:41 do I cause effect? Well, when I looked at the first
33:44 I'm creating a metabolic activity, metabolic , metabolic action. And so what
33:51 has and says, look, here's receptor, here's my leg and my
33:54 binds to a receptor. And then causes a change in the shape of
33:59 receptor, which affects a whole bunch molecules inside the cell. It creates
34:04 is called a transducer action cascade. , all I'm saying here when you
34:09 the word transaction, it's what it to trans means to shift or to
34:15 . So it turns an outside signal an inside signal. That's really what
34:20 is. Okay. And it's basically on one molecule which turns on another
34:24 which turns on another molecule. These are growing up. Ever play the
34:28 mouse trap. Forever stacked dominoes and them over. You. Ever do
34:32 dominoes thing? That's easy one, ? Put a whole bunch of dominoes
34:35 really press one domino. They all over. That's kind of what a
34:39 cascade is, it means there's just whole bunch of molecules in a row
34:42 are each affecting each other and ultimately the end of the transaction cascade,
34:47 going to get some sort of Now, in physiology would go in
34:53 lot more detail about this, if ever wondering, why do I have
34:56 many different molecules in a transaction And I'll show you an example here
35:00 the next slide. It's because you're just affecting one response, you can
35:06 multiple responses and you can also amplify . And so that's why there's multiple
35:12 . Usually it's not just because the doesn't know what it's doing and it
35:16 did stuff. It's at each You can see amplification or you can
35:20 this one is not only affecting this is also affecting that pathway, so
35:25 and so forth. So what is cellular response? Well, you're either
35:31 or activating biomolecules. So what you're is you're changing what the cell is
35:38 . All right, You can turn cell on to do something or you
35:41 tell the cell to stop doing The other thing that you can do
35:44 you can do this at the level the gene. Alright, so very
35:48 at the end of these pathways you're something that goes into the nucleus that
35:53 you which genes to turn on or tell you which genes to turn
35:57 So, meta papa tropic pathways act a ligand binding to a receptor,
36:04 a cascade to create the response. . So the key thing there is
36:11 you have that transaction cascade. This an example of transaction cascade again using
36:18 rather than really scary names of See I bound to the receptor,
36:24 receptor activates a molecule that wasn't This one activates another one, which
36:29 another one so on and so on you get the response. All
36:34 And what this is showing you is simply how each step along the way
36:39 in the activation of something else. what we're not seeing is that maybe
36:44 will not only activates this, but might activate another protein or maybe in
36:48 another protein Or one of these activates of these. One of these activates
36:53 of these. And so, what done now, you've gone from 1
36:56 10 and from 10 to 10,000. is why small signals become massive
37:06 Have a question. Yeah. How it know when to stop? That's
37:10 really good question. And I'm glad thinking about that. Not important for
37:13 today. So, the question is does it know when to stop?
37:17 , for everything that gets turned on a cell has to be turned
37:21 All right. In other words, mechanism that you see here, there's
37:25 reverse mechanism that is that is going opposite direction. Now, here's an
37:30 of that. She predicted. All , So, again, the protein
37:37 doesn't matter. It's the process that . Okay. And so what we're
37:42 is here, we have a A molecule in the transaction cascade.
37:48 . This happens to be a G , the G protein existed in the
37:52 form or the active form. And you can imagine, like up here
37:56 this is the G protein, here's thing that activates it. Right.
38:01 so what this is saying is I have a mechanism to activate
38:06 right? So there you go. easy. And now this thing can
38:10 , the G protein can do what designed to do. But what we
38:13 have is we have something that is for returning it back to its original
38:19 . Alright. And this is what the system to be activated and reactivated
38:24 and over and over again. You're not dependent. It's not you're
38:28 pressing a button. The system is just on and there's nothing you can
38:30 to stop it. So, every a ligand binds a receptor, something
38:36 along and removes the ligand from the . Every time you activate a molecule
38:40 the pathway there's another molecule that's there inactivate the pathway, the timing of
38:46 is dependent upon what's there to do work. So, that's the important
38:52 . All right, for us. , what we call these are what
38:54 refer to our molecular switches. Something that turns it on something that
39:00 it off the second type of receptor you're going to find in the surface
39:09 to do with those channels that we . Alright, so, notice the
39:14 basically turned on a cascade. It's moving a molecule from one side of
39:19 of the reception of the membrane to other, it's using the receptor to
39:25 the signal from one side or the . Hence the term transaction. But
39:30 we're gonna be moving things into the . Usually it's going to be the
39:33 of ions. Sometimes it could be and this is where you're gonna use
39:38 a tropic. And so again, is some sort of effect. What
39:42 we doing while we're creating an ionic ? We're moving ions. Alright,
39:48 , if I have lots of sodium the outside of the cell, if
39:52 move it onto the inside cell, going to change the nature of the
39:56 of the cell. I'm moving lots positive charges on the outside, moving
39:59 inside. That's going to make the more positive than it was previously.
40:04 right, so, how do I that? Well, all you gotta
40:07 is open up more channels, Nazi a tropic effect. Alright,
40:12 here, same sort of thing is got a ligand right now. This
40:16 not the only mechanism we describe. are some of the other modalities we
40:20 described, we said ligand, but another one? You guys remember
40:25 No. Remember we had a list four. The four common ones.
40:29 voltage was one of them. That's hard. Once it was voltage Ligon
40:33 then there's two others to remember thermal and then Mykonos sensitive.
40:38 so here we're just using ligand as example of ion attractor because like I
40:43 , it's the easiest one to right? And here you can see
40:46 is that chemical, the chemical message one cell to another binds to the
40:52 that opens up the channel that allows to pass through and then the ligand
40:58 be removed. That's going to close channel. So these types of signals
41:01 very, very short lived signals basically cause the channel open and caused the
41:05 think about like this this door right and you can see it has an
41:08 hinge at the top, It's being open I think by you know this
41:13 one of those kind of locked in . But you can see that this
41:16 door is one of those doors fly and let it go. What's it
41:19 do? It's gonna close again, . And that's kind of what these
41:22 these channels are because they exist in state or closed state for a very
41:27 short time. The open state for very short time. And they were
41:29 back to the closed state. They're opening in response to whatever the signal
41:33 . So that's why you get this response. This is how neurons work
41:39 the most part, the last type signal that you should be aware
41:46 Is that not every hormone not every molecule is going to be water
41:51 It is going to necessarily bind to receptor located on the surface of the
41:57 . Some of them are lipid All right. Those hormones that we
42:02 at called steroids are lipids right? we said their lipids so that means
42:06 don't want to be in water. don't want to be out in the
42:10 outside the cell. They want to inside the cell and find themselves into
42:14 as fast as they can or at find something that keeps them away from
42:17 water. And so the way they is when they are released out of
42:23 blood they're like desperate to get And so what they do is they
42:25 their way into cells and they'll be to their receptors which are found inside
42:32 cell. Now this type of receptors a nuclear receptor and it's called a
42:36 receptor because it works in the Now when it's not bound it can
42:41 either in the nucleus argument inside applies could be anywhere inside the cell but
42:46 the hormone comes? Yeah I don't why it does that. I don't
42:54 . All right. When the nuclear gets bound by the hormone by the
43:06 , what's it doing? Alright. it will do is that creates a
43:10 that causes it to move into the and now it's capable of binding
43:14 N. A. What these types receptors serve as our signals to cause
43:20 to be turned on or turned They're not working through traffic signaling
43:25 They're not activating or inactivating things that already inside the cell. Like the
43:30 pathways are all right so the transaction all the protein is already there in
43:36 . All you gotta do is turn on and you're you're activating the cascade
43:40 . What I'm doing is I'm going to turn on new genes or turn
43:44 genes that are active and that's how change the activity of the cell.
43:49 right now this takes a long So as an analogy I want you
43:54 think about the lights in the room ? How do I turn the lights
43:58 the room on and off. There's switch and it's right over there if
44:02 ever come in the room is pitch you go and press the button.
44:05 will come on. So that would an example of a transaction cascade.
44:10 to make the lights turn on are there. All I gotta do is
44:14 the receptor which is the light Alright for this An analogy would be
44:19 order for me to turn on the in the room. I have to
44:23 all the wiring. I've got to all the lights in place and I
44:27 to put them in their sockets and I have to flip the switch or
44:30 at least allow energy to get to . Which do you think takes longer
44:34 get the lights on in the The 2nd 1. Right. And
44:38 this is why this takes a long . But because you're activating all of
44:43 processes and making all these proteins, going to be made for a longer
44:47 of time and then something being turned and turned off because it has a
44:51 regulator. Right? In other I am making a whole bunch of
44:55 in order to make this cell And so it's going to stick around
44:58 longer period of time. And so to give you a sense of of
45:03 . Alright, When I'm working through transaction cascade, right? If I
45:07 , you know, add a hormone that and turn it on. The
45:11 will be within seconds to minutes and everything will be turned off again maybe
45:17 the top end an hour. When I do the same thing through
45:23 nuclear receptor pathway, I applied the to the cell, I won't see
45:28 response for maybe, you know, minutes to an hour. But then
45:34 response will stick around for a couple days. Alright, so that's the
45:40 . Alright, one spot response is . One sponsor is response is
45:45 The quick response. Only six rounds a short period of time. The
45:49 response sticks around for a long period time. And that's what this one
45:52 doing. All right. So, bring all this stuff up why we've
46:01 about all these types of signaling and will become more apparent when we start
46:05 about the individual cells and the individual . Especially because the two primary systems
46:11 we're gonna be discussing, are we to be the nervous system and muscular
46:14 . Right. And we'll be able see how muscles and neurons and
46:19 Talk to each other through these types peregrine actions. Alright. And then
46:24 you move on in A and Two and you start talking about how
46:26 digestive system works and how the nervous is responsible, regulating reproduction stuff.
46:31 know, you'll see in metabolism in , you'll see how these hormones
46:37 But understanding that all cells do these of things gives you at least that
46:42 step into understanding because even your skin this and that's the first thing we
46:48 about is the integral mint is your kind of Cool. Alright. So
46:55 help us understand tissues, right? know that cells talk to each other
47:00 we also know that they're connected to another. And now we're about to
47:06 landing the plane as far as cells concerned. And many of you are
47:10 you finally And then we just have tissue lecture and then we start really
47:14 some real anatomy. Sounds good. . All right. So cells are
47:20 to each other and we call these membrane junctions. There's different types.
47:24 have different functions. Junctions and functions broke into the conjunction junction song.
47:33 right. You guys are too All right. When I was really
47:38 , you can go if you have plus you can go watch all these
47:41 schoolhouse rock. You know you know I'm talking about? three people conjunction
47:45 . What's your function? Alright, , that's how we learned. This
47:49 how we we learned stuff. Before went to school we watched saturday morning
47:54 . All right. So, these junctions. They have many different functions
47:59 I don't have a song that goes it. All right. So,
48:04 are classes. All right. the first type of class of junction
48:07 called the Dismas. Um Alright. Desmond's Ohm is one that holds cells
48:12 are next to one another adjacent They hold them in close opposition to
48:17 other. So, you can see . We've got a couple of things
48:20 . You can focus on the on text or you can focus on the
48:22 . I think the picture is easier understand. So, basically a series
48:26 proteins that creates a plaque or basically barrier a a hardened structure. All
48:32 . And then on the other side that plaque you have a series of
48:36 molecules that stick out so that they attach to the opposite cell which will
48:42 the exact same thing. All So basically you have a plaque and
48:45 have a bunch of cams and those are interacting with each other and now
48:49 have these two cells connected. But ensure that cells when they move,
48:54 tear each other apart. You also a series of keratin molecules,
48:58 These are those intermediate filaments. And these intermediate filaments do is it takes
49:04 forces that are being distributed between the cells and then distributed among or around
49:10 whole length of the cell. so, in essence, what you
49:14 is you have two cells that are to each other and the tension or
49:18 forces that hold them together are being , that there's less tension at the
49:22 of the Desmond zone. So what does, it provides mechanical, still
49:27 . We've already mentioned this briefly when talked about indian Burns. Right.
49:31 reason when someone gives you an indian , and if you don't know
49:35 an indian burn is when you grab by the arms, usually a younger
49:40 , right? And you take their and you twist one way or the
49:44 . The skin doesn't come flying off the forces of pushing are pulling two
49:50 apart from each other. Um they're to be dispersed, not only across
49:55 entire length of each individual cell, then to the next cell, through
49:59 Desmond zone, to the next cell and so on. So then it
50:03 hurts. It doesn't actually damage the . All right Now, Desmond zone
50:10 2/2. So one cell contributes one the other cell contributes the other
50:17 Alright. Desmond Zone. So helps distribute force, creates mechanical stability between
50:24 cells. All right then we have is a picture. This is a
50:29 picture. But it kind of shows because cells aren't separated by that much
50:33 . Alright, So, but this of shows just like you can see
50:37 would be the Desmond's own Desmond These are those points are where the
50:40 zones are. And it's trying to you the intermediate filaments. The artist
50:43 a terrible job because all those intermediate will be connecting to each other.
50:47 , you can imagine if I pulled this would be pulling on all these
50:51 things and that forces being dispersed among whole. A group of cells,
51:01 means half. All right. hemi Desmond's owns half of Desmond
51:07 Alright. And here, the difference with the hemi Desmond zone to Desmond
51:11 is you're still dealing with that Remember? The cell has its half
51:15 . It's contribution. So, it its cams. It has that
51:19 It has its intermediate filaments, but no cell that is connected to
51:23 it's connected to the connective tissue of basement membrane. Alright. So,
51:28 proteins that are found within the basement . And this is what it's trying
51:32 show you. And here you can these cams. And these cams are
51:36 to those structures which now holds the in place. Alright. So the
51:42 tissue is what you're now attached Its not sell attached to sell it
51:46 attached to connective tissue. That would the hemi Desmond zone when I was
51:55 your seat. These didn't exist. if they did. They never taught
51:58 about them. Alright. Adherence junctions similar to Desmond's OEMs. The difference
52:05 is the type of fibers that they . Alright. So again, I
52:09 really have a huge plaque but you have cams. But instead of having
52:15 filaments, what you have is you these micro filaments, the active
52:18 So they're a little bit stiffer. flexible than your than the intermediate
52:23 But it says in the name, does its job? What is the
52:27 ? It adheres. Right. So cells to adhere to one another.
52:31 . It's just a different type. , you can kind of see here
52:35 our technology gets better. We can discern more clearly what molecules are involved
52:41 different types of things today. that's that's that's the key thing for
52:50 . All right. So, what has is the acting molecules.
52:54 these are micro filaments. And then you look at sorry, hear what
52:58 said is that these are the intermediate . So, it's keratin. But
53:02 filament. Right? So, if went back and looked at those pictures
53:06 we talked about the different types of in the cell. It's the red
53:11 versus the yellow fibers. Okay. the pictures, Alright, tight
53:21 um they're also called including junctions. reason is what they are is they're
53:27 the connections in a ziploc bag. guys know ziploc bags. Right.
53:32 . So, if you were to the zipper of a ziploc bag,
53:35 create an environment inside the bag and create an environment outside the bag and
53:40 can break through that barrier. if you buy an inferior one from
53:45 he may be but But in essence you do is you have a series
53:49 of of strep or strips that basically and that's kind of what the tight
53:55 is. Instead, it's not You a series of proteins. These proteins
53:59 called inclusions. And what they do they basically locked. So, you
54:02 one on one side of the on the other cell. You have
54:05 one. And those two interact. that creates this barrier. All
54:08 You can see that they're trying to you a whole bunch of them.
54:11 , that's why there's this huge And so this actually creates this kind
54:17 unique structure so that you have an on one side of the cell versus
54:22 area on the other side. I think this picture a little bit
54:25 to kind of demonstrate this. So we're looking at here, this is
54:28 typical and epithelium All right. And can see over here this they're trying
54:33 say this is your small intestine, is on the other side of the
54:37 epithelium, or sorry, the epithelium . And so what you have you
54:41 molecules those molecules want to get into bloodstream but they can't pass in between
54:46 cells because those tight junctions prevent materials actually passing through. It's like the
54:53 bag. We have an environment down and we have a unique environment up
54:57 created by this little barrier. if you have a molecule molecule to
55:02 to this side or from to get here to there from here to
55:06 it either has to pass through the , which is what this is trying
55:09 show you. Which means that the has to have some sort of carrier
55:14 to grab it and move it into cell. And then you have to
55:16 a carrier on the other side to it and release it from the
55:21 That kind of makes sense. In words think about a building that you
55:23 to go through, right any building got sec or S. R.
55:29 over here, right? Many of walk through it to get to the
55:32 side of campus, right? So order to get through it, you
55:35 to have a door on this You have to have a door on
55:37 other side. Right. And that's of what this is like. It's
55:41 you have to have some sort of to get through that sell on either
55:44 . Want to go through it. right. Or I don't have a
55:49 junction. But if you're trying to unique environments, you want to seal
55:56 The areas in between those two. , what this does is not only
56:01 a unique environment out here. This be called the typical side. It's
56:05 unique environment. This would be called basal lateral side, which has its
56:10 unique environment. Those two areas are different from each other. But if
56:13 go inside the cell, those proteins make up the tight junction also serve
56:19 kind of a barrier inside the Alright, there's proteins that are connected
56:24 arranged around these tight junctions. that means the stuff over here inside
56:29 cell is unique versus the stuff that's here inside the cell is unique.
56:34 , tight junction. Not only create unique environment around the cell, but
56:38 also creates a unique environment inside the . So let's say I'm a cell
56:43 secretes things. All right. Which do I want to secrete?
56:47 I want to secrete towards the a side. So, knowing which side
56:51 a pickle on which side is basil kind of important. I don't want
56:55 create enzymes that break down proteins into body. That equals bad. That'd
57:02 digesting myself. So, that's why become very important, creates not only
57:09 environments. So the thai judge creates environments outside the cell. Alright.
57:14 defining what is a typical versus but does the same thing on the
57:18 of the cell, directional movement of through the cell. I have an
57:26 . This is the only creates unique . Not the only type, but
57:30 definitely one of the major types. right. But the idea here is
57:39 understanding directional arrangement. Okay, that's the key thing for us. All
57:45 now, here's the gap junction you can kind of see what have
57:48 done? I've created a channel. channel can exist in open and closed
57:52 . The molecules that we're using here called connections. See I told you
57:57 biologists are simple. We don't name weird stuff. If you see the
58:01 connection, what do you what do think it means connect? Yes,
58:16 . No. So, remember. , with regard to a gated
58:19 a channel is going to be It's more molecular. This would be
58:23 molecular would be smaller. So, can imagine on this cell right
58:27 what I have is a series of that are associated with side of the
58:33 . Right? So, if I to move something from here to
58:35 I have to have a proper carrier a proper channel. So let's say
58:39 have a you eat something with lots salt because channels are easy to understand
58:43 you're thinking salt. Right? you got a lot of sodium,
58:45 got a lot of chlorine. I want to disperse that sodium and
58:48 through my body. So, what I gonna have to do? I'm
58:51 have to move it from here down here. So, if I have
58:53 sodium channel there, it allows me move sodium into the cell and then
58:57 might have a pump to pump the back out of the cell. That
59:02 of makes sense. So, we see it in the picture because it's
59:07 that's not what the picture was designed . But to it would be too
59:10 to see in the picture. All . I'm trying to see if we
59:13 go back maybe a little bit All right, that's a good question
59:19 it's very easy to not understand And when you're using cartoons all the
59:23 now, you have to just kind pretend like you understand what it looks
59:28 . All right. So, here , what are the what are the
59:32 junctions for allows for two cells to connected so that the environment here so
59:37 can add this is inside one cell uh in contact with the other environment
59:43 that other cell. So, it for the passage of materials back and
59:48 based on concentration gradients. So things going to move down their concentration
59:55 All right now I've asked on Tuesday many guys watch that video? Some
60:03 you guys and you guys did more you guys watch the video after last
60:06 . Yeah. Kind of maybe. . Did you notice how when you
60:10 started that video that it showed you mesh work this mess of stuff on
60:15 outside of the cell? Well, they're showing you is this right
60:19 this extra cellular matrix. And so mentioned we had the black oak
60:23 the glycol Calix just refers to all sugars that are attached to the things
60:27 on the surface of the cell. the extra cellular matrix is literally a
60:32 of proteins and other things that are affiliated or associated with the cells on
60:37 outside instance. Name. Extra Outside the cell matrix, lots of
60:42 . Alright, so here we're going see a whole bunch of proteins,
60:47 of collagen, a whole bunch of different types of fibers, fiber next
60:51 laminate. Um these things are going be secreted by cells and what they
60:56 is they serve as both anchors or with their environment. Alright, so
61:01 the integrations and stuff that are connected them. So you can imagine if
61:04 integrated into is interacting with that that right there. It creates that
61:10 that direct contact. Something about that direct contact right there. That
61:19 that then serves as a signal to the cell what to do. All
61:25 . So, the extra cellular matrix is important because the interaction with it
61:31 that cell tells the cell how to or how to respond. All
61:37 Everyone here has gotten cut at least in your life. Right.
61:42 What you've done there? If you when you've got a cut, did
61:46 have separated out the epithelium of the mint epithelium has a unique feature called
61:55 inhibition. What contact inhibition is It says when I'm touching another
62:01 In other words, when I'm in this sort of matrix and I'm recognizing
62:06 interaction of my surrounding environment, I'm gonna grow. I'm not gonna
62:11 I'm not gonna multiply but when I'm contact inhibited, right? In other
62:16 , if I'm not touching something, I'm gonna grow and divide.
62:19 think about what happens when you get cut, right, you get a
62:23 , you bleed. And then if pay close enough attention over a couple
62:26 days, you'll notice that the cells of grow back kind of grow back
62:32 where you had the cut and then left with in theory a perfect pop
62:40 post sound, you're going to end with a perfect uh repair of that
62:48 . Now, the more damage you , the less perfect it becomes.
62:51 if you had a scar in your too. Can't tell who's still
62:57 Ah Someplace, Someplace in there. . Okay. Yeah, I fell
63:02 I fell off a cliff when I about 18 years old. 20 ft
63:05 plant is beautiful. I broke my . Put a big hole in my
63:09 as well. Because divers divers do have any divers in here? I
63:14 , it was beautiful except there wasn't . All right. It's a great
63:23 . All right. But anyway, , that's that would be an example
63:26 imperfect because it was a big gaping in my chin. All right.
63:32 that contact contact inhibition is because we these extra cellular matrices that the cells
63:38 to figure out how to interact with environment. It would be an example
63:42 that. So, signaling with the . Uh huh. Yeah, we're
63:51 down to the last booth and then died. Let's see if I actually
63:55 batteries. I should. Good news we're down to the last little bit
64:03 , so. Mhm. Mhm. right. So, the last little
64:34 here has to do with how cells . Remember we said all living things
64:40 reproduce. Now, here's the good is not a biology class. You're
64:43 gonna have to know every little You're not gonna have to be able
64:45 identify the different stages of the cell , but we need to understand cells
64:51 a lifecycle. They go through this of replication. They go through a
64:57 of growth. They go through periods no growth. They may actually grow
65:03 multiply and make a whole bunch of and they stop growing and they just
65:05 of hang out and that's all they . And that's what the cell cycle
65:09 describes here. Alright. It's the that occur within a cell to allow
65:14 cell to reproduce. Alright, It's into two primary periods, which is
65:19 this picture represents. We have the which is the madam anabolic phase of
65:24 , periods of growth and activity. in other words, this is the
65:28 of time when cells are doing what designed to do. Right? So
65:33 what all this stuff, all the here. Well, Dark Blue.
65:37 Help me out with this one. color is that? Purple?
65:42 Alright then, this wouldn't be violent . Pink. We're going to go
65:48 . Okay, Alright, so the up here represents the interphase is the
65:52 of time when a cell divides is to as mitosis. Alright, that's
65:58 myopic phase. So that's what this is here. Now, all these
66:03 are going to go into a little more detail than we need to
66:06 but I want to just kind of the picture for you. Alright,
66:10 interface, we have sub phases. right, so, we have these
66:13 these G phases. When you see G one G two over here,
66:17 zero. These are phases in which cell is doing its activity. The
66:21 phase is sometimes referred to as the phases. So they're they're basically moving
66:27 doing their stuff. So you can cells like your skin, you have
66:31 that are undergoing cell division actually creating and more skin cells. It also
66:37 that skin cells must be dying all time. Alright. But your neurons
66:41 early on during your development, you you go through multiple growth and division
66:47 but then eventually they stop and then just hang around until you die.
66:52 that would be the G0 basically where stop dividing and they just kind of
66:56 their stuff. But if you have that are actively producing daughter cells,
67:01 going to go through some growth They're going to copy their DNA.
67:04 would be the S phase the replication s stands for synthesis, that's where
67:09 came from. And you kind of kind of go through from growth to
67:13 to growth too. All right. , within these to ensure that the
67:20 has met certain standards in order for to divide. In other words,
67:24 want to make sure if I'm replicating D N A I am I have
67:29 right number of copies and I've I've all the right stuff. There's going
67:34 be these periods of going through and sure all that stuff takes place.
67:38 we have some specific stop signals built which is what those lines represent to
67:43 that you're ready to go to the phase. I don't know a good
67:47 . You think of it like at end of the term where you have
67:49 take your final exams. Right? you ready to go on to the
67:53 class? Right. That's what those really there for. All right.
67:57 you do all the things you were to do? All right. So
68:00 G to make sure that the cell ready to divide the G. One
68:04 says, are you ready to go and start synthesizing? Are you supposed
68:08 go off and stop synthesizing? Are done? So that's what interface
68:13 It's the period of metabolic activity. if you're still in the process
68:18 making your D. N. A your D. N. A.
68:21 that you're able to move on. a question. So from G 1
68:26 G zero. Yes. So basically think of G0 is is I've met
68:32 the conditions I need to in order do my functions. So instead of
68:35 and dividing and making more of I'm gonna go this direction now I'm
68:39 doing what I what I was supposed order was designed to do. So
68:44 would be what the G. Zero it's moving outside that this cycle kind
68:49 an arrest phase. All right now . You've all learned this at some
68:55 point. You learn pro fes metaphysical hero phase. Anyone here ever learned
68:59 the sub phases of pro phase. a couple a couple of people.
69:04 those are all fun. It's like goody I get to learn these and
69:07 you find out no there's even Yeah we don't have to worry about
69:12 . All right and I'm not gonna here and throw a picture up here
69:15 say tell me which one this is . And the truth is is that
69:21 definitions that you see over here really kind of um if you if you
69:26 at them it's kind of like okay kind of nebulous because what you're trying
69:31 do is you have to understand it's like I am in pro phase now
69:36 in metaphor. You don't do that ? It's there's this kind of fluid
69:41 through all the phases. And so characteristics helped identify what's unique about those
69:48 but you could be kind of in two and just say well that's anna
69:52 . Someone may come along and say no that's meta phase and that's perfectly
69:56 . So in histology you got to all this stuff but for our purposes
70:00 understand that. The first thing I've do after I've replicated my D.
70:04 . A. Is I now have separate the D. N.
70:06 So that I can then separate the . And so these four stages are
70:10 death defined steps that allow me to all that stuff. So basically have
70:14 break down the nucleus. I line all the chromosomes in the middle of
70:17 cell and then I tear those paired apart the the copied apart. So
70:23 that they're on opposite sides of And then once I do that then
70:26 can divide the cell to and then once I divide the selling to now
70:30 have two clones of the original Alright, I have two daughters.
70:36 that's what all of these represent. term side of kinesis. You can
70:40 here, psychokinesis really begins around there then it continues on. And that's
70:44 you can see here is the side kinesis showing in the tele phase or
70:50 . All right. And so what psychokinesis is is simply the division of
70:54 cytoplasm. So, really mitosis is the division of the nuclear material.
71:01 right. By definition, that's what refers to psychokinesis refers to the division
71:07 the cytoplasm during this larger process of division. All right. So it
71:15 here and the way you can think how this forms is if you were
71:18 take a little rope and encircle the . I don't know what's going on
71:27 . Someone's pointing lasers at me or . I don't know. All
71:31 So you can imagine if I take little rope and throw it around the
71:35 and then begin to draw that lasso the rope tighter and tighter and
71:40 That's what's going on. So you're squeezing off the two sides and that's
71:44 you separate out the two cells. . Do we need to know just
71:54 we don't need to know what is . That's that's what I'm gonna ask
71:58 . If I ask you anything about ? The cells have to divide that
72:02 , divide their nuclear material. That be mitosis. And they also have
72:05 divide there's cida plaza on the side kinesis. I put this up here
72:10 that you understand that there are stages I could be rude and I could
72:14 you the stages of pro phase as , but I don't want to do
72:17 . That's just mean. Yes, . Is it just one Really?
72:26 , again, it's like all of things knowing when something begins or so
72:31 really the idea is that you're gonna these cleavage furrows form. So if
72:34 can imagine around sell like so and seen the nuclear materials separate, you
72:39 see a slight formation of the cleavage . Now, if you have the
72:45 stain, you could probably stain for and you probably see, okay,
72:49 is the accumulation of the acting at site where I'd expect cleavage furrow to
72:54 . So, you could probably call at the beginning of psychokinesis as
72:58 So, again, it's kind of a it's a judgment call, you
73:01 ? So part of the problem, just gonna I'll say one of the
73:05 we have in terms of teaching you is we speak in absolutes Alright.
73:10 like this is meta phase, you ? That's that's not how this is
73:14 to work. Meta phase is more a broader definition. So that when
73:17 looking at a cell and you see right up there going, oh,
73:21 kind of aligned, Alright, I'm meta phase, you know? But
73:25 it was like slightly unaligned, would say no, that's not meta
73:28 It's still in pro phase. It's meta phase. You mean? That's
73:32 the judgment. Okay, All I think that was the last
73:35 wasn't it? Did I finish Are we out early today? Like
73:40 minutes. Alright, I like Okay, guys, stay warm,
73:45 gonna get cold over the next couple days, like, like massachusetts
73:52 Mm hmm. I'm I bet you're you weren't there for those 30" of
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