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BIOL 2301 Human Anatomy & Physiology I - BIOL2301 lecture05_0130
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00:02 Um what we're going to do today it's actually kind of busy making sure
00:07 have three different areas that we're going cover. We're going to look at
00:10 we make proteins. All right. we're gonna look at the process of
00:13 and translation and then we're going to of take the stuff that we learned
00:19 Thursday today's Tuesday. Right. Thursday. And we're gonna kind of
00:23 it together, kind of give a sense of what's going on in the
00:26 in terms of how we're taking these that we're making and where they're gonna
00:31 . So we're just gonna kind of some things together and then we're going
00:33 switch gears and kind of with some stuff that deals with physiology.
00:38 we're looking at the process of diffusion and really how molecules move back and
00:44 across the membrane. And I'm just to promise you now, like,
00:47 I said, I'm not going to like everything we do is going to
00:50 fun and exciting. A lot of stuff going across the membrane will feel
00:54 . Um Truthfully, it just is of boring but it's probably some of
00:59 most important stuff you'll learn with regards understanding how cells work. All
01:03 So we have to cover it. right. So um we're gonna kind
01:07 run through stuff. Uh I will out things like this is not so
01:12 to learn the details in this particular type thing, right? So uh
01:16 we see stuff with lots of information I say it's not that important,
01:20 say, understand this simple concept, really kind of the idea. All
01:25 . And so our starting point here with the central dogma of genetics,
01:29 central dogma of genetics basically says, , we have DNA that's found inside
01:33 that DNA contains all the instructions. taking that DNA and using it everywhere
01:38 not the best strategy in the world you would destroy the the actual hard
01:43 , the original copy. So what do is we make transcripts of our
01:47 RNA. So we convert the message we want and we pull it out
01:52 the DNA and we make these transcripts RNA and that RNA is then going
01:56 be translated because within the context of sequence of the RNA is a code
02:02 defines which amino acids go in which . So we get RNA is translated
02:08 become proteins. And this is what process is here and what we're going
02:11 be looking at a little bit more . And it's that proteins that do
02:16 work of the cell. All So the central dogma is DNA to
02:20 A to proteins, proteins do the . So with that in mind,
02:25 got a lot of words on this and some of these words are going
02:27 go with things that we're going to looking at in the next slide.
02:30 right. So what we have here this slide is we say,
02:34 the DNA contains all the genes and of these genes in your body,
02:39 there are 33,000 of them. It's sequence of those nucleotides. And within
02:44 sequence, there are parts that we and there are parts that we don't
02:49 , the parts that we use are exxons. The parts that we don't
02:53 are called introns. And so if were to take that whole gene and
02:58 that whole gene as a message, would be stuff in there that would
03:02 nonsensical and would mess up the So when we make RNA, which
03:08 a copy of the gene, we're to have to modify that copy of
03:13 gene to remove the stuff that we need. All right. So exxons
03:18 the parts that we need. Introns the parts that we don't need.
03:22 so we're going to remove the they're what we refer to as coding
03:26 non coding sequences. Now, when comes to RN A, there are
03:30 , many, many different types of in the body, the longer we
03:34 and the more we look, the we discover just as an example,
03:38 was reading just for fun, not scientific article, but I was just
03:42 the news and they're like new life discovered. I was like,
03:47 No, you know, and it's called an obelisk. It's not actually
03:51 living thing. All right. It's small strands of RN A that actually
03:56 proteins on themselves. I mean, , from that their sequence,
04:00 But it is a biological molecule and gets all excited when you discover something
04:04 . All right. But the idea , is RN A, we keep
04:08 more and more things with RN It's crazy, but for our
04:12 we only care about three of the . All right. The first is
04:16 a transfer RNA A transfer RN A that when I showed you the picture
04:21 that three dimensional RN A that was transfer RN A. It's the one
04:24 looks like A T. It's kind easy to remember because it looks like
04:27 T and the job of a transfer A is to bind up to a
04:32 amino acid. And part of the RN A has a sequence that recognizes
04:38 coom that's found as part of the that you're reading. So it plays
04:43 role in bringing the amino acid you for translating RN A into a
04:51 The other type is a messenger RN . That's the thing that you're
04:56 So it's MRN A. And so is the thing that is a copy
04:59 the gene. And then the third you need is you need to make
05:03 ribosome to read the MRN A. so to make a ribosome, you
05:08 RRN A. So that's ribosome RN . So you can see in the
05:12 of making proteins, we have DNA we have at least three types of
05:17 A. Now seeing a picture like is not particularly helpful. All
05:22 or a list like this is not helpful. We're gonna go and we're
05:26 see all these things in place. I just want to kind of define
05:30 , this, these nucleotides for you not, these nuclei, these nucleic
05:34 for you. So that when we talking about them, you're like,
05:37 , I don't really know, I go back and I can look at
05:39 definition. This is what the slide , is a list of definitions.
05:43 , before we get into that, need you to understand when we talk
05:47 DNA in the nucleus, that's not that's found inside the nucleus. In
05:51 , the DNA, when we talk the chromatin, the stuff that contains
05:56 your DNA, it's not just it actually consists of three parts,
06:02 has DNA in it, it has proteins in it. It has some
06:05 A in it. All right. , this chromatin is the way that
06:09 package or is the way that that we manage our, our
06:14 All right. Now, if you've done any sort of biology, you've
06:18 seen the picture of chromosomes and They always draw like this.
06:22 It's like these little X looking structures it's like, oh, look,
06:26 . Yeah, that's only occurring in . For the most part, your
06:31 probably looks like your sock drawer if me. Right. It's just stuff
06:36 . All right. And while we at that and say, my
06:39 that is totally unorganized. How does body ever find anything in that?
06:44 not cells? We don't know how organize themselves quite well. All
06:48 But yeah, that's, that's considered and part of that organization is because
06:53 the structures that are involved in uh chromatin. So while we think of
07:00 DNA or the chromatin as being the , that only makes up about
07:04 And then we have these proteins, things called histones and what you're seeing
07:08 , these are the histones, they there and they help organize and arrange
07:12 DNA and allow it to become compact compressed when you are not using it
07:18 it unwinds itself from the uh the so that you can then use
07:23 All right. And so we have , the tight wound ones and we
07:27 the unwound ones. And so the wound ones are referred to as
07:32 this is resting or silent DNA stuff not using and then the unwound is
07:39 the euchromatin. And when you look a cell and you look in a
07:43 , you're gonna see areas that are in areas that are light, the
07:46 that are dark are gonna be the that have hematin and the areas that
07:49 light are gonna be the areas where is. And this is showing you
07:53 the activity of the nucleus is actually place. And then the RN A
07:58 part part of that RN A is stuff that you're actually creating or,
08:02 transcribing and creating messages from. All . So we take this unbundle
08:10 this what's seemingly disorganized stuff and when time to actually go through the process
08:15 replication, we're going to reorganize it these structures that we're more familiar
08:21 which are called chromosomes. So, is the collective DNA plus the stuff
08:27 organizing it. A chromosome is when compact it all up just prior to
08:33 uh uh replication. All right. with that in mind, DNA is
08:40 complex than we give it credit for . We're going to use and unwind
08:47 so that we can then read it make RN A from it and from
08:50 A, we're going to make And so this picture here is trying
08:55 make a really simple model of what gene looks like. So you can
08:59 this represents all of the DNA in body or in your cell. All
09:05 , it represents the chromatin. And the context of all the chromatin,
09:09 going to be a region that represents single message for a single protein.
09:15 I'm saying that knowing full well that message can be multiple proteins. All
09:19 . So a gene is simply a , it is the code or the
09:25 uh the well the nucleic acid message ultimately going to become the protein
09:31 On average, if you take a at all 33,000 genes in your
09:35 if you look at it, there about 3000 base pairs or 3000 nucleotides
09:39 length, they contain within them, exxons and the introns which can actually
09:45 that, that, that length of whole thing and it actually increase
09:48 And if you look down below, is kind of what we kind of
09:53 it as when we are drawing it because we, we have to create
09:56 models for ourselves. And so what say is like, hey, there's
09:59 beginning and there's an end to a , right? Just like there's a
10:03 and end to a song, a and an end to a poem,
10:05 beginning and an end to a right? Everything maybe I should do
10:10 you're more familiar. A beginning and end to a tiktok video. How's
10:15 ? We're good with that one. , all right. So I got
10:17 couple of smiles out here in the . All right. So what we
10:21 is when we draw these things we say, hey, here's our
10:25 , the gene contains within it, that we're gonna use. We have
10:29 that we're not gonna use. It a starting point and it has an
10:32 point. We have a name for starting point. We call it a
10:35 . We have an ending point, call that the termination or terminator
10:40 Then there's some other stuff where different can bind up and regulate. So
10:43 regulating regions as well. But when you look at a gene,
10:48 part that we're most interested in is portion here that's gonna be translated.
10:53 right. And so something like this how we would kind of draw it
10:56 . So, so you can imagine , I got this gene with these
10:59 in the exxons. And when I my RNA, I include all of
11:03 stuff in there. And we've said are the introns useful in this particular
11:10 . What did we say? So we wanted to get rid of
11:13 . So RN A has to be . Now, this is one of
11:16 slides where there's a lot of information do not need to know. All
11:20 . You can put beside all this RN A is modified and that's good
11:25 for this class. All right. in essence, what we say is
11:28 with all these intervening sequences, we're to have to process this larger message
11:34 convert it into something that actually codes something. And so you can see
11:40 going to process, we're going to things on either end that elongate and
11:44 extend the life of the message. what the capping and the uh poly
11:49 is. Uh we're gonna modify and those introns and we can remove
11:55 So remember how I said is that are proteins plural that come from a
12:00 message. And that's what this is to show you like if I do
12:05 arrangements. In other words, you see, I got exon one,
12:08 three X on four, I've excluded over here, I've excluded one and
12:12 here. I've got them all. so each of these are going to
12:15 a different protein, but they all from the same gene. And so
12:19 is one of the ways that our is being efficient by using one message
12:23 make unique structures, unique proteins, ? But the big picture out of
12:29 this is that I start with something looks like my gene with all the
12:34 in it. And in the end process things and I get a sequence
12:39 is specific to a particular protein does make sense? So DNA becomes RN
12:49 which becomes protein. All right. , all of this is to say
12:56 going to take this from the nucleus we're going to move this out into
13:00 cytoplasm and it's in the cytoplasm where going to actually make our proteins.
13:06 right. So we've moved from one which contains the nucleic acids, processing
13:13 nucleic acids and then shifting it out the cytoplasm to do the actual processing
13:18 making a protein. And so making protein we said requires not the
13:24 it requires the RN A three different . And from that RN A,
13:29 going to add in amino acids and going to use those amino acids to
13:33 our protein. This is what protein is. So this is what this
13:37 is trying to show you. You see here, there's my message.
13:41 right here represents my ribosome which contains RIS and proteins to make or riposo
13:47 A and proteins to make the larger . And then each here those little
13:51 shaped things. Those are the And you can see over here,
13:55 carrying in a specific amino acid and , I've added to this growing
14:00 that growing chain is my protein. then after I've dropped it off
14:05 I go and I go grab another acid and I can bring it back
14:07 this protein or another one that I'm . All right. So the process
14:13 making a protein from DNA all the down to that protein has two basic
14:19 . I gotta turn DNA into I gotta turn RN A into
14:22 So, going from DNA to RN , that's called transcription. All
14:26 Many of you are sitting here listening me and are writing down notes.
14:31 are doing something called transcription, A transcript is a copy of what
14:38 started with, right? So how of you you can tell me,
14:42 can be honest with me. I'm gonna squeal on you because we've all
14:46 it. How many of you sat there in front of that math class
14:48 copied your math homework from somebody you done that? That's transcription. I
14:54 do the work, someone else did work. I'm making an exact copy
14:57 transcription. So making the DNA turning RN A transcription. All right.
15:03 RN A is in the language of acids, proteins are in the language
15:09 amino acids. I've got to change language. How many of you are
15:13 are bilingual or more? All So you can convert one language into
15:20 language that is called translation, And that's what we're doing with RN
15:26 to proteins is translating, I'm gonna the codes that I see here in
15:32 nucleic acids and I'm gonna convert it an actual amino acid sequence. That's
15:38 translation. So translation is going to a couple of things. This is
15:43 we're going back to that slide where says, where are all these
15:47 And what are they doing? The thing we need a message, the
15:50 was the transcript from that gene that processed. The next thing we need
15:55 we need three amino acids. Three acids are simply going to be the
15:59 we're going to stick to the Now, the Trnas, there are
16:04 many Trnas as there are amino And I told you, you didn't
16:08 to memorize how many amino acids there . But just so, you
16:11 there are 20 different amino acids that use to build our proteins.
16:15 how many trns are there? At 20? All right, at least
16:20 . OK. So we're gonna have Trnas, the Trnas have a specific
16:27 on their little bottom ends that recognize message and on their top ends,
16:33 what attaches to that free amino the very specific one. And then
16:37 we're gonna do is we're gonna take ribosome and we're gonna put it on
16:40 side of that message and it's going read along the length of that message
16:45 it's going to invite the TRN A with the right amino acid so that
16:50 can build that protein sequence. at some point in your lives,
16:55 you're taking a biology class, maybe of you learn this or were forced
17:00 memorize it by some horrible teacher, ? But what we're looking at here
17:06 the code, someone a couple of back broke the code. It was
17:09 big deal at the time. And said, hey, I can look
17:14 the length in these three nucleic acids the RN A is read by that
17:21 . If it sees this particular it knows to bring for example,
17:26 py alanine. And this is just you is like what is the first
17:30 ? What's the second base? What's third base? And then I can
17:33 that code. This is probably a way to see it right down
17:36 So this is the code on. this is the code right that
17:41 that's being shown up here, the A down here has the anti
17:46 And the thing that recognizes it and to that trn A is that amino
17:51 that goes with that code. All . And so we have here is
17:56 DNA, we call it a but on the RN A, we
18:01 to this as a code on. the thing that does the reading is
18:04 anticodon and then that code on codes a specific amino acid. So the
18:12 to RN A to protein, you think triple it to code on to
18:15 acid. So if you have a , you can literally, you could
18:21 in and say OK, oh here my start code on because the start
18:25 is always the same. So I to find my A UG here.
18:29 a UG there it is. That's start code on. So whenever I
18:33 an A UG, my RN A going to be red starting from there
18:37 you just read every three. So I go three, I keep going
18:40 every three and I could create my sequence. And then when I come
18:44 one of the three stop code so there's two of them, there's
18:47 third one. So we have three code ons. That's when I finish
18:51 my protein and then everything falls Now, to visualize this, I've
18:57 a picture that I think is a bit better. And again, you
18:59 have to memorize. This is just show it because there's nothing worse when
19:02 tells you something and you have no what they're talking about because there's no
19:06 . So here we have our message . We have our ribosome. The
19:10 is moving from this side and it's this way. So it's reading along
19:15 you can see it has three different . So on the front end,
19:19 is where I'm inviting in the new now, which TRN A comes
19:25 you can imagine it's basically like musical , but you are only allowed to
19:29 forward if you have the right sequence right. So we're just going to
19:34 that everything works perfectly. So as moving forward, you can see here
19:38 next coon is going to be this , this one is in the
19:41 What happens is, is we bring our uh proper um amino acid.
19:46 is our growing chain, we attach to this and when we attach it
19:49 this, we slide forward one and the one that had just been attached
19:53 gets thrown out and then that goes finds a new amino acid and you
19:57 keep doing this over and over again it occurs very, very quickly.
20:01 I think you can do something like codons per minute. It's really
20:06 So we make protein very, very in the body. All right.
20:10 this is the simple process. And , the video, if you go
20:14 that video, you can actually see the two ribosomes come along and you
20:18 it's kind of a circle of RN that's actually part of that cap and
20:21 tail allow you to create the circle it basically shows it zipping around and
20:25 protein on the as it goes around circle. Do you remember which video
20:30 talking about? Right? It's the that's on canvas. If you wanna
20:34 it not required to, it's just it's easier to visualize something that is
20:38 at the molecular level with a cartoon something. Here's this picture we've seen
20:47 already and this is kind of showing look, here's that MRN A,
20:52 those ribosomes and you can see coming the ends, these are the extending
20:59 because this doesn't look all that We can look at a cartoon.
21:02 says, here's our message, here's ribosome here. We're bringing in that
21:06 amino acid as it travels down, adding more and more amino acids and
21:10 just keeps rolling. And then as space empties out, we're going to
21:13 the next one and we keep And so you can imagine one message
21:17 result in thousands and thousands and thousands protein and it's all going to be
21:23 same protein, right? Because this one message. So this message is
21:26 same for each of these proteins that being built. And here again,
21:31 would be out in the side of . But this is here at the
21:35 endoplasmic reticulum where I'm making my protein I'm putting the protein inside the rough
21:43 reticulum so that it can be put a vesicle that can then be moved
21:48 . Now, we're gonna talk about a little bit more. But one
21:52 the things that we said is that shape of proteins matter, do you
21:57 me saying that shape matters right? turn things on and off, you
22:02 the shape. So how do we it into the right shape? And
22:07 just gonna say right here, it's because it's not well understood. But
22:12 do know some parts of it. what we do is we say that
22:15 are specific chaperones, pro these are proteins that come along and help shape
22:21 protein as it's being built again, proteins are involved, not important.
22:27 the picture shows you specific proteins. like the example here, you can
22:32 here's my elongating protein. Here is protein, here's a protein. You
22:37 see what is it doing. It's of shaping it is saying bend this
22:41 . I want you to bend this instead of be that way. And
22:44 your protein starts growing in a particular . Now, if you're wondering what
22:49 stands for and I'm sure every one you is like, gosh, if
22:52 don't know what this is when I this classroom, I'm gonna go
22:55 Those are called heat shock proteins. do the heat shock proteins? Do
23:00 change the shape of proteins? Not again, am I gonna ask you
23:04 question about that? No, but do I have to say that because
23:08 on the screen and it would drive nuts. You can see, I
23:11 this is this is an example of how biologists name things. So
23:17 the name of that protein? Can read that pre folding, pre
23:24 Why is it called pre folding? it folds, you uh early
23:29 All right. And any molecule that a, a name at the end
23:33 , at the end is a protein really where it comes from. So
23:36 pre folding protein. Great. Thanks much for the help with that.
23:40 then this is the coolest thing over . Do not worry about what it
23:44 . So the molecule you can see now being shoved into the sleeve.
23:48 sleeve is, is really more like uh Martini shaker. You know what
23:52 Martini shaker looks like. Put your in it and ice and then shake
23:56 , shake, take the top off pour out your drink. It literally
24:00 like this because what happens is you push your growing protein inside that little
24:06 shaker. This is what the chaperone . You put the cap on
24:11 you see the cap right there and this is where the magic occurs.
24:17 it out and out comes the properly protein. If the protein doesn't fold
24:23 , it can cause problems in the . It can do things that it's
24:27 supposed to do or it will not certain functions of the cell to
24:32 So making sure that we have the folded proteins is absolutely important. Uh
24:38 guys heard of sickle cell disease, cell is a function of a misfolded
24:44 . All right, it causes the in the red blood cells to line
24:50 like long change And so they're not of binding oxygen quite as well.
24:54 that's why the actual uh red blood changes, its shape is because of
24:59 long change structure that's formed by the of hemoglobin. All right. So
25:06 gonna pause. There. Are there about transcription or translation? Do you
25:11 to know the steps of, of ? Did I, did I ask
25:17 to know steps? I did not you can check your and no.
25:20 if I said yes, it would like, yeah. Do you need
25:24 know all the modifications that happened to A? No. But what should
25:28 know DNA becomes RN A which becomes and there are steps in between along
25:37 way to make that stuff happen. I say which things you needed to
25:41 in order to translate? I did have to have a message, you
25:46 to have TRN A and free amino , right? And you have to
25:49 a ribosome to go along and, read. But notice we didn't go
25:52 a lot of detail about how it happens other than a little tiny
25:56 All right. So we're keeping it . If this was a biology
25:59 we could get a whole lecture on . So I'm making a protein,
26:07 have sequences, the sequence and the become important. So one of the
26:12 that we do when we talk about is we say that there are four
26:16 levels of organization. All right. , in saying that that makes it
26:22 really, really uh complex and it isn't. All right. It's what
26:26 doing is it's, it's um and know I'm, I'm gonna be swinging
26:30 missing here. How many of you are taking calculus? OK. So
26:34 who haven't taken calculus? That's But one of the things that you
26:38 in calculus is you learn about All right. And if you've probably
26:43 that what's a derivation? It's just way to process information. And so
26:48 are derivatives of derivatives of derivatives. that's kind of what we're looking at
26:51 are just derivations of something that's complex we're taking it down to its most
26:56 level. The most simple level is is called the primary structure. Primary
27:02 simply is what is the sequence of acids. So if I started at
27:06 internal region and started reading and asking is the amino acid, what's the
27:10 amino acid? And you work all way down to the carboxy region that
27:14 be the sequence or the primary structure that protein. Every protein has its
27:22 unique primary structure. All right, it's based on that sequence. It's
27:29 , how do you spell cat, ? Right? No other word in
27:35 L in, in our language is cat. All right. When you
27:39 cat, you know it's a All right. Next is a secondary
27:47 . Secondary structure is now moving upward more complexity. And what we're looking
27:52 here are sequences or regions of sequence create a pattern. So you can
27:57 over here we've got these, these and over here you see this flat
28:02 . All right, these are examples secondary structure. They are derived from
28:09 primary sequence and the shape of remember those variable chains that sat on
28:13 side, those variable change causes these shapes. So here's the sequence,
28:21 that unique shape. And so it's unique shapes overall that give rise to
28:25 big picture, the big shape of molecule. So what we're doing is
28:29 looking at little tiny portions of the sequence or the overall structure that gives
28:35 to that shape of that overall All right. So it's dependent upon
28:40 sequence, but it gives rise ultimately the big picture. Now, there
28:44 two types of secondary structure that become important. All right, they're the
28:49 that were first discovered and I'm not sure there are more than these,
28:53 one is called the alpha helix. basically, you can see here here
28:56 the helix. It's just like a curly cue and it creates these long
29:02 like structures. You can see it , boom, boom, boom,
29:05 lots of in this one here, can see them as well. And
29:09 when you have these types of these are the types of structures you
29:13 see in things that cause fibrous right? So like collagen has a
29:18 of alpha helices in it. And shape is what ultimately gives rise to
29:23 interaction with its environment beta sheets. the other hand, are kind of
29:28 long flat areas. And so you these, these um sides that are
29:33 of uh spread out or flat, . And in in the case of
29:38 proteins, what it's doing is it's some flexibility. Sorry, let me
29:41 back. So you can see you can see there's that flat portion
29:45 so there's some flexibility or bend in region because of the presence of those
29:50 sheets. But by themselves, secondary describe a little bit about what kind
29:56 interactions can occur there. But what we, what we care about
30:00 this tertiary structure, what is the shape of the molecule? All
30:05 So the secondary structures give rise to larger shape. Um Anyone here ever
30:11 an art class, a drawing right? What are the three basic
30:16 you draw with? Let's see if knows like it's this is not a
30:23 question. You can figure we can with circles or triangles or you need
30:29 third one was the square, you draw anything in the world with those
30:32 shapes, right? Mickey Mouse is a couple of circles, right?
30:38 then we just add some dimension to . And all of a sudden we've
30:40 Mickey mouse. All right, you imagine then that given some very basic
30:47 shape, I can create any sort shape of a protein possible. All
30:52 . So those secondary structures are like three little shapes that we describe when
30:57 dry, they're like circles, rectangles triangles. I said rectangle, I
31:01 have said squares. All right. we do is we then create this
31:07 structure based on those secondary structures. that gives rise to that whole
31:13 the whole molecule. And so there going to be areas that are exposed
31:19 the outside, there's going to be that are going to be pushed
31:22 And so now we have these unique with the environment. So hydrophobic areas
31:26 hidden away from water. Hydrophilic areas pushed out towards water, positive charges
31:31 attracted to negative charges. All of things occur and give rise to the
31:36 shape, which allows it to then with either other molecules or the environment
31:42 . So what we say is the surface is where we're gonna have our
31:46 groups, right? If you want shake hands with somebody, are you
31:50 do it with your guts or are gonna do it with your hand?
31:53 if you're gonna do it with your , it's gonna be out here,
31:56 ? The things that are hidden inside body don't interact with the external environment
32:02 . And that's the same thing that's on inside a protein. So the
32:05 groups are on the outside. there's a whole bunch of different types
32:09 bonds that I'm not going to go and bore you with. But that's
32:12 of what holds everything together. And the weird one, the fourth
32:19 So primary is the sequence, secondary the, are the, the unique
32:23 tiny portions that give rise to unique tertiary is where all the actions
32:27 That's the overall shape of the but not all proteins work by
32:34 Some proteins attach themselves to other proteins a non covalent way, meaning not
32:40 a permanent way but in a, a, in a strong interaction.
32:44 they create these larger structures. This what we call Quain. Now,
32:50 in every textbook, they're going to you a picture of this molecule right
32:53 . This is hemoglobin. All And what you can see here is
32:57 1234 molecules of globin. All And the heme, if you're wondering
33:04 the heme comes from, that's a pigment that's attached to the inside of
33:08 globin. But what we have here what is called a polypeptide or it's
33:16 four different peptides that are connected And this structure only works when it's
33:23 this configuration. You've heard of collagen is the stuff that makes your
33:29 all tight or when you get old loose, it's basically long Alpha Healy
33:35 . And what you do is you 123 and then you wrap them together
33:39 another Helix. It's kind of like rope. Right? When you're
33:43 your ropes are tight. When you're , they get loose. All
33:48 But it is a polypeptide chain. it has a quaternary structure. And
33:55 , these are gonna be all sorts different types of bonds that hold these
33:58 together. Some of them will have that are non pro proteins. There
34:03 what we call prosthetics. All you've heard of what a prosthetic?
34:07 you have someone who has a prosthetic , is it a real limb?
34:11 . So when you hear prosthetic, a not part of or unique
34:16 it's not the actual protein. So is an example of something with the
34:23 . Those heme groups are pigments. right. They're not protein in
34:29 All right. So proteins have this to them and this is what allows
34:34 to do the really cool things that do. And I say cool because
34:39 a lot of them in your body they all do some really unique
34:42 Any questions about how a protein is ? Yeah. So just for
34:49 So that you'd remember if I have MRN A, right? And I'm
34:56 it into an Amina or into a chain. What's that structure that I'm
35:02 is it primary, secondary tertiary or ? What's the first thing primary?
35:08 . And then it's that sequence that rise to secondary, the secondaries give
35:12 to the tertiary. Those are the . So we good here. All
35:21 now, everything, not everything, many of the things that we've talked
35:25 so far part a larger whole. right, we talked about the
35:29 we talked about the endoplasmic reticulum, rough and smooth. We talked about
35:33 golgi, we talked about the vesicles between these places. And then
35:37 these vesicles either being merged with the membrane to open up and release the
35:42 that are inside the vesicles or to with the membrane so that you can
35:46 things into that membrane or you can those vesicles off to different structures like
35:51 example, a lysosome and these structures because they all have the same membrane
35:58 can shuttle for to make this plasma are collectively referred to it as the
36:05 membrane system. When you see that means inside. So inside the
36:10 and so basically, they're talking about , what we're doing is these are
36:14 membranes that are part of the same . All right. So everything you
36:21 at here is in the membrane Now collectively, all these things are
36:28 in metabolism. So metabolism of the , what did we define metabolism as
36:33 you guys remember came from the first all the chemical reactions in the
36:41 So the things that I make and things that I break. So
36:44 they all involved in the functionality of cell or they're responsible for taking things
36:51 where the metabolism is happening. So what the transport is. So
36:58 what are we talking about protein That would be in the rough endoplasmic
37:02 , protein transport that would be between endoplasm reticulum and the golgi and from
37:07 golgi to the plasma membrane, what metabolism and movement of lipids? Which
37:13 of those structures played a role in lipids? Do you guys remember smooth
37:18 reticulum and also plays a role in , which one played a role in
37:25 , lysosome? See, th this not as hard as some people kind
37:28 make it, right? So all these things collectively are moved are,
37:34 doing these things together. Now, I have a vesicle when I was
37:39 your seat, the the impression that got was hey, when I make
37:42 vesicle just there and it floats around a balloon on the wind and it
37:46 goes hither and on and, and know, maybe it gets to where
37:50 needs to go, maybe it And that would just kind of make
37:54 cell sound like it's luck is, driving everything. And that's not the
38:00 because we've already described inside the we have ac of skeleton and we
38:04 in those in that side of we have structure that serves as
38:09 right? So we have the microtubules are laid out so that things can
38:16 held in place or can drive And so these vesicles, for
38:23 this is an organelle, but just a vesicle are being carried by these
38:29 uh carrier proteins which are called motor and they move along things like these
38:38 . If you go back and watch that video that I suggest it
38:42 one of these molecules that looks like was Disney Corp. See his little
38:46 legs, see how it's sitting there this thing and it literally walks like
38:50 . You guys can't see it. have to get up here to make
38:52 fool out of myself. It walks this. I'm just gonna carry this
38:58 it needs to go and I'm gonna energy in the form of a TP
39:01 move this thing to where it needs go. These things are fairly large
39:06 it's a TP that's allowing this to it. Now, these molecules have
39:09 that suggest that energy is involved. they call them kinesin and dines.
39:14 Kine, when you hear kin, movement, dines, that's uh
39:19 So those are where, where the come from. But what they do
39:23 it's making sure that that vesicle isn't around going. Uh I'm just gonna
39:28 wherever the fluid takes me it's being to a, to an area to
39:33 place so that it can fulfill the that it was just required to
39:38 So, if I'm a vesicle that moving to the surface to secrete
39:43 to release materials out of the I'm being directed to that membrane by
39:49 little Disney character along a highway of tiny molecular tubes. And when I
39:57 there, I'm not going to immediately merge up with the membrane, I'm
40:01 to be regulated. So what you imagine is there's a place for that
40:06 to go. It's a dock is easy way to think. It's like
40:10 you're in a boat, you're going go up to the shore and you're
40:13 to tie up to a dock and in essence what we have here.
40:16 so there are proteins that are embedded associated uh with the plasma membrane and
40:21 the vessel that serve as docking we call them snares. All
40:27 So we have snares that are on vesicle, those are v snares,
40:30 have them on the target, that be the plasma membrane. So those
40:33 t snares and then they just kind sit there, you can see how
40:37 kind of attached them and they're ready go, they're not quite open
40:41 And so I need some sort of to tell me open up and release
40:45 materials. So this ensures that cells releasing things when they shouldn't be,
40:51 is kind of cool. Right? it's not a random process. So
40:57 , I'm a cell and she's a and I say, hey,
41:01 you, those things that you've been up, it's time for you to
41:03 those and you're like, OK, send me the signal and say,
41:06 your signal, then that's when she's release that material. All right.
41:11 remember the cells are talking to each and telling them what to do.
41:15 so that that signal in this particular inside is calcium. And so you'll
41:20 this often. Calcium, calcium, is calcium important for us and builds
41:24 bones? But most of the calcium our body plays an important role in
41:28 cells how to behave and how to internally, your muscles contract because of
41:37 . Thank you. That's the word looking for. All right now,
41:42 , this is a very, very process if you want to see how
41:45 you can look at something like And so you can see down there
41:47 is the calcium, it shows you the proteins that are involved. It's
41:51 stuff. Please do not memorize This is for if you want to
41:54 this in a little more detail, key thing to walk away from
41:58 vesicles are not moving on their They have, they're being directed to
42:03 they go, they have a place go specifically, there are proteins that
42:07 to dock and wait for a signal they release their content, before they
42:13 the work that they're designed to do in a cell is regulated. All
42:19 , there are rules that govern everything that are telling things what to
42:24 So here, I've got my vesicles are part of the indo mene
42:30 . Here's my goji. You can , I have my goji and this
42:34 trying to show you the three unique of paths that a vessel can
42:40 One I can go and I can with the plasma membrane. All right
42:46 , when I merge with the plasma , two things can happen. So
42:48 what this is trying to do is you the two things at once because
42:51 artist was lazy. All right, this case, right here, see
42:56 thing that looks kind of like a . This is what we would call
42:59 plasma protein, an integral plasma All right, the portion that interacts
43:04 the external environment is the little Y portion facing outward. Notice where it
43:10 in the vesicle, is it facing inside the vesicle or towards the cytoplasm
43:16 ? So what you're doing is you're when a vesicle merges with the
43:20 it's turning inside out because the outside the cell is the same thing as
43:25 inside of the vesicle. All So what you're doing is basically when
43:28 merge, you're basically opening up like that right. So this would be
43:34 inside. All right. So the thing that you can do is you
43:38 introduce materials into the plaid membrane when things are embedded in the membrane of
43:44 vesicle. So that's one thing that happen. So I can direct things
43:48 the plasma membrane. Second thing I do is I can secrete materials.
43:52 what the little green things here are , I'm secreting. So when I've
43:56 up to the membrane out, they , I'm secreting the materials again.
44:00 is dependent upon the snares and the and the snaps and all the other
44:03 stuff that's in those areas um allowing where it goes. Third thing I
44:08 do is I can direct a vesicle like a Lysa zone and the lysosome
44:14 has enzyme inside that. And I then direct that towards another best that
44:20 coming into the cell. And we at this process uh earlier when we
44:24 about lysosome and that's what this slice is. It's just a repeat of
44:27 slide that we used on Thursday. it says, look, here is
44:32 form part, I'm engulfing it. do I do is I bring that
44:35 and I merge it with a uh my lysosome, sorry. So I'm
44:40 it with the lysosome. And so , whatever happens to be in that
44:44 is I break it down and then can use those materials or I can
44:48 rid of things um if I don't them. All right. So I
44:54 functional vesicles like lysosomes to do some the work that's done inside the cell
45:01 these membrane bound structures. So I kind of brought everything back. Does
45:07 that all kind of make sense so ? So the inne system is basically
45:12 organelles that are membrane bound together to metabolic activity or transport. Here's an
45:17 of metabolic activity. These are the of transport questions so far. Am
45:27 sprinting through this stuff pretty quickly? , ma'am. This one.
45:35 Or this one, this one you need to know. Sorry.
45:40 So again, this is probably will stop it? How many slides did
45:45 go for like 300? Yeah. . Let's see things to look forward
45:53 . Uh huh. Good. All . So remember what I said with
45:59 particular picture. This image is a artist. All right. So if
46:03 a lazy artist, I've got to things from it a little bit more
46:07 . All right. And what it's to say is look from my
46:10 Remember what is the purpose of goi is to take these proteins that have
46:13 tagged to be directed to particular I pinched them off. Now,
46:17 have these vesicles. So what kind vesicles can I make? That's what
46:21 , that's what this thing is trying show you, all right. So
46:24 , number one is merged with Number two in this particular art work
46:28 here. So you can see I've them together. So number one is
46:32 can let me make sure I'm I'm match it to what I have up
46:35 . Um So this is secreted So number one is secreted proteins,
46:40 are all the little green dots. that's what those are, those represent
46:43 proteins. So that's number one, two is here, I can merge
46:48 , right? I can take an protein that's found here embedded in and
46:53 can add it to the surface, ? So if I wanna talk to
46:57 cells, I have to have those proteins. And so to get them
47:01 , I have to direct them via vesicle. So they're always gonna be
47:06 inward. And when that vesicle comes , remember I'm a circle and I
47:10 and I open up an outward. if I'm faced inward, I will
47:13 be faced outward. That's what that's . Yeah, now I'm part of
47:17 membrane. Let's see if this one neither of those showed the picture
47:22 if you want to see what it like in terms of opening how this
47:26 here is. Now on the look here, see how the outside
47:31 the cell is the inside. So a good way to look at
47:35 I'm scared to press the button All right. So that's what
47:39 that's what these two over here are it like this. And then here's
47:43 third, the third is, that's lysosome. All right. So,
47:47 lysosome is simply a vesicle that contains it. The enzymes that are capable
47:51 destroying something. Right. It's like digestive system of the. Pardon?
47:57 . So that's the easy way to about it is that it's digestive
48:01 And what do I do with a enzyme? If it's just sitting inside
48:04 vesicle, it's not doing anything. do I have to do with
48:06 I have to merge it with another . And that's what this is showing
48:10 . Here is a vesicle where I engulfed something that's foreign, here's a
48:15 organelle. And what I can do I can take either. What is
48:18 ? Oh, this is an So this is something I brought into
48:21 cell that might, I want to . So when you see Ino Ino
48:26 to move inward, right? So Endo Zoe is just a fancy word
48:29 saying vesicle that was formed as I things in. OK. So any
48:35 these three things are possible to merge the lysosome. So the lysosome can
48:39 a lot of different things. It destroy foreign particles, it can destroy
48:44 materials that I've carefully selected or it destroy organelles that shouldn't be around.
48:49 all this is saying, did I the question? OK. See,
48:56 be afraid to ask questions. I'll try to make it clear. All
49:00 . So if we've put all this together, I'm gonna show you a
49:04 organelle. All right. So anyone at home have a garbage disposal.
49:12 everyone has garbage disposals. But if know what one is, it's
49:16 oh, I've got stuff in the rather than scooping it out with my
49:18 , which is gross. What do do is I turn on the
49:21 shove that stuff down in there, a switch and it, and it
49:25 it into little tiny particles and off goes to the sewage plant so much
49:30 than picking up carrot shavings. All . A prote Zoe is like a
49:35 disposal. A protein is only supposed be around for a specific given amount
49:40 time. All right. And so time passes, the protein gets damaged
49:45 it's, or it's no longer And what is there are processes inside
49:51 cell that marks proteins to be destroyed like your organelles get damaged. When
49:56 have a damaged organelle, I merge with the lysosome. Lysol breaks things
50:00 . Prote Z on the other hand , oh, here is a protein
50:03 floating around the cytozole. It's damaged I no longer need it. So
50:06 mark it up with this protein called . It's why do they call it
50:11 ? Because it's everywhere. So, , ubiquitous. Yeah. And mark
50:16 up with ubiquitin and when you get ubiquitin tags, then that is then
50:20 over to a proteome and then it the spaghetti into little tiny bits.
50:24 , it makes free amino acids. can I do with the free amino
50:28 ? I can make new protein kind cool. Right. So this is
50:32 , a way of getting rid of you don't need and making available amino
50:36 that you can reuse. So kind cool. All right. So it
50:42 to regulate appropriate function. It's how control proteins and at what they
50:47 And as I mentioned there, it's broken down with ubiquitous. Now,
50:53 is energy dependent. Most of the in your body are energy dependent.
50:57 I'm just kind of highlighting that for just think, oh proteome, it's
51:03 disposal for free floating proteins. So you kind of see here,
51:08 regulation taking on taking place inside a . And as I promised, we're
51:12 into that last little section of the where what we're gonna be dealing with
51:16 some more uh psychological concepts rather than structures. And granted this is micro
51:24 . I guarantee you, I I promise after the first test,
51:27 really do anatomy. This isn't just , horrible freshman biology. OK.
51:33 what we're gonna do is we're gonna at some processes here that allow for
51:39 to uh communicate and to ultimately do work that they're gonna do and we're
51:45 start with the process of diffusion. , if you look around the
51:49 would you say that we're more or equally spread out? I mean,
51:53 more or less, I'm not saying spread out. Would you say we're
51:56 or less? Yeah. I generally speaking, what we do is
51:59 walk into the classroom, we look and say, OK, where is
52:01 empty space? We sit down and like if the first person in the
52:04 were like, yes, I can wherever I want to and then people
52:07 showing up, you're like, damn . People are sitting next to me
52:10 , right? And that's kind of molecules do. They want their elbow
52:13 . All right. And so given to move, right? If you
52:19 molecules and you put them close together then you remove that constraint, what
52:24 will do is they will then freely so that they're equilibrated with equal distance
52:31 them. And again, we've grown to the mosh pit picture, the
52:35 pit image in a mosh pit. are dancing and they're throwing elbows and
52:39 get to the point where everyone has of the same amount of space in
52:43 them. And that's when everyone's kind comfortable and happy. And then that
52:46 jerk comes rolling in swinging arms and and then it causes all sorts of
52:51 . That's when they start running into other. All right. So diffusion
52:57 when everyone kind of spreads out All right, there's an even
53:03 So that's what we're showing out Now, the rate at which this
53:07 is gonna be dependent upon two All right. And these concepts are
53:12 everywhere. All right. So the has to do with gradients. All
53:17 . Now, the concept of gradients going to be a common theme that
53:20 gonna see over and over and over over in this class. So learning
53:23 once and then just applying it to you're looking at when you see a
53:26 is like OK, this makes So we're using chemicals right now,
53:29 I want you to think about it this. If I'm sitting on a
53:32 in Houston, what is Houston like if I get and stand on a
53:37 ? Am I gonna move anywhere? . So how do I get the
53:41 to move? I can either push I get on a slope,
53:45 So if I get on a shallow , am I gonna move fast?
53:49 so bad, but if I get a steep slope, am I gonna
53:52 fast? Right. So yes. here's the concept the steeper the
53:58 the faster things go. Is that that's easy to remember for everything,
54:05 ? And that's what's true about If I have lots of stuff over
54:10 and very little stuff over here, difference between those two sides is
54:14 very steep. So the rate at things are going to diffuse away from
54:18 area of high concentration to the area low concentration is going to be
54:23 All right. But if I have here and just a little bit less
54:27 here, so if the slope is this, the rate of diffusion is
54:30 to be a lot slower, That kind of makes sense.
54:35 The second thing that affects the rate diffusion is temperature. Now, when
54:40 think of about temperature, we think and cold, all right. But
54:43 really is the presence of energy, energy specifically. All right. And
54:49 again, back to the mosh if people are in the mosh pit
54:53 like they did in the early two , whereas like this, everyone's just
54:56 of like this is cool, You know, you're not gonna have
54:59 lot of people bumping into each right? And there's not a lot
55:02 energy, right? But if you like we did in the eighties,
55:06 is basically throwing fists and elbows and kicks here and there, right,
55:11 you're gonna have people bumping into each all over the place. That's where
55:14 mosh pit is a lot of All right. So when there's lots
55:17 energy, gee sorry, lots of , there's a lot of movement and
55:21 lot of movement cause a lot of bumping in to each other. And
55:25 you're gonna see the fusion occur a quicker. Now, to demonstrate
55:29 I'm gonna use something that's simple that of you may not know. But
55:32 probably familiar with anyone here know how make um a Southern sweet tea.
55:38 , I see like three hands. right. So, but you all
55:42 about what sweet tea is. Sweet is tea and sugar. See it
55:46 it in the name sweet sugar. . All right. So let's say
55:50 go up north, you know just . Yeah, you're already shaking your
55:54 like they don't know what they're drinking there. All right. And you
55:57 a tea and you taste this, like that bitter, horrible stuff.
55:59 you're like, no, no, , this guy this doesn't taste
56:01 right? It needs sugar. So you do is you take that tea
56:05 you start dumping sugar into it, ? And you watch that sugar and
56:08 does it do? It goes right to the bottom of the glass and
56:11 really disappointing because you know now it's be bitter with sludge. So what
56:14 you do? Take a spoon and start adding energy to the system and
56:23 start swirling that stuff around and that begins to dissociate and it begins to
56:28 throughout all the sugar. So that the tea. So the tea is
56:32 sweet. Now for though, you how to make sweet tea or if
56:36 mom or your grandma make sweet tea you. It's real simple. What
56:39 you do? You take the boiling water? You put your tea bags
56:43 it and after you get that tea has done its steeping, you take
56:47 tea bags out and you pour in sugar directly into the hot fluid.
56:51 fluid already has kinetic energy. And what does that sugar immediately do?
56:57 dissociates and dissipates because it has kinetic already. All right. So temperature
57:05 kinetic energy. If I add kinetic to a system ba for diffusion,
57:10 all it's saying. Now with regard diffusion, there are different types of
57:19 . When we talk about diffusion, talking about all the different types
57:23 There's one that's called simple diffusion. this is simple diffusion. I have
57:26 molecule, here's my lipid bilayer. you can imagine my plasma membrane,
57:30 I have a molecule that can pass that lipid bilayer. In other
57:34 it is lipid soluble, then I need help to get past that.
57:40 would be simple diffusion. All So I don't need a transport
57:44 I can't regulate. It's going to be governed by those two rules.
57:47 the rate of diffusion based on the and how much kinetic energy I
57:51 All right. So molecules can move and forth and reach some level of
57:58 . But most molecules in the body not lipid soluble. Most of the
58:02 in the body are water soluble, we call lipoic. All right,
58:08 hydrophilic, they love water, they fats. And so if I want
58:12 move a molecule across the membrane, gonna have to use help. In
58:19 words, I use facilitated diffusion. , there's my help facilitate is to
58:25 . All right. So facilitated diffusion I have some sort of protein embedded
58:30 the membrane that I can use to me across that membrane. All
58:34 Now, typically what we're talking about we're talking about facilitated diffusion for the
58:39 part deals with molecules moving down their grades because that's what diffusion is.
58:44 moving in the direction that is where less of this stuff. And I
58:50 use a channel. A channel is you see here where I have an
58:54 path that is uh water filled. molecules can move all the way through
58:58 . If I open that door and it open, that would be an
59:02 of a channel. All right. then there's also another type of molecule
59:07 called a carrier. A carrier is open to both sides at the same
59:13 , it's open to one side and it binds up to the molecule it's
59:17 and then it opens up to the side. And that's what this is
59:19 to show you the best example I come up with that you might be
59:23 with is those, uh, rotating that you see at the airport,
59:26 some hotels, right? You understand what I'm talking about. You
59:30 , like you go in and like, get in there and you
59:31 to do the whole little thing around edge. It's, there's a point
59:35 you're not open to either side. you ever get that fear that you'll
59:39 trapped in there? Yeah, especially you have that person pulling the luggage
59:42 they get stuck. All right. that's more like the carrier. It's
59:47 open one side or the other. , these are considered passive because they
59:52 require external energy, right? They're passive because they're following the rules of
59:58 fusion that we learned over here. concentration, low concentration, I'm moving
60:04 an area of high concentration down that area of low concentration. But you
60:08 see I have another type, this active transport and active transport um is
60:14 form of trans transport where I'm not down a concentration gradient, I'm being
60:21 or moved against the concentration gradient. right. So an example would be
60:27 for example, if I have a and I put it on a
60:31 the ball wants to roll off the and go to the floor. It
60:34 require any energy other than a little of passive energy to kind of get
60:39 go because gravity pulls it. But put that ball on the shelf,
60:44 have to move against the pull of . I have to put energy into
60:48 system to move the ball. All . So that's kind of the same
60:51 that we're dealing with active transport. have molecules that are already on the
60:56 of, of where the lower concentration , I can't move uphill. So
61:01 have to have energy that moves me . And this is where the active
61:05 comes along. So there are two of active transport. One's primary primary
61:10 when I'm using energy directly on the . So in this particular case
61:15 you can see the molecule I want move in this direction. I got
61:17 over here, I got more over . I don't want the molecule doesn't
61:20 to go that way. But what do is we allow it to bind
61:24 that carrier. The energy comes along directly to this in primary, which
61:30 the thing to open up and basically this thing to the side that doesn't
61:33 to go that would be primary secondary transport doesn't use energy directly, it
61:42 energy indirectly. All right. So is a little bit harder to
61:47 but I'll show you an example a bit later. But the idea is
61:50 energy in a system like this creates concentration gradient, concentration gradient is stored
62:00 . And so I'm gonna use the energy in my concentration gradient to drive
62:06 movement of a molecule against its All right. So the energy is
62:10 up as potential energy like what you here. And again, I have
62:13 better example a little bit later trying show you this here is not gonna
62:18 , but I'm not using the energy a TP I'm using the potential energy
62:23 the concentration gradient to move something. right. So just kind of put
62:28 pin there for a second. Say going to come back to it to
62:31 you the example. OK. You with that for right now. All
62:36 now, diffusion is dependent upon a of things. All right. First
62:42 matters, thickness matters, surface area what I mean, size matters,
62:49 matters because the size of the solu , the bigger the size of a
62:54 , the harder it is for it move. The example I'm gonna use
62:57 . Uh Here is I have four . I've told you when they were
63:01 , uh they're a little tiny gas , they moved everywhere. And so
63:04 have twins, right? I have sets of twins, you know what
63:06 like to do, they have to in the opposite directions all the
63:10 right? So you have to like you have one, the other one's
63:13 go the other direction. So you to watch them and when you're dealing
63:17 crowds and twins, not only do like to go in opposite direction.
63:20 like to go between people's legs. right. So imagine a big
63:23 like at a football game, it's the halves or something like that.
63:27 kids go off in opposite directions. they going to disappear into the crowd
63:31 that? Yeah, because they can between everybody's legs and go. Look
63:36 me. I'm a big guy. can't zip between legs. I have
63:39 bump into everyone and say, excuse , excuse me, pardon me?
63:42 size matters, the bigger the the harder it is for it to
63:47 . OK. Second thing that matters thickness of the membrane. All
63:52 thickness of the membrane refers to how the membrane goes this way.
63:56 it's very, very thin, passing something that's thin, doesn't take a
63:59 of effort. But if it's really , I have to move through all
64:03 portions that, that make up that . So it's harder to move through
64:09 . So that slows down the rate diffusion surface area matters. All
64:14 Again, we go back to the , we have four doors that we
64:17 see here, we can move people , diffuse out of this space fairly
64:21 with those doors. But to increase exit, that would be increasing surface
64:28 , what would I do is I more doors? So if I added
64:31 doors, more people can leave So the greater the surface area where
64:36 can take place or movement can the faster things diffuse. Now,
64:40 should make sense, right? If have, if I take away the
64:44 , are we able to leave the faster or slower? Slower? Thank
64:49 . All right. Uh What else got? We got the magnitude of
64:53 concentration grade. We've already said that , the more you have over
64:56 the higher the concentration versus over the faster you're gonna go. All
65:01 temperature, we said matters, the energy you add to the system,
65:04 faster it goes. And the last is the viscosity of the solution that's
65:09 referring to the thickness of the solution . All right. So if you
65:13 more things to bump into along the , the harder it is for you
65:17 diffuse. All right. Uh An would be water versus ketchup. Ketchup
65:23 thick, it's viscous. So things through ketchup would have to run into
65:28 the particles. If you're diffusing something water, it's going to move
65:31 very quickly because there's not a lot particles, all the particles are uniform
65:34 size. So there's some language that with this, all right, the
65:46 of diffusion is referred to as If you look up at this top
65:49 or the top three pictures, what can see here is diffusion taking
65:53 This is the flux on the left you see the real little red
65:57 there's infinite the the concentration gradient is on that side than on the other
66:02 . So the rated diffusion is going be really, really fast. But
66:06 particles start moving across now the rate diffusion begins to slow down. And
66:14 , what you're gonna do is you're end up with equilibrium. Now,
66:17 have the same number of particles particles stop moving when equilibrium occurs, they're
66:22 moving, some are moving to the , some are moving to the
66:26 But what you have is you have rate of diffusion in both directions is
66:29 same. So we have equilibrium You've taken chemistry. This is what
66:35 chemistry, one is all about is equilibrium everywhere. All right. Now
66:41 your body, you don't just have molecule, you have thousands of molecules
66:46 we're gonna make it simple, we're keep it to two. All
66:48 So over here we have flux in direction. With the blue particles,
66:52 have flux in that direction. All , they're de independent of each
66:57 They're not working together. All But if we look at the rate
67:04 one side to the other, that be the difference between those two would
67:08 the net flux. All right. the net flux is the rate of
67:13 in this direction versus rate of diffusion that direction. And you can see
67:17 this case, we've reached equilibrium. even here, this would be the
67:21 flux would be moving in this direction that direction. So Netflix just refers
67:27 the differences between the two sides and directions that are moving out of those
67:32 . All right. Now in your , we have a type of diffusion
67:37 taking place, it's called bulk All right, we have it in
67:41 very easy examples that we look at right, when you breathe in and
67:46 you breathe out, what are you in and breathing out? That was
67:53 long answer. Let's keep it What are we breathing in and out
67:59 ? That's what I'm looking for. is air now is air oxygen?
68:06 . Huh? OK. What is air then? Nitrogen and in
68:17 in other stuff, it's 79% 20% oxygen and less than 1% of
68:23 a billion other things. And that water and smoke and dust and,
68:28 all sorts of hair cells and all of things. All right. So
68:33 I breathe in, what does my want oxygen when I breathe out?
68:38 is my body trying to get rid carbon dioxide? All right.
68:42 notice those two things aren't exactly the thing. So when I breathe
68:46 am I breathing in carbon dioxide? , I am. It's not excluding
68:51 dioxide. So air coming into into my lungs has carbon dioxide in
68:56 . But my body doesn't care about . Right. So when I'm
69:00 breathing in and I'm breathing out, called bulk flow because there's not a
69:06 to the materials that are moving in out of my lungs. Right?
69:10 all going at the same time. right. This is the easiest example
69:15 we look at campus and the movement people between classes, there are people
69:19 in the classrooms, there are people out of classrooms, right? But
69:22 could look at what is the net of people. And that would be
69:27 flow. The idea of what is movement of the people. All
69:32 So bulk flow refers to the non movement of an entire solution of material
69:41 a specific area. From an area high pressure to an area of low
69:45 . This is why I like to the lungs. It's easy to think
69:47 , right? When I breathe in pressure, low pressure. All
69:51 it doesn't matter what I'm breathing, breathing in mostly nitrogen. But all
69:55 care about as least as my body concerned is the oxygen and then I'm
69:59 do some exchange that takes place. when I breathe out, I'm mostly
70:04 out nitrogen. Plus I'm getting rid some excess carbon dioxide that I
70:10 And I'm breathing out some oxygen too my body wants. But tough,
70:13 gonna have to wait. We'll get that in a MP two. When
70:16 talk about the lungs, membranes are as being permeable, impermeable or selectively
70:27 . I'm just going to describe what terms mean. Permeable means it allows
70:30 passage of a given substance. All . So when you look at a
70:34 and say, oh, you are to x, what you're saying is
70:37 stuff isn't going to be stopped, moves through. So this would be
70:41 example of membranes are permeable to For example, they're small, they
70:47 can just kind of move wherever they to uh hydrophobic molecules. Basically anything
70:52 hates water can move through a membrane they're lipophilic. Um anything that's small
70:57 polar are, those are like the exceptions to the rules. So if
71:02 polar, you like water. All , that just as a rule,
71:05 like water, but water can diffuse the plasma membrane just fine. What
71:13 know, it just does. Because it's small, small things go
71:16 they want to for the most All right. But then you can
71:20 impermeable. So if you're large, example, a large polar molecule wants
71:25 hang out with water, it it's excluded from the plasma membrane. So
71:31 say the membrane is impermeable to large molecules. All right. So if
71:36 look at overall what is the membrane ? Well, it allows some things
71:39 pass, allows other things not to . So it is selectively permeable to
71:45 substances. All right. That's what permeable means. It is permeable to
71:51 things and impermeable to other things. that's what your membrane is. All
71:59 . This is the part where I'm , uh yeah, it's not
72:03 It's just we like to make it difficult for ourselves. You guys have
72:08 learned about osmosis at least once in life. Yeah. Yeah.
72:12 Yeah. Trying to. All osmosis is the diffusion of water.
72:17 you know that diffusion means things moving an area of higher concentration in an
72:21 , low concentration, then osmosis is movement of water from an area of
72:26 water concentration to an area of low concentration so far. Does that make
72:32 ? Does that make sense? It make sense? Right. But in
72:37 , they like to confuse you and throw in a whole new term,
72:40 say, oh it's an area of from an area of low solute concentration
72:43 an area of high solute concentration. all of a sudden your brain
72:47 wait a second. That doesn't make lot of sense to me because water
72:50 what I'm talking about. Why are talking about Solus? And the answer
72:55 because chemists don't care about water so . They care more about the
72:59 They, they want to know about solution, the materials in the
73:03 So that's where their focus is. see if I can do this in
73:08 a way that makes sense. this is why you come to class
73:17 you get the bonus. All Keeping in mind I can't draw to
73:22 my life. All right. If have a space, let's try this
73:28 . Here we go. If I a space, the air, the
73:31 inside that space, we're just gonna it 100%. That makes sense so
73:36 . So, here's 100% of If I have lots of water,
73:42 gonna call that 75% water. What's other percentile? What is it?
73:50 of something? So, all we're just gonna call it.
73:55 all right. If I put it to another space, that is
74:01 All right. And that space has water, it's 75%. What
74:12 All right. So when you visualize , it's a lot easier to see
74:14 this way. So which direction if membrane right here is impermeable to so
74:20 , but is permeable to water. direction is the water going to
74:24 It's going to go from the area high concentration to the area of low
74:28 of water. So, osmosis isn't special. It is just the diffusion
74:34 water. You just have to consider is in the space with the
74:38 So water is being driven towards where less water. That's all it
74:43 It's drawn or attracted to the area less water. All right. With
74:48 in mind. What drives it? right. This is probably where we're
74:53 end today. Um Unfortunately, I'm a slow talker, I guess.
75:00 right. So first off, we hydrostatic pressure, hydrostatic pressure is simply
75:05 pressure of any fluid on the walls the container containing it. All
75:11 So I see down here, this probably not your water. Maybe it
75:14 . Can I steal this because we visualize is this, is this your
75:19 or is this left? All So this is scary water, unknown
75:23 . All right. So the water this container, where does it want
75:26 go? Does it want to just in the container? No, it
75:30 to get out, right? It to spread out as thin as it
75:33 can. All right. But it because the pressure that it is exerting
75:38 is less than or is less than equal to the pressure being caused by
75:43 wall of the container, right? I make the water come out of
75:47 container? How by increasing, I crush it by increasing the pressure of
75:54 water outward, right? So if start squeezing this, don't be
75:58 I'm not gonna actually break anything. right. If I start squeezing
76:02 I'm creating more pressure inside the container the water is trying to escape
76:06 This is hydrostatic pressure. So all containers have a hydrostatic pressure in
76:12 It's just the the pressure of the . All right, an osmotic pressure
76:18 a hydrostatic pressure. It is a pressure that opposes the movement of water
76:25 that space. Ok. So we get confused. So you'll see things
76:30 oh, water is gonna move into space. But then eventually there's gonna
76:35 a point where the water stops right? Why does the water stop
76:39 ? Because the pressure inside that container now greater than the pressure moving that's
76:45 the water inward and it opposes the and basically kicks the water out.
76:50 , the visual thing that you can here is I want you to think
76:52 a smart car. You know what smart car is, right? It's
76:56 little tiny cars that you can pick and put in your pocket,
76:59 How many people can you fit in smart car? You say too,
77:03 haven't tried hard enough. You can more than it because there's a
77:08 right? You can take like three . There's still room, there's,
77:13 can put four people maybe 56 I didn't say how many people can
77:18 fit in a smart car comfortably? said, how many people can you
77:21 in a small smart car? You probably get to about eight people and
77:25 you get that ninth person. You that person into the smart car.
77:27 gonna happen on the other side? gonna pop out, aren't they All
77:31 , there's a point where the pressure the car says, uh uh this
77:35 the finite limit to how many people can fit into the car. That's
77:39 the osmotic pressure is. It's like pressure inside the smart car. I
77:42 keep adding in water into a container the pressure inside there. That hydrotic
77:46 becomes so great that it says you one more molecule of water. I'm
77:51 out a water molecule. That's the pressure. So the osmotic pressure is
77:56 point where the hydrostatic pressure on the side opposes osmosis. All right.
78:04 osmosis is being the diffusion of water an area of lower concentration. I
78:11 have. Yeah, I'll do this it's related. You guys are all
78:16 on going into the field of You're planning on being nurses. For
78:20 most part, this becomes absolutely Tonicity refers to the ability of a
78:27 to cause a cell to either gain lose water. Why is this
78:32 If you have someone who shows up the er who's dehydrated, you give
78:35 pure water no, very bad. going to cause the cells to pop
78:40 the water is going to go flooding the cells because there's more so and
78:44 nothing opposing its movement. So it's to cause the cell to swell
78:47 swell up, swell up to a where it's like, oh and it's
78:50 to lice. So what we do when we have someone who's dehydrated,
78:54 give them water plus solute. All , we give them D five LR
78:58 lactated ringers or something fun like All right, what we're doing is
79:03 giving them less water, but we giving them water that's going to slow
79:07 rate of diffusion. So tonicity refers what's happening when you put a solute
79:14 you have a salute, you put cell in. What's going to
79:15 Is the water going to go rushing or is the water going to come
79:19 out of the cell or is it to stay the same? So that's
79:22 these three terms refer to hypo iso hypo is less ISOS same hyper is
79:28 . The second part of that word tonic. It refers to the
79:33 all right. So it refers to solute concentration. So more sol
79:38 same solu solution less so solution. so what he's doing is comparing it
79:43 the cell. So isotonic has the amount of solute as inside the
79:48 So water movement in and out of cell is going to be in
79:52 So you're not going to see a or a loss if I have a
79:56 solution, that means I have So that means I have less
80:00 So that means water is going to rushing out of the cell and the
80:02 is going to shrink. But if give a hypotonic solution that's less,
80:08 more water. So water is going rush into the cell. And so
80:13 important to know with regard to What's going to happen is water going
80:19 move in or out of the cells we come back, what we're going
80:23 do is we're going to deal with question of proteins and how they play
80:27 role in trans membrane transport. You have a great
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