| 00:00 | Oh yeah. Okay. Yeah Right. Hey folks. Uh |
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| 01:15 | Uh Let's see. So today um on with chapter nine finish up chapter |
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| 01:27 | 1. Remember that flip class? a bunch a bunch more questions. |
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| 01:33 | I think we'll get through at least . Um But the so remember the |
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| 01:43 | dates for these things and then the mentioned last time about midterm grade. |
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| 01:48 | so I'm in the process of almost that so you'll be able to see |
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| 01:52 | tomorrow sometime tomorrow. So uh late , early afternoon. Um So it's |
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| 02:01 | um it's uh it's like regular. um The extra credits included in |
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| 02:13 | Okay even though as a credit for out the evaluation, even though you |
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| 02:17 | done it yet obviously. So that's all figured. Okay Um so um |
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| 02:23 | points 3-23rd. Okay. Not to 23rd and first the is inquisitive And |
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| 02:37 | 12 so all that and so it's a it's very accurate estimate. Okay |
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| 02:46 | I mean it's something that you can use that value as a way to |
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| 02:50 | you know what you need to do get where you want or whether you're |
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| 02:57 | um uh what was the other thing was um But kind of details of |
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| 03:14 | the of the calculation but anyway so have that information which I'm sure you |
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| 03:21 | . So um I think that was my hand about that stuff. Any |
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| 03:30 | about anything. No. Alright. so let's um move ahead. This |
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| 03:39 | I just kind of put this stuff we've been talking about in Chapter nine |
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| 03:44 | from last time. So, it's of Put this in perspective I |
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| 03:51 | So we're looking at uh we looked in 78 the Terrio genome gene |
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| 04:01 | Right. Um Kind of building toward couple of things. One the checking |
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| 04:08 | kind of covers this is how Coqueiro can introduce variation into the population. |
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| 04:15 | , sure. They can reproduce by fission. Alright, that vertical gene |
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| 04:21 | allows them to pass genes to the generation. Then they also have this |
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| 04:25 | to receive transfer genes from other members the population. Right? Um Transfer |
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| 04:35 | we've uh just you know, sunrise that upper right figure there uh production |
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| 04:44 | . Right. So um since book can't reproduce sexually. Right. Which |
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| 04:52 | introduce a lot of variation as has with us and other imperials. They |
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| 04:57 | have this ability to exchange and transfer which again introduces variations of population. |
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| 05:07 | So we covered transformation and are going congregational. All right. So, |
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| 05:15 | know, the kind of things are to students. Genomic islands. |
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| 05:18 | So these are like transferable region. You kind of need to be transferred |
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| 05:26 | a plasma uh are of a similar . Of course. Right. But |
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| 05:32 | it's a disease causing mechanisms pathogenesis. islands transferred virulence factors like a capsule |
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| 05:41 | these kind of things toxins. Somebody islands, particular components involved in setting |
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| 05:46 | the the bacterian interaction uh typically pathways can give them uh an advantage on |
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| 05:55 | certain conditions. So anyway a couple things. The importance of recombination. |
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| 06:02 | already seen that the combination is how an acquired segment of D. |
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| 06:09 | A. Can become part of its by combining with the chromosome check. |
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| 06:16 | Sorry thank you. Kind of touches everything. So we'll go through |
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| 06:21 | we'll finish conjugation with the transaction Let me just show you this a |
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| 06:27 | of animations here. Okay so this the F. Factor conjugation. So |
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| 06:35 | the what we have is a room have many pairs A we have a |
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| 06:43 | factor factor is the portion of that . So we're transferring plasma is here |
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| 06:50 | that contains the genes that enable trans . So sex pilots uh the component |
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| 06:58 | kind of helps bridge themselves together so kind of components that facilitate the |
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| 07:03 | Okay and so uh that uh then with an F. My cell. |
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| 07:10 | so we see here the process let's flip this forward here. Okay so |
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| 07:17 | it begins with the extension of a pilot, assist religious politicization of that |
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| 07:23 | to lengthen it. You see the and the factor in the in the |
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| 07:30 | cell that we have. Just kind slow. Okay let's speed it up |
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| 07:36 | little bit there we go here comes recipient cell contact with it and then |
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| 07:43 | have subsequent depressurization to decrease. That's much stronger connection, stable connection. |
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| 07:52 | then um mobilized the uh classify said . What we're talking about is properly |
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| 07:58 | . Moving it, moving a copy the recipient in china. And so |
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| 08:04 | so that's going on. And so can have uh transfer. Then the |
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| 08:08 | circle replication mechanism, right kicks And so now we have an f |
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| 08:14 | has become an F plus set. . And so as you watch |
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| 08:21 | something something's happened, what happened to X plus cell? What kind of |
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| 08:25 | did acquire that didn't look bald And then all of a sudden grew |
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| 08:32 | after the connection. Right hair Right? Probably embryonic gene. Some |
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| 08:38 | that inherited because the point being, it inherits, of course potentially express |
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| 08:45 | in this case. Uh It was some kind of of. Right? |
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| 08:52 | um so that's your basic F plus minus congregation. The f minus |
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| 08:58 | Recipient becomes an F. Plus. let's look at the HFR. |
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| 09:05 | let's go back to hear this. uh here. Okay, so here's |
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| 09:14 | H. F. R. pause that um and so integral plasma |
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| 09:21 | into the chromosome. Like So so got yeah, so now we have |
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| 09:27 | course the chromosome with the integrated Right, so now the plasma cell |
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| 09:31 | still left plus, it's just the is in been integrated into the |
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| 09:36 | So what that means though is the chromosome can become mobilized now. |
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| 09:43 | So uh so we're gonna see that . And it sort of makes with |
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| 09:48 | f minus cell here it comes. the same process uh they come together |
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| 09:57 | then So now instead of transferring the that were carrying out copying of the |
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| 10:04 | now the thing to remember is that is the part back here that contains |
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| 10:12 | transfer genes. That this is essentially makes it have plus. Okay. |
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| 10:18 | you know, this is the part gonna if if it were to |
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| 10:22 | this would be the very last That would probably get transferred to the |
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| 10:25 | cell. Right? But we're going see that that doesn't happen. |
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| 10:29 | So we see the dropping. So it is. So they don't stay |
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| 10:34 | enough together for that part could be . That's why this f minus stays |
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| 10:40 | an f minus. Okay, you to be together for a long time |
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| 10:44 | this to occur. And you see the uh back up a set, |
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| 10:53 | now this anonymous DNA is eric if combined, All right, it would |
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| 10:59 | to this would have a very probably lifetime would try to cool exist as |
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| 11:04 | piece of DNA. So to to make a more permanent part of the |
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| 11:09 | . Uh it has to recombine. ? And so that of course means |
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| 11:14 | has to be some level of similarity between you two because it's all about |
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| 11:22 | , the documentary base pairing. so now we have that minors |
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| 11:25 | States of mind because they did not not able to inherit that last bid |
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| 11:30 | is the transfer the F. Plus that enable it to be transferred. |
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| 11:35 | um So It crushes by the 18th . Okay so I'll summarize here on |
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| 11:43 | next slide. Just go to Uh He here. Okay so uh |
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| 11:51 | what we just that's the first We saw that this basic F. |
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| 11:55 | F minus congregation. Um The I this picture can be a little bit |
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| 12:04 | because you're seeing it from minus cell the plasma already in but it initially |
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| 12:09 | have it of course that inherits the and then that returns mixing F plus |
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| 12:15 | HFR. Again the integrated class read to an F minus cell. But |
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| 12:22 | minus typically stays as F minus. then we have another another process. |
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| 12:32 | that um is what we call the . Prime factor. So very quickly |
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| 12:38 | then when you see that, when ask the question first, before you |
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| 12:42 | that. So uh the formation of prime factor required what I think you |
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| 12:49 | know one of those already. Haven't that picture. Every crime factors. |
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| 12:55 | this has to do with them. if the plasma can integrate the chromosome |
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| 13:05 | then it can come out as well it kind of relates to that |
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| 13:09 | Okay. Mhm. Open the reset sorry? Okay wow. Okay Here |
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| 13:55 | go. Yeah. And to our are ahh ahh Marcel and excision two |
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| 14:20 | . C. And E. So what this is about as I |
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| 14:27 | , HFR size integrated plasma. So can also exercise. I'm not in |
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| 14:34 | nature of our cell. I'm not the frequency of you know how often |
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| 14:40 | comes out. Okay. But if does come out then what does exercise |
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| 14:46 | means to come out exercise out of pro zone, vast majority of |
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| 14:57 | But when it is what comes So but that doesn't mean here in |
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| 15:01 | . Right? The integrated F Right? This is a plasmid that |
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| 15:05 | in all purple color. Okay, in a normal excision, that's what |
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| 15:11 | out. Ok. But an Prime factor results when that cutting, |
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| 15:18 | to speak. Think of two scissors are cutting right? That those scissors |
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| 15:25 | left or right slightly. Okay, in this case we're moving slightly to |
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| 15:31 | right. So that what we're what's being cut out. Is this? |
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| 15:39 | , that's what comes out that happens as a frequency. They're one in |
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| 15:42 | million times it happens like this. other most of the time is |
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| 15:50 | Right? So what happens is this in this example the B. |
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| 15:57 | B genes there will be jean stupid . A lot. Okay. The |
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| 16:10 | gene will kill you. Let's try . Yes. Victory. Okay. |
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| 16:26 | The B gene which is on the and catholic was part of the chromosome |
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| 16:30 | now it's coming out with that B . So probably should stay behind but |
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| 16:34 | not because of the excision. So that becomes part of the |
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| 16:41 | But then also then this part of plasmid stays behind, Right? So |
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| 16:48 | stays behind and a new part goes it. All right. So that's |
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| 16:51 | you see here as it is. recombination occurs right? Here is the |
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| 16:57 | B gene. Right. And then the end result is we have a |
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| 17:04 | . So we call it F prime it when it when this kind of |
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| 17:07 | occurs where his words picking up this from the chromosome. But then I |
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| 17:13 | remember that part of it's left Okay, so that's the F |
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| 17:18 | And so what's the big deal about ? Well, the big deal can |
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| 17:22 | if it congregates this. This cell with another member of the population. |
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| 17:27 | same population then you might generate what's a partial difficult. Okay, so |
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| 17:35 | we are all full deployed. Um heard of genes from both mother and |
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| 17:43 | but apart from deployed only hands, know, less than that. Of |
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| 17:47 | . Right. And so uh so actually be jean uh and so that |
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| 17:55 | be a benefit that that be gene evolve independently. So whatever the the |
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| 18:03 | is, um it can still do function but then this extra one can |
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| 18:10 | know, as I said we evolved . Maybe it acquires a mutation or |
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| 18:15 | . Maybe enabling a slightly different activity be benefits to sell. But um |
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| 18:22 | maybe it had a bad uh nonfunctioning BG. And now baby inherits a |
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| 18:30 | version. And you can then then you don't realize that pathway. So |
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| 18:35 | different benefits from being a partial did like this. Okay. Um very |
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| 18:43 | about. Okay so here again is summary of all three of these |
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| 18:49 | This is the last one we just about. Okay so the age of |
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| 18:52 | cell uh and the kind of strange that occurs to generate potentially crime. |
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| 19:00 | mean prime potentially a part of the . Okay so um all right so |
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| 19:10 | is trans deduction. Right so we transformation propagation not transaction. This is |
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| 19:18 | our virus. Okay so we've gone viruses already. So um generalized |
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| 19:25 | Think of a lightweight fage. Political page would go through a cycle |
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| 19:33 | this. Okay uh genome entry began the genome, viral replication of viral |
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| 19:42 | etcetera and um breakdown of the host occurs as part of the cycle. |
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| 19:50 | then what happens is an error in occurs. So the viruses packaging viral |
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| 19:55 | and the caps it and then by packages host D. N. |
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| 19:59 | Instead. Okay so now we've got particles containing host D. N. |
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| 20:07 | . Okay so the cell virus kills cell virus breakout and then um they |
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| 20:15 | another set. So any host cells infected by? Hey hey virus fage |
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| 20:25 | host DNA. This guy. Okay of course it's not going to kill |
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| 20:31 | cell because it's not carrying the viral . So but what can happen is |
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| 20:37 | it's the portable mechanism of getting the hosting into that cell. Okay and |
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| 20:46 | uh the combination would have to occur course to allow that fragment to be |
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| 20:52 | to survive. But it nonetheless is up jeans right from that previous host |
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| 21:01 | . Right um and so uh and thing about generalized transaction is potentially any |
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| 21:14 | gene in this previous host Any any these fragments can be incorrectly packaged in |
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| 21:22 | virus which means potentially any gene can transferred this way. Okay that's in |
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| 21:30 | to specialized transaction. We'll talk about in a second. So here theoretically |
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| 21:36 | previous prior hosting can be transfers. . Um So specialized transaction. Okay |
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| 21:45 | is as the name implies. It's little more specific. Okay that and |
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| 21:51 | relate specialized chinese directions to Lesa genic . Right so generalized specialized lights organic |
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| 22:00 | . Okay so this is gonna look similar to the f prime formation that |
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| 22:11 | just talked to him. It was similar to that. So this involves |
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| 22:15 | landing page. Right. Which forms profile page. Right integrates into the |
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| 22:20 | and so it does so at a site. Okay and it occurs between |
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| 22:28 | galactose synthesis and biotin galactose utilization and synthesis genes in E. Coli. |
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| 22:35 | gal and bio. Okay so that's it's inserting in between there and |
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| 22:43 | Okay so what happens is again it's of these weird excisions. Right? |
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| 22:50 | when the page comes out, just they have prior information, the page |
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| 22:56 | doing one of these slightly rescue Okay. Again not common but it |
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| 23:04 | happen. Right? And so what in this case is um what do |
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| 23:11 | see? We see a um right at the gal galactose and biotin genes |
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| 23:19 | the chromosome and the galactose gene is to end up in that fage |
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| 23:26 | N. A. Okay so you it right there. Okay. And |
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| 23:34 | so if that stage then uh then infected himself informal profile page. Okay |
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| 23:44 | that next E coli may pick up additional The lactose cheap. Right? |
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| 23:50 | one has to again partial deployed checked with specialized transaction it is the transfer |
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| 23:59 | new genes relies solely on one of weird excisions. Right? Which means |
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| 24:05 | a few genes can be transferred this . Only ones in kind of this |
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| 24:11 | here or here. Okay so he's galactose and biotin on opposite science. |
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| 24:18 | one of those two already another one very close by it and that's |
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| 24:23 | Okay uh you can't transfer directly energy of the specificity of how the profile |
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| 24:30 | forms and that only in that Okay. So um that's why shouldn't |
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| 24:37 | only having you know do genes already this way? Okay. Um so |
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| 24:47 | viral intermediate. Okay. Um and finally. Okay, is transposition? |
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| 24:59 | , so transpose john's I think I before existing like I think almost every |
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| 25:06 | form has these um babies sometimes called genes. They are segments of |
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| 25:15 | N. A. Typically their normal sort of just to jump around different |
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| 25:22 | of chromosomes. Okay. But don't the idea. They're like doing this |
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| 25:26 | all the time because they're not. mean it's it's controlled to a degree |
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| 25:31 | by yourselves because you don't want that because you know, they can jump |
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| 25:36 | a spot where they shouldn't be but can on occasion um carriers they can |
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| 25:45 | to a plasma. That's one scenario than it's a contract uh X factor |
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| 25:52 | for that can then transfer me to vehicle to transfer the transpose onto another |
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| 25:56 | . But there's other mechanisms as We'll mention one here in a second |
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| 26:02 | that the process of transposition is the of the transpose. Ok. And |
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| 26:09 | these transposing these can be very very . Okay. Um That's right, |
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| 26:19 | just a transpose is g Okay. elements called insertion sequences. Right, |
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| 26:26 | sequences the neighborhood to recombine and relocate . Okay, so that's the most |
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| 26:34 | . Right? And that's in fact think it's called insertion sequences has just |
|
| 26:38 | . X cutting and splicing and that's . Okay. Um And so the |
|
| 26:46 | occurs at much like a restriction enzyme . So it creates these looks for |
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| 26:53 | inverted repeat sequences. Okay. And are characterized by this kind of a |
|
| 26:59 | . So you see A T C A T. And then here the |
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| 27:04 | sequence just inverted A T C G T right, similarly on this side |
|
| 27:10 | here as well. Right. These called inverted repeats. And it will |
|
| 27:14 | the sequence in the middle and will these kind of staggered cuts like |
|
| 27:20 | Um Now uh and so you see kind of how it happens. He |
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| 27:26 | cuts occur. So this can there's kind of ways this can be caught |
|
| 27:31 | , transferred. So very similar to Microsoft word language like cut and |
|
| 27:38 | Or copy and paste. Right? the the cut and paste is the |
|
| 27:43 | replicated form. So it it's in spot, It cuts itself out, |
|
| 27:48 | completely nothing left behind. It goes a new spot. Okay, cut |
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| 27:52 | paste, right, copy and paste when you think it is, it's |
|
| 27:56 | , that itself and then it starts and now you have cute um The |
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| 28:04 | now these can be more and more than just just being a transpose |
|
| 28:08 | And nothing else transport gene and nothing you can have then of course other |
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| 28:14 | along with these are called complex transpose . So they'll have antibiotic consistency, |
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| 28:21 | example or something else is a part it. Um And there are a |
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| 28:26 | of these in the bacterial world that antibiotic resistance. Okay. And so |
|
| 28:35 | so here's one example of how we be transferred. Okay. So you |
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| 28:40 | handle it called conservative transpo zones. . We have our donor cell right |
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| 28:49 | in the recipient. Okay. And the transportation itself can exercise and circular |
|
| 28:59 | . What you see here. You can have the elements that make |
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| 29:02 | transfer like sex pilots. And what ? Oh, and this is the |
|
| 29:08 | uh pilots is really used just has chronic connection with itself, but it |
|
| 29:14 | bring about the copying rolling circle mechanism see here transfer of DNA into the |
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| 29:21 | and then copy it. And so now the transpose john cannot exist in |
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| 29:31 | fashion, right? Doesn't exist as circle outside chromosomes. It's only in |
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| 29:37 | form to copy and transfer that It integrate that. That's the nature of |
|
| 29:43 | . They exist as integrated pieces in pros are not as outside like a |
|
| 29:50 | . All right. That's just the of transposing. Okay. Um, |
|
| 29:57 | , but an alternative mechanism could be you have a cell. Okay. |
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| 30:06 | chromosome. Okay. And here's a . Okay. So it's plausible that |
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| 30:17 | that's the chromosome that the transpose Sitting here in the chromosome. So |
|
| 30:26 | . N. It's kind of a name for transposing. So it could |
|
| 30:30 | sitting there and that could potentially jump into plasma. Right. This could |
|
| 30:37 | an F. Contain an F. factory. So I can jump jump |
|
| 30:43 | a plus plasma and then do normal with the FBI and sell. And |
|
| 30:50 | could be a way that it can that transpose on. So in the |
|
| 30:55 | cell. Okay, recipient inherits that with the transpose on it. |
|
| 31:06 | And then that could then jump into chromosome. So it's it's it's certainly |
|
| 31:13 | that could happen. Yeah. Um using the F press pass judgment as |
|
| 31:18 | vehicle transport and jumps into it and forth. Um Okay. Any |
|
| 31:29 | Okay so again just all mechanisms to segments of DNA from one to prepare |
|
| 31:36 | to another. It can be certainly closely related types that equalized and salmonella |
|
| 31:42 | whatnot. Which are very closely But certainly it's it's can be among |
|
| 31:48 | types. So um that occurred over know millennia I've mentioned national fixation. |
|
| 31:57 | a property. You see so many types of metabolically different types of |
|
| 32:02 | There can be no other explanation for that happened. Other than one of |
|
| 32:06 | . One or more of these measures horizontal gene transfer. Okay. Um |
|
| 32:13 | so let's uh so 10 part. is kind of the first part is |
|
| 32:21 | really kind of intro to regulation regulation course. And kind of some of |
|
| 32:32 | mm hmm. Find what force about . And then kind of terminology. |
|
| 32:37 | terminology we have to go through as . Okay. And then towards the |
|
| 32:42 | we'll get into the lactose Oberon. . And next week we'll we'll see |
|
| 32:47 | next week for trip to fancy opteron some other kind of things. |
|
| 32:53 | so, um, so let's start with this. Okay, so, |
|
| 33:02 | , so you have a cell here the middle and saying the internal response |
|
| 33:08 | to an output action by the set to the end formation and functioning of |
|
| 33:16 | ? Okay. Um so bacterial cells the environment, Right? Archaea cells |
|
| 33:24 | the environment, they of course are on around them and inside them internally |
|
| 33:34 | well. And so it has to a way to uh sense. |
|
| 33:40 | These, these changes. Okay. the environment and then respond to that |
|
| 33:52 | que or internal cue uh to be to do something about it. |
|
| 33:57 | Whether it's too Hey, there is dude that he may eat it or |
|
| 34:02 | condition is not good for me. need to do something about it. |
|
| 34:06 | , it ultimately comes down to Okay, So, the the same |
|
| 34:15 | in us. Okay. Same as us. Although our functions are guided |
|
| 34:20 | our outputs are typically determined by grows back. All right. |
|
| 34:34 | mm hmm. Yes. All mm hmm. It is indeed |
|
| 34:52 | Okay, proteins do the work. metal parts are be involved. But |
|
| 35:00 | know, proteins do do the do work for sure. Both of the |
|
| 35:04 | . And so um something this thing insane. Okay, so uh, |
|
| 35:13 | is so what we're talking about of is um just out of the way |
|
| 35:19 | changing expression as you as it needs . Okay, so um and so |
|
| 35:28 | changed in response to what? what you can think of a make |
|
| 35:32 | list yourself. Right. Things like , P H 02 levels nutrients Saudi |
|
| 35:38 | what it's all use inside and Um, and so that external signal |
|
| 35:45 | be quite important to a action. of course you have to have some |
|
| 35:49 | of something at the interface with selling environment on the membrane to sense these |
|
| 35:55 | . So, sensor proteins and these trigger the different types of activators we |
|
| 36:02 | them that activating expression and turn The particular genes that need to be |
|
| 36:08 | on. Okay. Again, sigma , promoters, these kind of things |
|
| 36:13 | uh and other elements and the output , you know, synthesizing a protein |
|
| 36:20 | proteins to to counteract or respond to own stimulus is okay. And so |
|
| 36:29 | control of jeans is a is a thing. Okay. And so here |
|
| 36:35 | into the terminology aspect. Okay. the levels of control. Okay, |
|
| 36:40 | put the fan Oberon expression. It can be controlled by tryptophan itself |
|
| 36:47 | one of the enzymes responsible for its . This is an example of what |
|
| 36:52 | of control. Okay, good to we'll talk about that next time but |
|
| 36:57 | uh obviously amino acid the opera um for synthesizing. It occurs the enzymes |
|
| 37:07 | Fan. Okay. Um but like operations it's controlled at multiple levels and |
|
| 37:21 | is one level of God. This is nuts. This is one |
|
| 37:27 | of control. Mhm. Yes. , mm hmm. Okay. |
|
| 38:03 | C. A. B. D. C. Is a |
|
| 38:08 | Okay. Um So who selected As in boy. So why do |
|
| 38:20 | select beat? Because it's uh proteins after. Right. So it is |
|
| 38:27 | is post translational control. So that to this. Let's study this. |
|
| 38:35 | , so multiple levels of control. right. We'll start with D. |
|
| 38:40 | . A. All right. We and these are all these can all |
|
| 38:48 | can all occur together because that doesn't doesn't just have to be one. |
|
| 38:55 | . So um D. N. . At the level of D. |
|
| 38:59 | . A. Um you can manipulate type modified nuclear types that can uh |
|
| 39:07 | heard of epa genetics right? Among and other animals genetic control. That's |
|
| 39:15 | um is modifying nucleotides to control gene . Um The we'll talk about next |
|
| 39:24 | this phenomenon of phase variation segments of . N. A. R. |
|
| 39:30 | . Recombined to prevent expression. so again level of DNA right now |
|
| 39:37 | is probably among bacteria the most Um And but the thing is it's |
|
| 39:47 | many people think transcription control has to with manipulating the transcript. Okay it's |
|
| 39:54 | that point it's think of it as you going to allow an inclination to |
|
| 40:00 | its function or not? That's what control is. So you're either preventing |
|
| 40:06 | allowing the transcript to be made that's manipulating that this transcription of control. |
|
| 40:14 | like I said it's it's a very mechanism in bacteria. Um and so |
|
| 40:20 | involved to involve the operator sequence and protein. And as we'll see okay |
|
| 40:28 | if we're if we're not talking about say post transcription control. Okay M |
|
| 40:36 | stability would be one of these Okay so because it's just right in |
|
| 40:42 | post transcription. Okay so we've made transcript now what can happen and you |
|
| 40:52 | get more and more specialized here. and um uh so our next ability |
|
| 41:00 | can affect the length of life of molecules. M. R. A |
|
| 41:06 | control is affecting the right affecting the to the translator. Not right and |
|
| 41:13 | post translational that's but the last part last step protein function. Okay and |
|
| 41:21 | um and so again operations genes can controlled in multiple ways. Okay um |
|
| 41:30 | to turn on or turn off. so um let's look at the position |
|
| 41:38 | genes. So these are always Okay so there's gonna be a seventies |
|
| 41:45 | you know typically your critical function type jeans things that always need to be |
|
| 41:51 | of growing functions that always gonna be on and sell typically uh you |
|
| 41:56 | certain metabolic pathways that cause the sole , things like that. Um these |
|
| 42:01 | typically fit into that category. so uh so next let's look at |
|
| 42:08 | some of the terminology here. So look at this question. So an |
|
| 42:13 | repressor. So a repressor. Okay. It will of course affect |
|
| 42:23 | expression of a gene. Uh but it can be manipulated in different ways |
|
| 42:29 | be active or inactive and um but active reactive enhances specific me. |
|
| 42:40 | In both states. Okay. Mhm hmm mm hmm. Alright, so |
|
| 43:41 | in fact every presser let's just say to a with this E It's a |
|
| 43:53 | . Let's see. So E is . It binds to an operator. |
|
| 43:59 | , so after oppressor, inactive So a active professor would not promote |
|
| 44:08 | activity. After request is being allowed do what it does and that's too |
|
| 44:13 | repressed means to you keep down. right, so you stop. |
|
| 44:19 | Um so it it does not does promote transcription. It wants to shut |
|
| 44:25 | off. It doesn't require an inducer . Typically is a molecule that will |
|
| 44:32 | inactivate a repressor. Okay. Um course that does not allow RNA polymerase |
|
| 44:38 | care. Dysfunction if it's in an state where president can be inactive state |
|
| 44:42 | an active state. Okay, so uh let's talk a little bit about |
|
| 44:48 | here. So refreshing active regulars, reduction de repression co repressor. Um |
|
| 44:58 | impression period just means to to limit stop too. Put a damper on |
|
| 45:05 | . Okay. Um the repression the is the opposite to take that off |
|
| 45:10 | let it allow it to function. . So um induce induction means to |
|
| 45:18 | it off. Okay, so uh just kind of a really basic uh |
|
| 45:25 | of a gene and regulatory protein. , in a sequence regulatory sequence. |
|
| 45:32 | it prepares the sequence is often a operator sequence. Okay, that binds |
|
| 45:38 | repressor of regulatory protein. And there be other examples but we'll stick with |
|
| 45:44 | . So induction de depression. I the same thing essentially. Okay, |
|
| 45:51 | we're allowing expression to occur. If we're inducing the gene were saying |
|
| 45:56 | it, right. If we're d it we're taking the repression off, |
|
| 46:01 | it to be expressed. Okay, so an induction, okay, you |
|
| 46:09 | a molecule uh so here's a repressor protein. Okay. And uh it's |
|
| 46:20 | would normally in that state, bind to the regulatory sequence. We're |
|
| 46:26 | know, we're gonna operate I think an operator sequence. Okay. And |
|
| 46:31 | but if an inducer is present and see it will agree molecule there then |
|
| 46:36 | binds to the professor. And that change shapes actually can't bind the operator |
|
| 46:42 | regulatory sequence. Right, so it off. Right, so this is |
|
| 46:48 | active state right there. This is inactive state. Right. So the |
|
| 46:54 | protein can have both states depending on conditions. And you know, the |
|
| 47:00 | inactive state will occur if that depends on the presence of inducer and |
|
| 47:06 | presence of inducer depends on something Okay, that's the that's the |
|
| 47:11 | Okay. Is what conditions allow the to be present or not? |
|
| 47:16 | if it is present, it will out this function. Okay, it's |
|
| 47:21 | present. Then the system is going be repressed. Okay, um now |
|
| 47:28 | co repressor. So repression needs to off the pressure. You can often |
|
| 47:34 | additional molecule to make it become Okay. And so in the repression |
|
| 47:43 | have repressor protein. So again, complex forms when this time the extra |
|
| 47:52 | here. Right. His binding. . We just saw the opposite situation |
|
| 47:58 | . Right molecule binds here, makes inactive. Right, molly cool, |
|
| 48:04 | there makes it act so opposite Okay, But the definition doesn't |
|
| 48:11 | An active Professor can do its And block expression interactive repressor cannot and |
|
| 48:18 | lot of expression. That's the But the conditions which make that happen |
|
| 48:23 | be completely different as you see Right. So, we'll see that |
|
| 48:30 | is essentially the Trp is short for to fan. This is a trip |
|
| 48:38 | control. Okay, this type of . This is the lack copper on |
|
| 48:45 | here. Mhm. Mhm. So inducer is not lactose. Exactly, |
|
| 48:52 | a very close cousin of lactose. . The covid presser in the bottom |
|
| 48:59 | their problems control is an actual trip itself. It's actually actually covid |
|
| 49:04 | Okay, so uh a couple of really really here is this right knowing |
|
| 49:12 | versus inactive oppressor but that's that those are the same regardless of the |
|
| 49:17 | Okay. Is the condition that allows two things can be very different. |
|
| 49:24 | . Um so many crushes about Mhm. Yeah. Um Okay now |
|
| 49:34 | layer on top of this and we about this last time the uh basic |
|
| 49:41 | expression and ramped up gene expression. , so remember basil expression simply just |
|
| 49:50 | . The only accelerates and the Okay. Very low level expression. |
|
| 49:56 | ? Not really significant. And so cell that wants to wrap up expression |
|
| 50:01 | involve other components. Okay. And here can be a formation of an |
|
| 50:06 | activator complex. Okay, so again have in this in this instance the |
|
| 50:12 | serves that purpose along with the activator . So they come together and remember |
|
| 50:18 | company promoter and that helps facilitate the of memories. You have a good |
|
| 50:24 | you have lots of expression. That's that's what that's about writing a |
|
| 50:29 | area at or near the promoter that really strong affinity for the preliminaries. |
|
| 50:36 | that promotes high level expression. And we'll see that as well in |
|
| 50:44 | right. So there was actually multiple going on to actually express the lack |
|
| 50:49 | opera and that's one of them generating activator. Okay so um so let's |
|
| 50:56 | at this question again. More context like opera on and the parts of |
|
| 51:05 | operating a little bit of terminology. . So which is true regarding black |
|
| 51:12 | . Glafkos Opera controls the metabolic pathway a synthesis of lactose in the absence |
|
| 51:18 | black. Why gene product lactose cannot detected by the cell. Black operated |
|
| 51:24 | example of post transcription control and an black professor prevents lack operation expression. |
|
| 51:36 | , let me turn. All go ahead and answer. I'm |
|
| 51:39 | I forgot to open it. So so knowing what happens in these operations |
|
| 51:55 | it's active or connected with impressive. and so we'll go through a number |
|
| 52:03 | examples exactly. You couldn't Okay lets about 5050 here trying. Uh |
|
| 52:42 | Okay so why is a wrong? you. Why is a raw not |
|
| 52:57 | it's not synthesis, it's not synthesizing yet involved in bringing it down. |
|
| 53:04 | it's a cat abolished pathway. I'm a not an anabolic pathway. Um |
|
| 53:09 | is correct. Alright. Black Is the you might call it the |
|
| 53:15 | Coast detector. Okay so we'll see that works. Okay. The black |
|
| 53:21 | example of transcription. All control. and an and an inactive lac repressor |
|
| 53:33 | will allow expression. Right. So pressure you can't do its thing. |
|
| 53:38 | that means j expression occurs. Um Alright, so with black Opera |
|
| 53:45 | , the one thing you don't have worry about is this gene and gene |
|
| 53:52 | . Okay. Z. Y. only want to focus on uh to |
|
| 53:57 | day, there's really not know what lack a even does, right? |
|
| 54:03 | e coli Elizabeth, there's a black oak fermenter. So you can have |
|
| 54:09 | lack a lack a mutation and it affect the ability to use lacquers. |
|
| 54:14 | go figure catch. Anyway, so Z. And why are the keys |
|
| 54:19 | ? So um so that's a typical has its own promoter promoter but then |
|
| 54:27 | has a black eye, that's the protein, the repressor. Okay. |
|
| 54:34 | so interacts with the operator sequence of lactose opera. And so Step one |
|
| 54:42 | , there's always this basil expression of black jeans. So remember basic expression |
|
| 54:50 | really low. Okay, and so going, well why is it doing |
|
| 54:56 | ? It's not even if there's no around, it will still be expressing |
|
| 55:01 | level. Okay, and you think why should it be doing that? |
|
| 55:05 | . It goes backward into the question just had because we have to make |
|
| 55:09 | little bit of the lack of um black um y product. Okay, |
|
| 55:18 | they see that permeates permeates as a protein, it binds and brings flag |
|
| 55:24 | in. So with that synthesizing a bit of that and let me a |
|
| 55:32 | we're talking like maybe two bathrooms, to lack white modules maybe are |
|
| 55:38 | And that's how you can see they're holes out there. Okay. If |
|
| 55:43 | is it will bring it in. . So the paths the genes involved |
|
| 55:49 | this pathway against catalog metabolism metabolic And so lactose is a dissect |
|
| 55:57 | Okay. And the lack Z product sides but black societies cleans that and |
|
| 56:05 | kind of begins the process of how enters black analysis. Right? So |
|
| 56:10 | it down. But it also has other side reaction which is the production |
|
| 56:15 | Kalama lactose. Okay. And this what actually actively. Okay, so |
|
| 56:22 | and glucose are the products of when cleave lactose. Right? And this |
|
| 56:26 | in on into metabolism. Right, six phosphate lactose has another reaction funnels |
|
| 56:35 | um black causes. Right? So lot of those into black causes so |
|
| 56:39 | . Okay. Um and so uh going back to this, the role |
|
| 56:47 | why you have such a white you a low level again, super low |
|
| 56:51 | of expression is for the purpose of the lack. Why? So it |
|
| 56:58 | sit in the membrane and look out lactose if it's present. Okay. |
|
| 57:04 | so um we express again at a level. Okay, these jeans and |
|
| 57:11 | the lack y okay. So if lactose is present. Okay, it |
|
| 57:17 | bind. Right? And then you some black wire there as well. |
|
| 57:22 | sea bag like the size. And that can convert some of that to |
|
| 57:27 | lactose and then shut off inactivate the . And then we get then we |
|
| 57:35 | really wrap up if there's lots of out there then very quickly it will |
|
| 57:41 | from basal expression too, 1000 times expression right? The high level expression |
|
| 57:47 | you, glucose. So um and again the uh when I save a |
|
| 58:01 | bit of personal I mean yes, a little bit of answer to do |
|
| 58:05 | . We're going to really love like a couple of molecules work. So |
|
| 58:09 | not a lot of energy expenditure do but it's necessary otherwise it's going to |
|
| 58:14 | able to see lactose at all. um so we have under control. |
|
| 58:22 | in the absence of lactose of course a full so it actually occurs by |
|
| 58:30 | te trimmer of this repressor forming for coming together and help to they bind |
|
| 58:39 | the lack i operator and the lac operator. Alright bring it together to |
|
| 58:46 | this kind of loop right previously. these come together as you see here |
|
| 58:56 | this loop that acts like an army memories. Can't buy. So it |
|
| 59:00 | it can't do its thing. So transcriptions blocked. Okay whereas the presence |
|
| 59:05 | inducer then they buy into the uh and then in that state the repression |
|
| 59:12 | buy into the operator and you get . So again um um high level |
|
| 59:18 | can occur once we have the presence black toast there. So your oppressor |
|
| 59:24 | , depressed are inactive now. Um layer occurs on top. So it's |
|
| 59:32 | of your basic level of depression then more to it. And that's kind |
|
| 59:36 | what this question is asking about. , mm hmm. Okay. |
|
| 60:24 | Okay. Alright, so we get C. That is correct. |
|
| 61:10 | so and actually involves this and Okay, so those two come together |
|
| 61:23 | form a an activator complex. so this is the black opera also |
|
| 61:29 | that in addition to obviously you have presence of black toast comes in and |
|
| 61:35 | the el Acto. Some of it the allies lactose. That's the |
|
| 61:39 | Right, so um the um absence glucose is the other thing. |
|
| 61:48 | so the glucose is the primary source present. Okay. Uh for a |
|
| 61:56 | of reasons, probably one of the ones is um Mhm. We just |
|
| 62:03 | lactose. Right? So it is the process for black houses. |
|
| 62:09 | It's a couple of extra steps to that. Okay, glucose doesn't require |
|
| 62:14 | if you come in this cell as as for later than boom. Right |
|
| 62:18 | black causes. Okay, so much efficient source compared to these other |
|
| 62:23 | All the other sugars inside glucose and these 30 or 40 different types of |
|
| 62:30 | . Okay. Can you can metabolize tose um Ram knows lots of |
|
| 62:38 | Okay. Can it ferment sucrose, in lab? It is. You |
|
| 62:46 | to Ronnie Coleman? You can't Yeah. Um It can do glucose |
|
| 62:56 | lactose but not super close. Um at that point so glucose is much |
|
| 63:03 | efficient source. Okay. And so tends to be the big dog. |
|
| 63:08 | it's if it's if it's around with sugars, it gets used first. |
|
| 63:13 | . So how does it do Well, it doesn't because of the |
|
| 63:18 | GMP crp mechanism in fact. But the 2nd 2nd piece is a it's |
|
| 63:26 | universal mafia. Lots of all life have it is typically used in the |
|
| 63:32 | of cell cell signaling. Really. . Um here it's used As as |
|
| 63:41 | help activation but it's levels can 2nd. levels in bacterial cell fluctuate |
|
| 63:48 | on the presence of of glucose. , so um the levels are high |
|
| 63:57 | levels lower cyclic GMP lovers. Okay and so second A Mp is |
|
| 64:06 | so you have these three forms a . Okay. You have A |
|
| 64:13 | P. And you have A. . P. Okay. And so |
|
| 64:19 | levels of those kind of be an of the energy state of itself. |
|
| 64:25 | . And um A. And P course is used to make cyclic GMP |
|
| 64:29 | that's kind of how it ties into mechanism. Okay. Um So lots |
|
| 64:37 | glucose around means um you have a energy level. Lots of you |
|
| 64:42 | ADP ADP molecules and less of a mp glucose levels go down right? |
|
| 64:50 | second hand clothes go up indicate who got to get something else to get |
|
| 64:54 | with. Okay. And that's when you'll mobilize these other sugar using operations |
|
| 65:01 | to see over there's this stuff out if it is. Let's use |
|
| 65:05 | Okay, because we don't have any . Right? So that's when that |
|
| 65:09 | of overtakes it. And so so all about um the levels of cyclic |
|
| 65:17 | . And so if they're high, would be the case with the lower |
|
| 65:21 | around. Right then there's plenty of to bind this crp protein. It's |
|
| 65:28 | the GMP. So those two come . Right? So the second cRP |
|
| 65:33 | which binds like a GMP is kind around, you know, at at |
|
| 65:37 | particular level. But the second GMP what fluctuates Okay, so the second |
|
| 65:43 | levels are high then you'll promote this complex that will increased expression. |
|
| 65:53 | And so that's what you want to because of glucose. But you have |
|
| 65:56 | other sugars around. Okay. And the converse happens if you have then |
|
| 66:03 | won't have this accurate complex and you get expression of the black chakra, |
|
| 66:08 | you wouldn't want a tow glucose goes . Okay, So when you have |
|
| 66:15 | you do have the active complex, would be the case in absence of |
|
| 66:20 | presence of lactose, you then promote level expression. Okay, so |
|
| 66:26 | I love the expression have black toast . Don't have group posts around and |
|
| 66:33 | will give you that high level expression the black opera on. So um |
|
| 66:41 | this tablet repression is called um so repressing. You can think of black |
|
| 66:47 | as a metabolite. Right? Lots monsters are metabolites that are broken down |
|
| 66:51 | metabolism. Okay, so glucose access press these other metabolites. Hence the |
|
| 66:57 | . Okay, so if you have both, of course in the same |
|
| 67:02 | medium. Okay, um this is kind of growth pattern you see in |
|
| 67:07 | of monitoring glucose and lactose levels. , so uh glucose levels go down |
|
| 67:16 | and then lactose also in terms of GMP. Alright, so C AMP |
|
| 67:24 | love but then increases and it goes as glucose goes away. Okay, |
|
| 67:33 | then that promotes lactose utilization. So be a little because he's just used |
|
| 67:38 | . Okay then we have that plateau and this represents oop. We're kicking |
|
| 67:44 | those jeans now and now we can things up again. Ok, and |
|
| 67:52 | from a molecular standpoint that looks something this. Okay, so glucose um |
|
| 67:59 | , we've seen this before, that supportive mechanism Back in Chapter three. |
|
| 68:06 | glucose comes in and immediately modified phosphoric six phosphate. Right, so these |
|
| 68:12 | groups are hanging on to the substance the transporter. Okay, In this |
|
| 68:19 | phosphoric state, This particular component. interferes with black. Why? Okay |
|
| 68:27 | does not allow lactose to come Okay. We call uh inducer exclusion |
|
| 68:35 | this being not exactly inducer but at the making of the inducer. But |
|
| 68:39 | called exclusion can't come in because of state of that interference by this |
|
| 68:47 | And so glucose is absent. Okay these phosphate groups are staying on here |
|
| 68:54 | there's nothing to there's no glucose to it to. So they stay in |
|
| 68:58 | state and in that state they don't with the black white functions, |
|
| 69:05 | So um uh and so also the of glucose means you're cycling GMP levels |
|
| 69:12 | high. And so that promotes transcription black opera. Okay so um so |
|
| 69:19 | opera. Right? So how black present? Absent. That scenario means |
|
| 69:26 | have um the presence of inducer. means you have high second mp |
|
| 69:33 | It means um you get active You have an inactive repressor in those |
|
| 69:40 | . Okay so think of that those those things you're looking at the |
|
| 69:45 | Okay. What happens when it's active and when it's not expressing what what's |
|
| 69:51 | on with these various components like I mentioned? So have you know be |
|
| 69:56 | with that? The other thing uh gonna stop here in a second. |
|
| 70:01 | look at the animations um 40s that posted both for lack of opera. |
|
| 70:07 | a different. I think they're very and looking at it. I'll show |
|
| 70:13 | next week. But uh look at pictures plus the text that comes with |
|
| 70:18 | . I think you'll find it Right? But you want to be |
|
| 70:22 | to contrast not we haven't talked about yet but be able to look at |
|
| 70:27 | lactose restricted to an opera and contrast two things. So um animations helped |
|
| 70:33 | great deal with. So that's it . The weekend? I'll see you |
|
| 70:39 | Tuesday. Yeah, they are all , laughter offered every semester. |
|
| 71:08 | Because I was looking for Oh, must be it must be ok. |
|
| 71:36 | . Ok. Ok. Yeah, should show up. I mean I |
|
| 71:40 | double check but I know it's Yeah, that's smart. What is |
|
| 72:14 | what? I don't know. It to me that I mean sometimes it's |
|
| 72:20 | a random thing but I know that not um it's controlled to a degree |
|
| 72:29 | you can't have that occurring all the . So there are mechanisms that that |
|
| 72:33 | cell can do to minimize the degree that. I understand it's somewhat of |
|
| 72:42 | a random process where they look Like I don't think they do because |
|
| 72:49 | think you can you can uh from human standpoint we can kind of control |
|
| 72:54 | of these things. I don't I think because of the system with |
|
| 73:07 | become so well known. We have many tools for that. That's kind |
|
| 73:12 | the way to go. But I'm saying that people don't use and I'm |
|
| 73:16 | they do. Yeah. For for specific types of transfer had a black |
|
| 73:24 | . Yeah. How do you I explain if we need cereal with milk |
|
| 73:30 | processing and capitalizing on first and then this after. Yeah. Absolutely. |
|
| 73:36 | . It's all about what's going on the in the cell certainly. But |
|
| 73:41 | , that's that will take place. same kind of mechanism will take |
|
| 73:44 | You have both at once. We won first in the next one. |
|
| 73:55 | . What's that? Had a hard . Which ones for? Yeah, |
|
| 74:03 | the final plan. Lieutenant in the to incorporate that means inventory actually |
|
| 74:13 | incorporate the reduced metal into their Oh, went outside the cell then |
|
| 74:20 | would be this simulation. Right? went on the test. I thought |
|
| 74:25 | knew a lot more than a Yeah. Yeah. Yeah. So |
|
| 74:37 | asked me if equal, I can secrets question correct? So that they |
|
| 74:44 | that can be strong. I restrained land. But okay. I'm pretty |
|
| 74:49 | I remembered equally being able to like for gas production and fermentation. Like |
|
| 74:55 | was yellow and gas production and they did. It wouldn't be for |
|
| 75:05 | it wouldn't be for that. There be other there can be variations for |
|
| 75:11 | strains and species and it kind of a You will sometimes see in uh |
|
| 75:17 | these tables of these tests that 87% strange tests that show positive. But |
|
| 75:24 | you only said that maybe 10% or . It varies from strange strange but |
|
| 75:27 | can have some variations like that. your point was basically that I mean |
|
| 75:31 | whole semester you've been able you were about how bacterias can turn on and |
|
| 75:36 | genes and that's pretty much what we're about. Yeah. Yeah. |
|
| 75:42 | Yeah I have another question. Um So can you explain more about |
|
| 75:48 | high uh C. M. Uh have to do is really with just |
|
| 75:57 | things I guess fluctuating the the exclusion lactose into the cell. That mechanism |
|
| 76:04 | the fluctuation of psychic GMP levels. glucose will uh is a is going |
|
| 76:14 | be the preferred carbon source. So lots of glucose around lots of challenges |
|
| 76:20 | on. And um it's more like ghost runs out. Is there another |
|
| 76:26 | of. So it's like the MPX of somewhat like an energy indicator in |
|
| 76:31 | . So if if it's kind of it's almost like a signal knowledge going |
|
| 76:38 | . So the levels of the Angelos sell articulate through A T. |
|
| 76:43 | A. D. P. So if it becomes racial typically of |
|
| 76:49 | 1.5 is what a healthy cell. if that begins to drop which can |
|
| 76:58 | if you know the ones out it low the sauces from some other sources |
|
| 77:04 | the energy level the number of drops racial drops. And then I think |
|
| 77:09 | of that 80 P ADP gets converted a Mp. Which is actually the |
|
| 77:15 | . And that's kind of how so think the second mp is an offshoot |
|
| 77:21 | mm hmm, fluctuations can be produced a so but I think that can |
|
| 77:36 | if the trickery is that ratio and it becomes energy. Then you get |
|
| 77:46 | . Yeah. Yeah. Yeah. . That's how it kind of ties |
|
| 77:53 | . Yeah. Yeah. I looked up in C. A. |
|
| 77:57 | P. Is a cyclic. right, right, right, |
|
| 78:03 | Yeah. I was thinking okay. there's a lot of Hi I am |
|
| 78:15 | I wanted to ask when he basically like no 80p people are not easily |
|
| 78:19 | . It. It's just not very alright. You too. We'll see |
|
| 78:31 | say yes, mm hmm. mm |
|
