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00:00 Oh yeah. Okay. Yeah Right. Hey folks. Uh

01:15 Uh Let's see. So today um on with chapter nine finish up chapter

01:27 1. Remember that flip class? a bunch a bunch more questions.

01:33 I think we'll get through at least . Um But the so remember the

01:43 dates for these things and then the mentioned last time about midterm grade.

01:48 so I'm in the process of almost that so you'll be able to see

01:52 tomorrow sometime tomorrow. So uh late , early afternoon. Um So it's

02:01 um it's uh it's like regular. um The extra credits included in

02:13 Okay even though as a credit for out the evaluation, even though you

02:17 done it yet obviously. So that's all figured. Okay Um so um

02:23 points 3-23rd. Okay. Not to 23rd and first the is inquisitive And

02:37 12 so all that and so it's a it's very accurate estimate. Okay

02:46 I mean it's something that you can use that value as a way to

02:50 you know what you need to do get where you want or whether you're

02:57 um uh what was the other thing was um But kind of details of

03:14 the of the calculation but anyway so have that information which I'm sure you

03:21 . So um I think that was my hand about that stuff. Any

03:30 about anything. No. Alright. so let's um move ahead. This

03:39 I just kind of put this stuff we've been talking about in Chapter nine

03:44 from last time. So, it's of Put this in perspective I

03:51 So we're looking at uh we looked in 78 the Terrio genome gene

04:01 Right. Um Kind of building toward couple of things. One the checking

04:08 kind of covers this is how Coqueiro can introduce variation into the population.

04:15 , sure. They can reproduce by fission. Alright, that vertical gene

04:21 allows them to pass genes to the generation. Then they also have this

04:25 to receive transfer genes from other members the population. Right? Um Transfer

04:35 we've uh just you know, sunrise that upper right figure there uh production

04:44 . Right. So um since book can't reproduce sexually. Right. Which

04:52 introduce a lot of variation as has with us and other imperials. They

04:57 have this ability to exchange and transfer which again introduces variations of population.

05:07 So we covered transformation and are going congregational. All right. So,

05:15 know, the kind of things are to students. Genomic islands.

05:18 So these are like transferable region. You kind of need to be transferred

05:26 a plasma uh are of a similar . Of course. Right. But

05:32 it's a disease causing mechanisms pathogenesis. islands transferred virulence factors like a capsule

05:41 these kind of things toxins. Somebody islands, particular components involved in setting

05:46 the the bacterian interaction uh typically pathways can give them uh an advantage on

05:55 certain conditions. So anyway a couple things. The importance of recombination.

06:02 already seen that the combination is how an acquired segment of D.

06:09 A. Can become part of its by combining with the chromosome check.

06:16 Sorry thank you. Kind of touches everything. So we'll go through

06:21 we'll finish conjugation with the transaction Let me just show you this a

06:27 of animations here. Okay so this the F. Factor conjugation. So

06:35 the what we have is a room have many pairs A we have a

06:43 factor factor is the portion of that . So we're transferring plasma is here

06:50 that contains the genes that enable trans . So sex pilots uh the component

06:58 kind of helps bridge themselves together so kind of components that facilitate the

07:03 Okay and so uh that uh then with an F. My cell.

07:10 so we see here the process let's flip this forward here. Okay so

07:17 it begins with the extension of a pilot, assist religious politicization of that

07:23 to lengthen it. You see the and the factor in the in the

07:30 cell that we have. Just kind slow. Okay let's speed it up

07:36 little bit there we go here comes recipient cell contact with it and then

07:43 have subsequent depressurization to decrease. That's much stronger connection, stable connection.

07:52 then um mobilized the uh classify said . What we're talking about is properly

07:58 . Moving it, moving a copy the recipient in china. And so

08:04 so that's going on. And so can have uh transfer. Then the

08:08 circle replication mechanism, right kicks And so now we have an f

08:14 has become an F plus set. . And so as you watch

08:21 something something's happened, what happened to X plus cell? What kind of

08:25 did acquire that didn't look bald And then all of a sudden grew

08:32 after the connection. Right hair Right? Probably embryonic gene. Some

08:38 that inherited because the point being, it inherits, of course potentially express

08:45 in this case. Uh It was some kind of of. Right?

08:52 um so that's your basic F plus minus congregation. The f minus

08:58 Recipient becomes an F. Plus. let's look at the HFR.

09:05 let's go back to hear this. uh here. Okay, so here's

09:14 H. F. R. pause that um and so integral plasma

09:21 into the chromosome. Like So so got yeah, so now we have

09:27 course the chromosome with the integrated Right, so now the plasma cell

09:31 still left plus, it's just the is in been integrated into the

09:36 So what that means though is the chromosome can become mobilized now.

09:43 So uh so we're gonna see that . And it sort of makes with

09:48 f minus cell here it comes. the same process uh they come together

09:57 then So now instead of transferring the that were carrying out copying of the

10:04 now the thing to remember is that is the part back here that contains

10:12 transfer genes. That this is essentially makes it have plus. Okay.

10:18 you know, this is the part gonna if if it were to

10:22 this would be the very last That would probably get transferred to the

10:25 cell. Right? But we're going see that that doesn't happen.

10:29 So we see the dropping. So it is. So they don't stay

10:34 enough together for that part could be . That's why this f minus stays

10:40 an f minus. Okay, you to be together for a long time

10:44 this to occur. And you see the uh back up a set,

10:53 now this anonymous DNA is eric if combined, All right, it would

10:59 to this would have a very probably lifetime would try to cool exist as

11:04 piece of DNA. So to to make a more permanent part of the

11:09 . Uh it has to recombine. ? And so that of course means

11:14 has to be some level of similarity between you two because it's all about

11:22 , the documentary base pairing. so now we have that minors

11:25 States of mind because they did not not able to inherit that last bid

11:30 is the transfer the F. Plus that enable it to be transferred.

11:35 um So It crushes by the 18th . Okay so I'll summarize here on

11:43 next slide. Just go to Uh He here. Okay so uh

11:51 what we just that's the first We saw that this basic F.

11:55 F minus congregation. Um The I this picture can be a little bit

12:04 because you're seeing it from minus cell the plasma already in but it initially

12:09 have it of course that inherits the and then that returns mixing F plus

12:15 HFR. Again the integrated class read to an F minus cell. But

12:22 minus typically stays as F minus. then we have another another process.

12:32 that um is what we call the . Prime factor. So very quickly

12:38 then when you see that, when ask the question first, before you

12:42 that. So uh the formation of prime factor required what I think you

12:49 know one of those already. Haven't that picture. Every crime factors.

12:55 this has to do with them. if the plasma can integrate the chromosome

13:05 then it can come out as well it kind of relates to that

13:09 Okay. Mhm. Open the reset sorry? Okay wow. Okay Here

13:55 go. Yeah. And to our are ahh ahh Marcel and excision two

14:20 . C. And E. So what this is about as I

14:27 , HFR size integrated plasma. So can also exercise. I'm not in

14:34 nature of our cell. I'm not the frequency of you know how often

14:40 comes out. Okay. But if does come out then what does exercise

14:46 means to come out exercise out of pro zone, vast majority of

14:57 But when it is what comes So but that doesn't mean here in

15:01 . Right? The integrated F Right? This is a plasmid that

15:05 in all purple color. Okay, in a normal excision, that's what

15:11 out. Ok. But an Prime factor results when that cutting,

15:18 to speak. Think of two scissors are cutting right? That those scissors

15:25 left or right slightly. Okay, in this case we're moving slightly to

15:31 right. So that what we're what's being cut out. Is this?

15:39 , that's what comes out that happens as a frequency. They're one in

15:42 million times it happens like this. other most of the time is

15:50 Right? So what happens is this in this example the B.

15:57 B genes there will be jean stupid . A lot. Okay. The

16:10 gene will kill you. Let's try . Yes. Victory. Okay.

16:26 The B gene which is on the and catholic was part of the chromosome

16:30 now it's coming out with that B . So probably should stay behind but

16:34 not because of the excision. So that becomes part of the

16:41 But then also then this part of plasmid stays behind, Right? So

16:48 stays behind and a new part goes it. All right. So that's

16:51 you see here as it is. recombination occurs right? Here is the

16:57 B gene. Right. And then the end result is we have a

17:04 . So we call it F prime it when it when this kind of

17:07 occurs where his words picking up this from the chromosome. But then I

17:13 remember that part of it's left Okay, so that's the F

17:18 And so what's the big deal about ? Well, the big deal can

17:22 if it congregates this. This cell with another member of the population.

17:27 same population then you might generate what's a partial difficult. Okay, so

17:35 we are all full deployed. Um heard of genes from both mother and

17:43 but apart from deployed only hands, know, less than that. Of

17:47 . Right. And so uh so actually be jean uh and so that

17:55 be a benefit that that be gene evolve independently. So whatever the the

18:03 is, um it can still do function but then this extra one can

18:10 know, as I said we evolved . Maybe it acquires a mutation or

18:15 . Maybe enabling a slightly different activity be benefits to sell. But um

18:22 maybe it had a bad uh nonfunctioning BG. And now baby inherits a

18:30 version. And you can then then you don't realize that pathway. So

18:35 different benefits from being a partial did like this. Okay. Um very

18:43 about. Okay so here again is summary of all three of these

18:49 This is the last one we just about. Okay so the age of

18:52 cell uh and the kind of strange that occurs to generate potentially crime.

19:00 mean prime potentially a part of the . Okay so um all right so

19:10 is trans deduction. Right so we transformation propagation not transaction. This is

19:18 our virus. Okay so we've gone viruses already. So um generalized

19:25 Think of a lightweight fage. Political page would go through a cycle

19:33 this. Okay uh genome entry began the genome, viral replication of viral

19:42 etcetera and um breakdown of the host occurs as part of the cycle.

19:50 then what happens is an error in occurs. So the viruses packaging viral

19:55 and the caps it and then by packages host D. N.

19:59 Instead. Okay so now we've got particles containing host D. N.

20:07 . Okay so the cell virus kills cell virus breakout and then um they

20:15 another set. So any host cells infected by? Hey hey virus fage

20:25 host DNA. This guy. Okay of course it's not going to kill

20:31 cell because it's not carrying the viral . So but what can happen is

20:37 it's the portable mechanism of getting the hosting into that cell. Okay and

20:46 uh the combination would have to occur course to allow that fragment to be

20:52 to survive. But it nonetheless is up jeans right from that previous host

21:01 . Right um and so uh and thing about generalized transaction is potentially any

21:14 gene in this previous host Any any these fragments can be incorrectly packaged in

21:22 virus which means potentially any gene can transferred this way. Okay that's in

21:30 to specialized transaction. We'll talk about in a second. So here theoretically

21:36 previous prior hosting can be transfers. . Um So specialized transaction. Okay

21:45 is as the name implies. It's little more specific. Okay that and

21:51 relate specialized chinese directions to Lesa genic . Right so generalized specialized lights organic

22:00 . Okay so this is gonna look similar to the f prime formation that

22:11 just talked to him. It was similar to that. So this involves

22:15 landing page. Right. Which forms profile page. Right integrates into the

22:20 and so it does so at a site. Okay and it occurs between

22:28 galactose synthesis and biotin galactose utilization and synthesis genes in E. Coli.

22:35 gal and bio. Okay so that's it's inserting in between there and

22:43 Okay so what happens is again it's of these weird excisions. Right?

22:50 when the page comes out, just they have prior information, the page

22:56 doing one of these slightly rescue Okay. Again not common but it

23:04 happen. Right? And so what in this case is um what do

23:11 see? We see a um right at the gal galactose and biotin genes

23:19 the chromosome and the galactose gene is to end up in that fage

23:26 N. A. Okay so you it right there. Okay. And

23:34 so if that stage then uh then infected himself informal profile page. Okay

23:44 that next E coli may pick up additional The lactose cheap. Right?

23:50 one has to again partial deployed checked with specialized transaction it is the transfer

23:59 new genes relies solely on one of weird excisions. Right? Which means

24:05 a few genes can be transferred this . Only ones in kind of this

24:11 here or here. Okay so he's galactose and biotin on opposite science.

24:18 one of those two already another one very close by it and that's

24:23 Okay uh you can't transfer directly energy of the specificity of how the profile

24:30 forms and that only in that Okay. So um that's why shouldn't

24:37 only having you know do genes already this way? Okay. Um so

24:47 viral intermediate. Okay. Um and finally. Okay, is transposition?

24:59 , so transpose john's I think I before existing like I think almost every

25:06 form has these um babies sometimes called genes. They are segments of

25:15 N. A. Typically their normal sort of just to jump around different

25:22 of chromosomes. Okay. But don't the idea. They're like doing this

25:26 all the time because they're not. mean it's it's controlled to a degree

25:31 by yourselves because you don't want that because you know, they can jump

25:36 a spot where they shouldn't be but can on occasion um carriers they can

25:45 to a plasma. That's one scenario than it's a contract uh X factor

25:52 for that can then transfer me to vehicle to transfer the transpose onto another

25:56 . But there's other mechanisms as We'll mention one here in a second

26:02 that the process of transposition is the of the transpose. Ok. And

26:09 these transposing these can be very very . Okay. Um That's right,

26:19 just a transpose is g Okay. elements called insertion sequences. Right,

26:26 sequences the neighborhood to recombine and relocate . Okay, so that's the most

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

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

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

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

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

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

28:14 along with these are called complex transpose . So they'll have antibiotic consistency,

28:21 example or something else is a part it. Um And there are a

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

28:40 handle it called conservative transpo zones. . We have our donor cell right

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

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

29:21 and then copy it. And so now the transpose john cannot exist in

29:31 fashion, right? Doesn't exist as circle outside chromosomes. It's only in

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.

30:06 chromosome. Okay. And here's a . Okay. So it's plausible that

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

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