| 00:01 | Okay. All right so um we going to go through, I've got |
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| 00:15 | in the last couple of hours I notified and I have to go to |
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| 00:18 | committee meeting. So we're gonna go . So it's good news, bad |
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| 00:23 | , bad news would be expected to in here and here. My golden |
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| 00:26 | for an hour and 20 minutes. news. No I didn't um any |
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| 00:34 | . Um So we're gonna go through gonna go through all depend on, |
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| 00:43 | that's what we can and so the part will have will be what we |
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| 00:47 | other control mechanisms, stranger response, factor regulations etcetera. That will do |
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| 00:53 | thursday. Okay so get up through of the trip to find out from |
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| 01:00 | we'll also mentioned really has something back up on stuff like that. A |
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| 01:04 | of animations then we are done. um so this week uh you know |
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| 01:11 | . Okay remember that's one of those longer kind of things. A little |
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| 01:15 | comprehensive. So that will be up smart work kind of a little |
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| 01:21 | Chapter 19 Sunday, two days Chapter 10. Okay. Uh of |
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| 01:27 | the exam is later next week. . Um Oh and I posted and |
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| 01:34 | sent a lengthy email somewhat on that yesterday about the midterm grade. So |
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| 01:40 | read that if you haven't seen seen email, read it gives you a |
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| 01:44 | by blow details of how that thing calculated. Just just refer to the |
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| 01:48 | , exactly how it's done. Okay The quicker grade for the midterm I |
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| 01:55 | go to the exercise because I don't spend that much time capital, everybody's |
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| 02:00 | and all that stuff. So I said okay the grade for the mid |
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| 02:05 | grade for the midterm grade was quicker . You got divided by the number |
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| 02:09 | sessions you attended. That's it. so. Okay so um so yeah |
|
| 02:20 | can't and you have one more exam uh before you before you decide what |
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| 02:29 | gonna drop or not, you're going get another third exam that you can |
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| 02:33 | there into that grade. The email tells you how to do that. |
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| 02:37 | so bottom line read the email that yesterday that gives you the detailed |
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| 02:43 | Okay. Um Alright so let's go the whoa there we go. So |
|
| 02:54 | kind of rehashing stuff we've been talking last month. Overriding theme here of |
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| 03:01 | is regulation gene regulation Makarios. Um to this we looked at like the |
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| 03:08 | in structure again of bacteria uh things few other things about um the regular |
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| 03:17 | the plasmids and stuff. And then time the congregation and transformation and trans |
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| 03:25 | and transposition. So all these mechanisms horrible technology transfer. Now we're zeroed |
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| 03:30 | on the actual control mechanisms. Talking kind of overview fashion initially. So |
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| 03:39 | remembering the uh the levels at which control expression of course going to be |
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| 03:48 | where how how it occurs. So many of these points along the |
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| 03:52 | whether it's DNA itself um can manipulate of D. N. A. |
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| 03:57 | nucleotides and effective expression. You can manipulate the our next limericks. We're |
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| 04:05 | let it transcribing not transcribing. You manipulate the transcript that's me alter the |
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| 04:12 | of it. You can alter Mess, mess with the riders on |
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| 04:16 | , you can alter proteins, you modify them, you can just you |
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| 04:20 | just degrade them. Any of those of these steps will lead to uh |
|
| 04:26 | gene expression obviously. Okay and so we went to different types of terminology |
|
| 04:31 | conduction, repression, repression, co active after repressor. So remember that |
|
| 04:39 | it is um this definition does not . Right? What changes is one |
|
| 04:47 | the conditions which bring each of these about. Right. So as we'll |
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| 04:52 | lactose and it really in a nutshell this diagram I looked at the top |
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| 04:56 | here is actually how lactose opera operates terms of control. The bottom part |
|
| 05:01 | how the different opera operates. Okay it's all about repressors interacting with regulatory |
|
| 05:09 | and are examples. We'll look at sequence. Okay. And uh the |
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| 05:15 | which make it active. Okay. be the absence of a special molecule |
|
| 05:22 | this case. The inducer when it's present, professors active. Okay, |
|
| 05:27 | of inducer in activates the repressor. uh so the inducer then promotes |
|
| 05:35 | Okay Oxford situation down here. refreshing occurring by the presence of the |
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| 05:42 | pressure. So now the molecule binds the pressure. Now they're pressured |
|
| 05:46 | Right, completely opposite of what's going up here. And so uh this |
|
| 05:50 | how the trip to find corporal We'll talk about in a second. |
|
| 05:54 | , so um do be familiar or with these terms. Okay. And |
|
| 06:00 | they mean then last week we went the almost there. So so remember |
|
| 06:06 | can also have uh activators and repressors once you try to stop expression but |
|
| 06:11 | have activators that actively increase expression. . And we saw that with the |
|
| 06:18 | opera on as shown here. So we went through what happens when |
|
| 06:24 | so overriding thing. The opera is about is a cattle bolic apple |
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| 06:30 | It's about the components of the outrun proteins that are that are coded for |
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| 06:37 | the opportunity to metabolize license, begin breaking it down. And so again |
|
| 06:47 | the lack of itself technically is will the inducer to buying professor locking |
|
| 06:58 | Yeah, That's step one. This happens in the presence of black |
|
| 07:03 | absence of glucose, glucose has that influence uh if they preferred carbohydrate sources |
|
| 07:13 | . Um and it will override anything of me resource. And so the |
|
| 07:18 | gone and that and that and that with glucose and cyclic GMP. |
|
| 07:25 | Just like a GMP levels rob glucose around but then the glucose goes |
|
| 07:33 | It's like a GMP levels rise and of promoters. Many different types of |
|
| 07:40 | . Others should be utilizing operations are the same control. And so second |
|
| 07:47 | rises that combine the separate protein and becomes an active complex. So remember |
|
| 07:54 | increased the expression means to let's put on the promoter to let you allow |
|
| 08:02 | really tightly bind. Right, make very attractive for our preliminaries to come |
|
| 08:08 | the promoter and generate lots of Right? So that's what that's what |
|
| 08:13 | do they collect at the promoter um provoke, right, high level |
|
| 08:20 | Which equates to last expression. So not just not just uh in |
|
| 08:25 | example, but if you look at and look at other types of eukaryotic |
|
| 08:30 | expression, the same thing. Budget come together at the at the promoter |
|
| 08:35 | bring about high level expression. Um I kind of went through in |
|
| 08:42 | hurry but we went through this last . There any questions about. |
|
| 08:47 | so let's look at um Okay, just do this now real quick. |
|
| 08:53 | look at the animations which are available you as well. Okay. And |
|
| 08:59 | have the option of you can put text on as well to see kind |
|
| 09:06 | the transcript. But nonetheless, so is uh our bacterium hearing black opera |
|
| 09:14 | the different genes of the operas from . Y. A. We don't |
|
| 09:18 | about A. Because that that protein not really involved. The lactose up |
|
| 09:23 | or breakdown. So you don't need worry about it. Remember the lactose |
|
| 09:28 | ? That's the black Y. That's that that has to be. |
|
| 09:32 | remember there's a little little bit tiny of expression always occurring. Okay. |
|
| 09:39 | um the with lactose permeates is the . We have to make a little |
|
| 09:49 | of expression to produce one or two were with black clothes permit. He's |
|
| 09:54 | . So now if it's present in blue dot that's glucose. But if |
|
| 09:59 | is present, potentially it can bring in. Okay. And so um |
|
| 10:06 | move forward a little bit here. so there's opponents. Again, the |
|
| 10:17 | presser is here according to the rough protein. Okay. And uh back |
|
| 10:25 | a sec here. So remember that control the control is this repressor will |
|
| 10:32 | to the operator. Okay. Unless present and the blue coast is |
|
| 10:42 | And so the binding of the repressor combines the lack opera operator and the |
|
| 10:50 | I operator forming this kind of And and that's something that covers up |
|
| 10:56 | promoter promoters cover. So memories can't do anything. So it's kind of |
|
| 11:01 | goes like that can't buy and can't . So essentially it's blocked. |
|
| 11:08 | So we know that in the presence of that win. Um The instances |
|
| 11:16 | which. Mhm. Let's see if show that here at the last |
|
| 11:24 | So there is instances where um come man here we go where it can |
|
| 11:37 | unbound right temporarily. In very rare that's unbound in that situation. But |
|
| 11:43 | those times to get a little bit transcription, this is what allows us |
|
| 11:47 | produce this guy here, which will enable us to see black horses out |
|
| 11:52 | . Okay, we can ramp that greatly in the in the presence of |
|
| 11:58 | . As you see here. Like comes in. Okay. And we're |
|
| 12:03 | break it down right, committed collective is the lack of Z product And |
|
| 12:11 | reform the two sugars like just I cried and then um produce also |
|
| 12:19 | aloe lactose as well. Okay, alot lactose is the actual inducer that |
|
| 12:25 | see there. Okay, so uh that will buy into the repressor and |
|
| 12:32 | falls off. Okay, so and we get lots of expression. |
|
| 12:39 | so again like glucose absent lactose This is what's going on. |
|
| 12:45 | Um and let's see if they show cyclic GMP refreshes the activator complex. |
|
| 12:53 | forms lots of expression. Okay, at the lactose present. Okay, |
|
| 13:00 | induction occurs then. Who goes Okay, now get repression? |
|
| 13:08 | second imperial would drop and don't forget activate a complex. And so we |
|
| 13:14 | get we don't get very good expression occurring glucose is overriding. Okay, |
|
| 13:20 | uh so I also remember that that . Let me go over here. |
|
| 13:26 | will show it. No, they show it in this animation. Remember |
|
| 13:33 | glucose presence of glucose can inhibit lacquer coming into the cell, like interferes |
|
| 13:39 | the lactose permeates. So um so remembering here that um that we need |
|
| 13:50 | have for best expression, high level is lactose is out there, glucose |
|
| 13:57 | not so much lower level of glucose promotes hi second BnP levels which promotes |
|
| 14:05 | activator complex for me. So all together is what brings you highlight expression |
|
| 14:12 | last opera. And so as we to the tryptophan opera now. |
|
| 14:17 | so let's look at a question that to that. Okay, so it's |
|
| 14:23 | about the trip trip to Panama Uh I'll refer to this trip |
|
| 14:29 | Just abbreviate, but it means the thing. Okay, so these four |
|
| 14:35 | then, which is possibly true. trying. Mhm. Yeah, |
|
| 15:20 | Okay. Ship. Okay, here we go. I'm not |
|
| 15:36 | Just give it a shot. the majority is correct. It |
|
| 15:49 | This is correct. Okay. Um metabolic pathway for the what? A |
|
| 15:57 | man metabolism synthesis, synthesis of trip . Okay, um and the answer |
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| 16:10 | a co oppressor. The tryptophan operation he expressed. Okay, as we'll |
|
| 16:19 | the repression of the opposite occurs when is absent. Okay, so remember |
|
| 16:28 | is to block expression. The repression the opposite we allowed expression. |
|
| 16:34 | so we're gonna go through all these right now. Okay, so |
|
| 16:39 | this opera is bio synthetic unlike the opera. Okay um this is a |
|
| 16:46 | the works in a similar fashion to other in the elastic pathways. |
|
| 16:51 | so the products of the pathway um for enzymes that make a trip to |
|
| 16:59 | . Okay. And so should define of basically kind of self regulates the |
|
| 17:06 | process. Okay, as I mentioned , this there is another mechanism that |
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| 17:12 | on top of this is a trip fan. You can actually interfere with |
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| 17:17 | enzyme and that too will stop So that's a post translation in |
|
| 17:24 | Were messing with the protein itself. . And so um the uh regulation |
|
| 17:34 | repressor protein produced by the regulatory green Okay. And so the apolo |
|
| 17:41 | Okay. Is the form that is active, it's inactive. Okay, |
|
| 17:47 | to make it active we need to the co repressor present and the core |
|
| 17:52 | is okay, so when low or to defend president, you get |
|
| 18:00 | Okay. If crypto fan is present such then it becomes active. |
|
| 18:08 | So then the question is when does cell accumulate When to sell Cuban trip |
|
| 18:14 | fans And when this trip to fans not so high levels in the |
|
| 18:17 | Okay. All high the fans. you know, acid middle class issues |
|
| 18:22 | proteins, protein synthesis is greatest during . Okay. So if the cells |
|
| 18:29 | actively growing. Okay, it'll likely to defend and the other amino acids |
|
| 18:34 | fast as it's made. Especially if in log phase. Like crazy. |
|
| 18:41 | uh That's a high, high demand protein synthesis. So you're gonna have |
|
| 18:46 | crank out tryptophan and it's going to used probably as fast as made. |
|
| 18:51 | , So the levels of tryptophan in cell, what we call intracellular levels |
|
| 18:56 | gonna be really loved. Okay. for good reason because needs to meet |
|
| 19:03 | demand. And you're gonna when you making tryptophan right? Which means turn |
|
| 19:07 | opera on. Right. So but soon as gross begins to slow |
|
| 19:14 | Okay, that's when this can Okay, so uh so we will |
|
| 19:23 | up in the cell and then of if it's free like this, it's |
|
| 19:27 | to bind that repressor. And so come together to form the active complex |
|
| 19:33 | that binds to the operator blocks Right? So this is um this |
|
| 19:40 | course is repression down here. And this would be the repression up |
|
| 19:48 | . Okay. Depression. Depression. . And the presidents of tryptophan or |
|
| 19:56 | is what influences what what state you're . Okay. Am I going to |
|
| 19:59 | repressed? Well, there must be of different events. My dear request |
|
| 20:04 | not be there. It's being Okay. Um And that's that's the |
|
| 20:10 | . Right? Remember this is the of lactose opera for the presence of |
|
| 20:16 | uh promoted expression here. The presence tryptophan. An impressive expression. |
|
| 20:25 | Um Now we're gonna look at an method on top of this here in |
|
| 20:31 | second called the attenuation mechanism. but what you're seeing here controls |
|
| 20:43 | of the control occurs through this. . Um but you can still get |
|
| 20:49 | little bit of expression and when you want it. So what the mechanism |
|
| 20:56 | helps you clamp down on that? . To really shut it off is |
|
| 21:01 | attenuation mechanism which we'll talk about in few minutes. Okay. But that |
|
| 21:07 | relies on this here. Okay. sequence this leader sequence called trip |
|
| 21:16 | Okay this is part of the you the turn their attention. Okay so |
|
| 21:23 | little pieces involved in that process. uh So the the. Okay so |
|
| 21:33 | this point any questions about japan We're gonna get a couple of questions |
|
| 21:38 | . Let's look at this. This here. Okay. When we took |
|
| 21:42 | family present growth typically tied to growth all the amino acids and proteins involved |
|
| 21:47 | are gonna be used for protein It's growth that's going to determine for |
|
| 21:51 | most part. Okay. Okay, here is an example here. This |
|
| 21:57 | a clicker question. It's just a I don't answer any questions. So |
|
| 22:03 | e coli which is which is which ferment lactose. You can use lactose |
|
| 22:09 | plus it synthesizes trip to fan. . Is grown in a minimal |
|
| 22:16 | Recall that from Chapter four. Um minimal medium containing both lactose and tripped |
|
| 22:23 | . Okay, no glucose is Okay, sands, glucose. |
|
| 22:30 | So um what can you say about cells with respect to lack and trip |
|
| 22:36 | respectively. So we have two columns and Trip operas. So is the |
|
| 22:41 | peron expressed? Damn it. To pen activated. Okay. Yes it |
|
| 22:50 | . Okay. Um We're growing black present. No glucose. That's that's |
|
| 22:58 | that's your crew. Okay. We're gonna be expressing the what about |
|
| 23:03 | trip to yes or no because because tryptophan is present, is present in |
|
| 23:13 | meeting is present, present in the . The seller will take him. |
|
| 23:18 | . And use it. The cells will definitely take it up because why |
|
| 23:23 | energy making it if I've got Like if I was fooling in |
|
| 23:27 | No need to make it. I've it. Okay so no need no |
|
| 23:30 | to synthesize. Okay. Um So the lac operation side, what is |
|
| 23:37 | state of the repression? Thank Uh correct. It's inactive because we're |
|
| 23:48 | lactose is present because absolute were expressing . It's going to be inactive. |
|
| 23:53 | . If it were active it will stopping trying to stop expression. |
|
| 23:56 | so when the trip operation side it's dr And Yes. Right? Because |
|
| 24:03 | are uh tricked fans out there combined repress her and activating. Right? |
|
| 24:10 | So on the right hand side it's the GMP levels are high or |
|
| 24:16 | Yeah because again it's one of the about the lack opera because absent like |
|
| 24:23 | president um inactive repressor and then cycle levels are rising. That will promote |
|
| 24:30 | activator complex for it. Okay so let's see I think. All |
|
| 24:38 | So you do you know be able compare and contrast these 22 operas. |
|
| 24:46 | . Do look at the animations. think they help. Okay we'll see |
|
| 24:50 | in a second for Trip to fancy as well. Yeah. Right. |
|
| 24:59 | would be a trigger. So uh growth. Whether it's running our nutrients |
|
| 25:04 | or or something is stressing it that have caused it to stop growing. |
|
| 25:08 | those are instances where where the amino not just but all the acids are |
|
| 25:14 | be there's gonna be a demand for so if they're being made then they |
|
| 25:18 | accumulate. So everyone to shut that . Right? So growth the state |
|
| 25:22 | the cell is growing. Is it growing? I did not grow because |
|
| 25:25 | made of food or some other That's gonna be a trick. Any |
|
| 25:30 | questions Jack. So that's part Okay so um So in part two |
|
| 25:40 | kind of all we're gonna do in of part two today is just the |
|
| 25:44 | of the Tryptophan opera. Okay and the second part of how that |
|
| 25:49 | Okay so um there's gonna be a tricky. Okay. I would think |
|
| 25:57 | the mechanism we just looked at, know when the pressure's on or off |
|
| 26:01 | what causes it to be on or that can be easier to grasp. |
|
| 26:06 | this um this can be a little tricky because it's unusual in that the |
|
| 26:12 | don't is actually the mechanism that is you're allowing or not allowing transcription. |
|
| 26:24 | . It's not a it's not a person or introduce or anything doing |
|
| 26:27 | It's a it's the rivals and it's the rivals of position on a transcript |
|
| 26:33 | influences whether we get true opera Sounds kind of weird but that's that's |
|
| 26:40 | it works. Right? And it's based on this trip leader sequence I |
|
| 26:45 | earlier. Okay that comes right before that's that's the key thing to remember |
|
| 26:52 | this sequence and words placed. It's before. So this trip E. |
|
| 26:59 | the start of the structural genes. so if we if we if there |
|
| 27:04 | any problems raise Okay, begins to into that region. Okay. And |
|
| 27:14 | . That's gonna be the start of . It's gonna transcribe those genes. |
|
| 27:18 | ? So that's the do or die is there? Okay well we're gonna |
|
| 27:23 | it we're gonna let this happen or . Okay. It's all based on |
|
| 27:28 | positioning of the tribal zones as it's translating the leader sequence. Okay so |
|
| 27:35 | uh and so that is the leader right there. It doesn't code for |
|
| 27:42 | . Alright. It's only there as regulatory element. Okay so it is |
|
| 27:49 | . Okay. It is transcribed before get to the essential information. Okay |
|
| 27:57 | uh so the bigger sequence um has secondary structures that can form. I |
|
| 28:06 | like already they're single stranded but they form different kinds of loops and structures |
|
| 28:14 | things. Okay so and and all that is just complementary base pairing native |
|
| 28:20 | 18 A. D. U. . To C. Okay. And |
|
| 28:24 | for this uh leader sequence that's there are multiple regions that can do |
|
| 28:31 | . And so you see two of there. Right. The one and |
|
| 28:33 | they call it? One and Right and 23 and four. And |
|
| 28:36 | also a two and 3 regions. . And that one is actually what |
|
| 28:43 | call the anti attenuate. Er Okay all any three of those performances all |
|
| 28:54 | under that. Okay, if you just a plop plop plop that leader |
|
| 29:01 | into a buffer by itself, you assume secondary structure and the most energetically |
|
| 29:08 | one. That forms is actually the . Alright. That would form if |
|
| 29:13 | just like do something but we influence influences which ones form is that this |
|
| 29:22 | ? Tenuously loop Or this one. . Which one forms is all about |
|
| 29:28 | the rivals um is at? so because it covered up, it's |
|
| 29:33 | big it's a big complex, it's little cover up part of that transcript |
|
| 29:39 | then where it stops kind of is which loop forms. That's how it |
|
| 29:46 | as kind of a sensor here. , so, so some of the |
|
| 29:51 | that are involved with this, are the TRS remember? Arriba zones |
|
| 29:57 | course translate and they translate? Um translate by the, you know, |
|
| 30:09 | tr N. S. Right? , right? Charged and uncharged. |
|
| 30:12 | charged ones contain their video action, ones. Do not right. Remember |
|
| 30:19 | each code on here, particularly if have a bigger transfer our name that |
|
| 30:24 | the code on, through the anti on, but then it brings with |
|
| 30:28 | and then we don't ask specific for code. Okay. But you can |
|
| 30:34 | but you only form your form charged by combining and uncharged with together. |
|
| 30:43 | . And so um so for this it's about what's the prevalence of |
|
| 30:51 | Tryptophan trn A's right, these how much of these guys are around |
|
| 30:58 | to these guys uncharged? One strip that, so you combine that with |
|
| 31:09 | These two things. One to stop on. Okay. And two adjacent |
|
| 31:16 | cartoons. Okay. And so you the positioning, one is positioned here |
|
| 31:21 | the other position here, so whether the riding zone is going to stop |
|
| 31:29 | one of those two places. Depending on where it stops, determines |
|
| 31:34 | you form the continuous loop for the attention. Okay, that's what I |
|
| 31:40 | by the positioning of the Robinson, what controls the whole thing. |
|
| 31:45 | and there's factors that determine where where it stalls we call it |
|
| 31:50 | Okay so again the stem loop structures former audience inspiring? Where's the on |
|
| 32:00 | transcript? Right. And that's controlled these two points. Is it the |
|
| 32:07 | or is it gonna stop? Their stop putting and that's going to determine |
|
| 32:12 | luke forms? Okay so let's look here. Alright, so high trip |
|
| 32:19 | fan. Love it. Okay so the attenuation mechanism, The the the |
|
| 32:28 | code pressure, that mechanism we saw , you know that's the majority of |
|
| 32:33 | control 95% of. Okay but this actually stops a little bit, a |
|
| 32:39 | bit that doesn't that that one doesn't . Okay. But um so many |
|
| 32:45 | high triglyceride levels. Okay you're a trip to fan, you likely have |
|
| 32:51 | of, do you have lots of ? Lots of uncharged. There's lots |
|
| 33:00 | trips to find around. You can more or less charged to urinate. |
|
| 33:09 | has to be all right, we more, of course we have more |
|
| 33:14 | to fan around and then that's when this onto the T. R. |
|
| 33:20 | . I have lots of lots of er if you have lots of, |
|
| 33:25 | so what that means is um when environment zone was on the computer sequence |
|
| 33:32 | it's translating. Okay, where is ? Black spot? It's gonna spark |
|
| 33:39 | the usual spot at the stop code . Okay the normal stop coding, |
|
| 33:45 | gonna go past the triple coupons. And so by stopping at that location |
|
| 33:53 | ? That you see here, that up any ability to make it 3-3 |
|
| 34:00 | the anti anywhere. Okay. So what's promoted now is 234. |
|
| 34:09 | And so also notice the the distance . Okay. Between so remember you |
|
| 34:17 | the RNA polymerase running ahead, Transcribing? Right? So this is |
|
| 34:22 | RNA polymerase here, so it's transcribed . What's out in front? |
|
| 34:28 | And now remember this this area here the danger point. Okay. That's |
|
| 34:36 | you want to stop it. If want to stop it, you don't |
|
| 34:38 | it to go into structural genes. so that's and so that's where the |
|
| 34:45 | takes place. Okay so the hairpin that forms the 34. The itinerary |
|
| 34:51 | is in close contact with that memory knocks it off. As you see |
|
| 34:56 | . Just well then being knocked off you don't you don't go any |
|
| 35:02 | Right? Which is what you want you ever sell around, you don't |
|
| 35:06 | to make more tryptophan. So you want that plumbers to go into the |
|
| 35:11 | trip. E. E. C. B. A. |
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| 35:14 | That's because that's gonna make the cell and you don't want to do |
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| 35:17 | You want to talk before then. . It all ties back to lots |
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| 35:25 | charged. Should uh T RNA. ? So you have lots of |
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| 35:36 | you don't stall at the strip club you would stall here. Right? |
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| 35:42 | would stall there if you didn't have had very little or no charged tr |
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| 35:52 | what happens in the next as we'll here? Right low to defend |
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| 35:57 | You have these guys. Right? uncharged ones. Okay. The uncharged |
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| 36:06 | , So they don't have unlike this . Right? These are the charged |
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| 36:10 | here. Okay. So they don't the trip to found. Okay, |
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| 36:15 | when this thing with that T. . N. A. Plopped down |
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| 36:19 | a trip code on there's no trip find any lasted there. Right? |
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| 36:24 | can't Right? That's where you make bonds. Right? So you have |
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| 36:29 | two of these uncharged trip tr sitting and no tryptophan there to link |
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| 36:36 | So it's going to stall? It at that point. Okay. And |
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| 36:41 | those adjacent trip cotton's come before Right? So it's all about |
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| 36:47 | Right? So they're gonna so the person is going to stall here. |
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| 36:52 | . And now that two region isn't up anymore. Right? It was |
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| 36:58 | . Here is number two right Alright, covered in that scenario, |
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| 37:02 | defend, but in low it's And so the anti itinerary. The |
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| 37:07 | , right? That can form. . And so now note the |
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| 37:12 | All right, between that loop and implementation running ahead of it. |
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| 37:18 | Much farther away, so it can't . Right? So it keeps |
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| 37:23 | Okay. And we transcribed structural Right? So it um it promotes |
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| 37:31 | the expression of the genes. And it's all it's kind of all one |
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| 37:36 | leads to another, right? So level of crypto fan, right? |
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| 37:41 | is what's controlling things. So low fan um less charge T. RNA |
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| 37:50 | more of these? Okay. I on going down the transcript gets to |
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| 37:58 | trip to code on and there's two a row. Right? Well there's |
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| 38:03 | a lot of charge T. Trip . R. A. So it's |
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| 38:07 | that guy, right? So it's plug in, right? But there's |
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| 38:11 | real answer to The link together. it's going to stall the whole |
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| 38:16 | right? And that's what enables the loop to form, right? Anti |
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| 38:22 | . So you get expression of those which is what you want because your |
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| 38:26 | trip to things. Okay. Um the opposite is that it's high. |
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| 38:32 | ? You have lots of the They're gonna blow right past these two |
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| 38:37 | codacons because many lessons are there on T. R. D. |
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| 38:40 | So they can be linked to linked and extend the chain. Right? |
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| 38:45 | then it's and then so it will stop at the usual normal spot, |
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| 38:51 | arrival zone would stop that to stop on it. Okay. And that |
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| 38:56 | happens to be Where it covers up two regions. So 3344 um Taylor |
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| 39:04 | and that's what that knocks off diploma . Okay so let's um look |
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| 39:13 | Mhm. Okay. Okay so here's trip to fan opteron there's our shut |
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| 39:27 | . Okay so there's the opera and structural genes you see the leader sequence |
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| 39:35 | . Okay so of course transcript codes the enzymes that make crypto fan as |
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| 39:40 | see. And the let's see how thing. Okay so there's our oppressor |
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| 39:49 | ? The core oppressor if present will and then that will bind. Make |
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| 39:54 | active repressor, binds the operator, what they call a holo repressor. |
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| 40:00 | so it will bind to the There we go. No uh that |
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| 40:06 | this is the this is the majority the control, is this what you're |
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| 40:09 | there? Okay um and then of in the mechanism so here is our |
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| 40:21 | sequence. Okay let's speed this up little bit. Okay so we're going |
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| 40:30 | transcribe the leader sequence you see there a different stem loop structures that can |
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| 40:36 | . Okay. 23. Okay or the 12 and and a 12. |
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| 40:46 | the stem loop continue later. And that's so let's kind of go through |
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| 40:52 | mechanisms kind of give you an overview first let's go through. Okay |
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| 40:58 | Which are okay so now e The code in here. Okay so |
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| 41:13 | code on the trip Cardin's and and levels of tryptophan. Okay we think |
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| 41:23 | kind of there we go. So an expression of leader sequence. |
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| 41:31 | there we go, write his own . Remember, drivers on binding site |
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| 41:37 | there we get the attenuated loop performs it goes through this trip code |
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| 41:44 | it doesn't stop until the stop code . Okay. And that's enough during |
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| 41:49 | loop is in proximity to the primaries knock it off. Okay. And |
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| 41:54 | we go. So in the low scenario, right? There's our leader |
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| 42:03 | , there's a rebel zone. It's stall at those trip codacons, |
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| 42:07 | But the proximity of the loop to preliminaries is far away so it's not |
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| 42:11 | to interfere with it and it can ahead and transcribe. Okay, the |
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| 42:16 | genes. Okay, keeps going. , so again this is just a |
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| 42:24 | an additional safeguard to either really clamp or make sure we get some |
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| 42:30 | Okay um so let's look at. , is there any questions? This |
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| 42:37 | this is one of the mechanisms you have, it really does look at |
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| 42:40 | animation to kind of get in Yeah, so those shapes and forms |
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| 42:45 | things like that. Yeah. So you were to take that um That |
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| 42:53 | trans that leader sequence and just with else around and put it in a |
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| 42:58 | , it would most of the time the 23 actually that's the most energetically |
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| 43:04 | loop that forms but because we have on going on there translated. |
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| 43:11 | That's going to influence whatever conforming because it's just covering up covering up the |
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| 43:17 | regions. For example if it started so that then that enables it physically |
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| 43:22 | that form. But it would have . That's the most favorable. But |
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| 43:26 | that's what arrives in really influencing what's on. Okay. Yeah. |
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| 43:33 | So yeah, this mechanism is wanting kind of have to wrap your head |
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| 43:37 | but if you think about it you know, you begin with high |
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| 43:42 | low tryptophan and kind of work your from there. Okay. Hi tryptophan |
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| 43:46 | what do you have? And you to think of these molecules of the |
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| 43:49 | levels. The trip to fan uh . R. N. A. |
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| 43:55 | . Okay. Because that's linked together the amount of truth defend present. |
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| 44:00 | then that that influences where the riders stopped because they have two choices. |
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| 44:07 | to trip Cardin's side by side. can stall there or you can just |
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| 44:12 | . The stock word stops. All on the level of tryptophan which influences |
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| 44:19 | uncharged Tr N. A. For tryptophan right? Which influences what |
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| 44:24 | it stops, which influences which Right? So it all connects |
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| 44:29 | Okay, that's kind of how to about it. But do look at |
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| 44:33 | the animation. Okay, so let's at the question here. So the |
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| 44:39 | mechanism that helps block expression. Of the tip opera would include all |
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| 44:46 | following. Except which of these? me hoping that. So we're looking |
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| 44:59 | the exception here. Mhm. Okay. Please stop. Mm |
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| 46:02 | Mhm. Okay. Let's see what get here. Okay. Um, |
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| 46:19 | the majority the majority was correct with be Yeah. Mhm. Okay. |
|
| 46:28 | whether you um have attenuation if you , you're going to produce that leader |
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| 46:34 | regardless. Okay. So a is to be a part of it regardless |
|
| 46:38 | if it's blocking or not blocking you're gonna have the leader sequence for |
|
| 46:42 | . Um of course every blank expression all about form in the continuously |
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| 46:47 | Right? So attenuate means to limit to stop. Okay. Um you |
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| 46:52 | , you're gonna have high levels of . If you're blocking expression, then |
|
| 46:56 | doing so because you have enough tryptophan . Okay. So, uh, |
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| 47:01 | the wrappers was gonna stall in this . The rivals was going to stall |
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| 47:06 | the stop code ons not the right you have lots of trip to fans |
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| 47:15 | you have lots of charged trip which means you're going to go through |
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| 47:19 | trip coders and stop at the stop on and that's what promotes the |
|
| 47:24 | Okay. Um Any questions. So the, so this okay, |
|
| 47:33 | one I got about five more So that's um, so this is |
|
| 47:37 | of again, analyzing the different parts the process here. Right? So |
|
| 47:42 | versus high trip level. So synthesize to fan um low. Yeah, |
|
| 47:53 | yes or no. That's what What? Um Hello. All |
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| 48:00 | As soon as I took the fan uh low interest. Yes, I |
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| 48:06 | you did anyway, load interesting trip . Yes. You're gonna send a |
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| 48:10 | trip to family. Okay. Hi levels. No, of course. |
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| 48:14 | . Transcribed the opera. Low intracellular . Let's see. Yes. |
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| 48:24 | Low levels need to make need Might be going to transcribe it. |
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| 48:29 | . Hi adversarial levels. No, strip co repressor repressor complex form under |
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| 48:35 | levels and high levels. Yeah. . Charge trip transfer RNA is |
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| 48:45 | Low. Yeah. Yes. grab some stalls at right assaulted trip |
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| 48:54 | ons stop photons. Okay. Which leader sequence performs anti tenure later. |
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| 49:01 | these kind of things that kind of to each other under these conditions. |
|
| 49:05 | . Just another way of looking at . So um so again, I |
|
| 49:11 | you to look at the animations, black opera. Uh Turn on the |
|
| 49:17 | . Text with both of those animations that can kind of get you through |
|
| 49:21 | . Um Also listen to me Okay um so I mean, how |
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| 49:29 | questions are you going to see on on the exam? A total honesty |
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| 49:34 | maybe like four questions. four or questions times. Okay. Uh 24 |
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| 49:43 | to for lack of a round two the tip off. Some general |
|
| 49:48 | Alright folks. Uh That's it for . We'll see you on |
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