| 00:04 | mhm mm. All right. Alright , let's go ahead and get |
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| 00:32 | So again, um material we've been about this week, uh Tuesday. |
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| 00:39 | is not is not on exam Alright, so we've started unit two |
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| 00:46 | here on Tuesday. Okay, so is the material that's gonna be on |
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| 00:51 | be on exams to. Okay. is a ways away. Okay, |
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| 00:58 | um of course exam ones tomorrow um saturday, depending on when you signed |
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| 01:06 | . Um So um weekly blackboard mastering assignment um will be on schedule |
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| 01:18 | week again, but not due until , so just remember that. So |
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| 01:26 | today um the we're gonna go into this chapter Chapter eight will cover over |
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| 01:37 | couple of days is molecular genetics, we're gonna you're not gonna be expected |
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| 01:42 | know the details of how many replicates details of protein synthesis. Okay, |
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| 01:50 | more an overview type of thing. , overview knowledge of it. |
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| 01:56 | you need to know some of the , but not, I don't expect |
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| 02:00 | to regurgitate here is all the dirty of how you do these processes. |
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| 02:06 | more what's the what's the what's this ? Kind of a thing. |
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| 02:10 | so as we go through this, I don't cover for that reason. |
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| 02:18 | don't cover everything that's in that There's a lot of details in |
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| 02:21 | Okay, so be aware of Which is why I put For the |
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| 02:25 | edition the current edition of the textbook . Okay, so if you don't |
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| 02:30 | that addition, then certainly use your notes as kind of a guide |
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| 02:36 | Um because for that because I don't through all the details minutia of these |
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| 02:42 | . It's more what it represents. isn't why it's important these kind of |
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| 02:47 | . Okay and so kind of to it in because obviously here we're kind |
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| 02:53 | wanted to emphasize as much as we uh from my medical healthcare type |
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| 03:00 | Right So of course microbiology. It's disease. Okay so you know it's |
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| 03:06 | basic processes. Well number one these things that obviously occur in all living |
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| 03:12 | . Right? Um whether you're a or a cockroach or a rat or |
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| 03:16 | human or a bacterium. Okay. obviously replicate D. N. |
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| 03:20 | We all expressed genes. Right. DNA RNA protein flow of information. |
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| 03:28 | regulate genes and so all of that's and mutations occur across you know all |
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| 03:34 | many things of course. And so it's you know one of the one |
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| 03:40 | the or these things or how we're related on on this planet among other |
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| 03:45 | . Okay so naturally you're infectious types organisms, pathogens that cause disease. |
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| 03:53 | they express violence genes. Right. features that allow them to cause |
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| 04:00 | Okay mutations occur. Right. That say a infectious agent that normally resides |
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| 04:10 | a particular animal to make the leap infecting a human. Okay in fact |
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| 04:15 | I. D. S. Right infectious diseases occurred. One of the |
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| 04:20 | of course mutations occur and now they're to recognize selves and humans and infect |
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| 04:26 | . So you know it's these processes certainly do relate to you know the |
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| 04:32 | uh microbes that cause disease. For . Okay so kind of you know |
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| 04:37 | way to look at it as we through this. Okay and so some |
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| 04:40 | this is going to be because everybody is very varied backgrounds in terms of |
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| 04:48 | they've had before. Okay and this gonna be one of those areas. |
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| 04:52 | um so some of the review so would be kind of pressure. So |
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| 04:57 | will be kind of, I'm not sure I may need to may need |
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| 05:01 | go back and look at this So that's why we have some kind |
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| 05:04 | introduce some basic concepts in the So if you've seen this before well |
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| 05:10 | see it again but you know it's won't hurt to see it one more |
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| 05:14 | . So and we start always start section with this question because this will |
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| 05:20 | will absolutely weed out those that really the process and those that don't. |
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| 05:26 | so two part question. So let's at this question. So the process |
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| 05:31 | transcription and translation. So it assumes know what that is okay is carried |
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| 05:36 | in the test tube to a test is added from a hippo hippopotamus. |
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| 05:42 | . R. N. A. . RNA ribosomes from a fish |
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| 05:46 | N. A. From a zebra a plane race other necessary enzymes. |
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| 05:51 | nucleotides and amino acids. Okay, um assume in that test tube some |
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| 06:01 | protein is made. Okay. The of which animal will it represent that |
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| 06:08 | protein that is synthesized? Um Who is it coming from? Okay. |
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| 06:15 | we have few choices here. Is just hippo only the hippo only efficiently |
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| 06:20 | zebra or some combination? Okay. hold that over. So of course |
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| 06:28 | the operative process you were talking Right transcription, translation. So you |
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| 06:35 | to have some remembrance of that and involved in those components because this |
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| 06:42 | sorry? Uh It is open. . So because um this uh this |
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| 06:52 | of course gene expression of what's going here. Okay, expressing the gene |
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| 06:57 | the form of protein. Okay. so we'll go through kind of the |
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| 07:01 | of this, what this means. and if you're not sure here, |
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| 07:07 | fine. So this this part of lecture is about trying to hope to |
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| 07:12 | you understand that. So if you're 100% sure that's no problem. Okay |
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| 07:20 | your best guess. Okay Then we another question coming after this one and |
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| 07:32 | take a break for a bit. . Right. Alright. On the |
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| 07:53 | down from four 321. See okay B. And E. Sensibility |
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| 08:06 | Okay, so as I figured um . N. A. Right so |
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| 08:14 | . N. A. So the of information, right. D. |
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| 08:16 | . A. two r. a. two proteins. That's the |
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| 08:24 | what they call central dogma of How information flows in all living |
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| 08:31 | Uh flow of information is about um these seemingly random letters right? You're |
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| 08:39 | G. C. S. And . S. Right? It seems |
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| 08:42 | be like this random order. But they're not it's not by far |
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| 08:46 | not random. But nonetheless getting that a workable form. Right? Because |
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| 08:51 | what does all the work in cells US right, proteins, two different |
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| 08:55 | , Right, carry out metabolic structural functions, this and that. |
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| 09:00 | . So that getting that it's encoded course, as we as we all |
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| 09:06 | in the D. N. Right? So but D. |
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| 09:09 | A. In itself and those random random letters can't do the work. |
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| 09:15 | ? You have to get it into form that can that's the protein. |
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| 09:18 | ? So it's a route we take do that. Okay. So certainly |
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| 09:23 | protein made in this test tube, definitely gonna be one of your choices |
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| 09:27 | a fish because D. N. . Dead spot. Right here, |
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| 09:31 | D. N. A. Right of course the blueprint, right? |
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| 09:36 | what we're expressing expressing in gene in DNA. Whatever this protein is. |
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| 09:40 | , so fish is definitely gonna be may be the only one but there's |
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| 09:46 | to be in your answer there. is there something else? What's another |
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| 09:51 | if present? Can also yield to of that protein anybody which type of |
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| 10:00 | name. What's The Other 1? . RNA? Messenger RNA. So |
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| 10:11 | you got this all these components and got D. N. A. |
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| 10:15 | there certainly DNA will be expressed because got the components to do that. |
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| 10:20 | if you also have this just hanging , okay because that's because that's in |
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| 10:27 | DNA to RNA to proteins of course fits in these fit in the middle |
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| 10:33 | , right in that part and um make the protein. Okay so you |
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| 10:40 | plop the transcript itself. So M messenger RNA transcript all mean the same |
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| 10:45 | . You can you can plop that and that will be translated. Okay |
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| 10:50 | it's gonna be the hippo and Okay so um let's look at the |
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| 10:58 | question. Right so just again it's kind of testing your knowledge of basically |
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| 11:02 | translation. So let's look at the one. We'll kind of do some |
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| 11:07 | stuff here. Alright, so this is about genotype. So there's lots |
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| 11:12 | terms of course when you start talking this subject and genotype is one of |
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| 11:17 | . So which is among these faults a genotype. Okay. It is |
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| 11:25 | . It is usually represented as N. A. It's not always |
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| 11:32 | it can change it only represents the characteristics of an organism. Um Not |
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| 11:42 | faults. They're all true. Okay count down 10. 54. |
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| 12:38 | 21. Alright. Okay. Um is false. Let's see. Um |
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| 12:51 | he is the false statement. Okay of course it's heritable. Right? |
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| 12:58 | are. We all know genotype genotype the D. N. A. |
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| 13:02 | course. Okay jeans making up the of jeans and well basically the |
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| 13:12 | N. A. And orgasm. . Obviously it's heritable. Right. |
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| 13:17 | it was expressed representative D. A. Okay that's true for |
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| 13:23 | But when is it not representative in ? Who would do that? It's |
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| 13:29 | microbe that can do is uh we've seen a lot of cases of one |
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| 13:36 | type of this in the past two viruses. RNA or RNA viruses like |
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| 13:44 | . So the genome for it is . Okay and that's true for many |
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| 13:49 | of viruses. Measles mumps, um mumps, rabies, uh Ebola West |
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| 13:58 | virus. Lots of viruses that cause disease are actually RNA viruses so that |
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| 14:02 | have an RNA genome but it is true that it's usually represented D. |
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| 14:07 | . A. Okay. Um it's always expressed. So Point C. |
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| 14:12 | very important because um as important as as it is to express jeans when |
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| 14:20 | need them. It's equally important to . Control is a huge part of |
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| 14:25 | process. Um It can be quite in humans and other you carry |
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| 14:31 | Um But for any organism you want be able to turn on genes that |
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| 14:37 | need and only those that you need a certain point and then be able |
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| 14:40 | turn them off just as quickly. . Because again you have to always |
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| 14:45 | , right? Because out in nature is competing with each other. |
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| 14:49 | Any kind of edge you can get edge. Can be being efficient, |
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| 14:55 | ? Makes you a better competitor able survive better. So, certainly controlling |
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| 15:00 | genes are turning off and on going play a big part in that. |
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| 15:03 | , so that's that's a huge Um the it can change certainly mutation |
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| 15:10 | can create changes in those bases and a different type of genotype and consequently |
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| 15:20 | change the protein that's made. Um now the the verbal characteristics. |
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| 15:26 | genotype is the um I'll call it . Right for for specifying the various |
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| 15:36 | in the cell. Okay. we can take that blueprint and work |
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| 15:41 | it and make copies and convert that a protein. Okay. Um, |
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| 15:48 | because of the fact we have control jeans, right, No one organism |
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| 15:53 | this planet is expressing every single one its genes. Okay, There are |
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| 15:58 | you haven't expressed since zygote plus 10 , Right? Because you needed those |
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| 16:06 | to kind of get you from the to 10 days worth of development. |
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| 16:11 | . And then as you're going to stage, um you know, once |
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| 16:15 | get out of the womb. Right there's a bunch of genes that you |
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| 16:19 | need anymore because you're fully developed. ? So but there are lots of |
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| 16:27 | um Not everything you have in your you necessarily see. Right? Um |
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| 16:34 | have lots of metabolic reactions going on you. You don't you don't see |
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| 16:37 | going on. But there's nonetheless there there are traits. So and so |
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| 16:43 | why the term phenotype. Right? heard of that. I'm sure Sophina |
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| 16:50 | represents those that part of the genome being expressed right to produce a particular |
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| 17:00 | , right? Which may not always observable. Okay, certainly we can |
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| 17:04 | blue eyes. Right? But you not see certain types of metabolic reactions |
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| 17:09 | on and what they do. so but anyway, so it's it's |
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| 17:14 | uh so that phenotype genotype connection Okay, so we'll talk we'll start |
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| 17:19 | that. Okay, so here are of you in lab. So this |
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| 17:24 | look familiar. Um The until next we'll start doing this one lab. |
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| 17:30 | lactose bras. But regardless the point is um different viewpoints genotype phenotype. |
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| 17:38 | , so what we can see this an example of what we can see |
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| 17:42 | terms of features of a microbe. , so ability to use this sugar |
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| 17:48 | of sugar. If you can ferment change the ph and acidified. And |
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| 17:53 | that's why it looks yellow, there's ph indicator. Changing yellow when acid |
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| 17:58 | one is not So indicates it can can't use lactose sugar easily observable |
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| 18:04 | right? We can do the same by growing it on the plate. |
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| 18:08 | know, producing colonies. And with the same kind of ph |
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| 18:12 | We produce different colored colonies depending on they can ferment or not ferment |
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| 18:17 | Very basic kind of thing appear. blood auger. Right? If the |
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| 18:23 | capable of releasing this enzyme that can blood cells and you'll see a clearing |
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| 18:28 | . Okay, So all different types phenotype. Okay. And so of |
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| 18:34 | , uh expressing different genes right to these different types. All right. |
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| 18:41 | , here's another way to look at . Okay, So this is um |
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| 18:45 | you're in the lab, I think week you talked about the unknown |
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| 18:49 | Right? You're gonna be doing starting next week. So, um If |
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| 18:55 | you have the capability, okay, could send out for one of these |
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| 19:01 | from one of your local uh scientific company. Okay. And this will |
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| 19:06 | you to do all the tests at time and get your answer in 24 |
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| 19:11 | and be done with the unknown project you just kick your feet back. |
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| 19:14 | ? Unfortunately, we're gonna make a it out a little longer than |
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| 19:17 | Okay, This is what we call is one of these rapid I detest |
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| 19:23 | test kits. And so basically it multiple chambers, right? They're all |
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| 19:28 | , This is different. These tests different types of fermented sugar that sugar |
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| 19:33 | react with this chemical and produce this product these kind of things. Different |
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| 19:38 | tests. And so there's actually a loop. So imagine this is a |
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| 19:43 | loop and this is the the Right? And you take the cap |
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| 19:49 | and exposes a sterile needle. You a colony on a plate and then |
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| 19:54 | go and it pulls out. And you basically as as a little needle |
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| 20:00 | goes along each compartment it's inoculating each compartment itself. So that way you |
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| 20:05 | play everything at one time. And then you incubate and then you'll see |
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| 20:11 | of these chambers will will show up different colors. This one's already been |
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| 20:17 | . So you see different colors relating different results. Some are negative or |
|
| 20:21 | and kind of total it up. get this number code and you look |
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| 20:24 | in a little booklet and it tells it's most likely this. Okay. |
|
| 20:29 | simple. And so um we're just focus on one box. This is |
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| 20:34 | area. This you re a Okay so ability to you to hide |
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| 20:39 | your area is a future that's commonly . Especially among these we're looking here |
|
| 20:46 | enteric bacteria or e coli just sam etcetera. Right? And so um |
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| 20:53 | positive it shows up as a this of fuchsia pinkish color. Okay and |
|
| 20:59 | okay what does that mean? That's an observable peanut type. Right Yuria |
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| 21:06 | the enzyme yuri is positive. this is what they're actually going on |
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| 21:10 | the boxes in that compartment. so we have this in the in |
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| 21:14 | medium, in that in that If the orgasm has the enzyme it'll |
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| 21:18 | that down. Right. This creates ph change. Okay, So the |
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| 21:23 | gene is responsible for this. So genotype, the phenotype says it's |
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| 21:30 | for that. Well then obviously it have genotype possessing a gene. |
|
| 21:34 | so how is it able to um convert that product? Right. It |
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| 21:40 | to make the protein to do Right? You have to do transcription |
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| 21:45 | right? To generate that yuri is . Right? And this is the |
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| 21:52 | every jean must go whether you're whatever form type you are. Okay. |
|
| 22:00 | everything basically uses the same basic There are gonna be some some you |
|
| 22:06 | , slight differences but the way they and and work basically the same. |
|
| 22:13 | so um ultimately we get the So, so we talked about the |
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| 22:19 | central dogma. Right, So D A R N. A. And |
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| 22:25 | of protein up here. Okay, here, right there. The area's |
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| 22:30 | . So, following that pathway. , survivors. OEMs uh tr NH |
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| 22:36 | talk about those in a second. And then performing the protein. There's |
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| 22:41 | protein here and now we have our . Right, so again, this |
|
| 22:47 | one example bacteria on average have 3000 so genes. So when they turn |
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| 22:54 | things on this is basically what's gonna every time. Okay so but we're |
|
| 23:00 | focusing here on here is control. also gonna be controlled. Right? |
|
| 23:05 | Maria unless it's in nature. And your area were not present around |
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| 23:11 | anywhere. This wouldn't be occurring Right. That's the control mechanism. |
|
| 23:16 | do that if it's not needed? one thing you can never see in |
|
| 23:22 | of these illustrations is the amount of it takes to do this. |
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| 23:28 | It takes a lot of energy to the synthesis to make an M. |
|
| 23:32 | . A. To translate into protein put together the OS. Is to |
|
| 23:37 | all this stuff takes energy because we're building stuff right? And Embolism. |
|
| 23:43 | ? That's gonna take a lot of . And so one of the primary |
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| 23:47 | why don't do this. We don't to because you'd be wasting energy. |
|
| 23:52 | so um so uh so we go genotype to phenotype. Right? So |
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| 23:59 | that's how they're linked to the genotype a a observable phenotype. When we |
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| 24:07 | through this expression process, right? to the R. N. |
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| 24:10 | Steps to get to that protein. so um so again phenotype obviously represents |
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| 24:20 | function of proteins. Right? The of proteins going on that are present |
|
| 24:25 | any given time and that can change what's there's a term you need to |
|
| 24:31 | this but there's a term called Okay genome and then there's proteome and |
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| 24:45 | represents the totality of D. A. In a an organism. |
|
| 24:50 | . For a bacterium that can mean chromosome. Plus if the hands associated |
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| 24:56 | right. All that be the The proteome is basically one of the |
|
| 25:02 | being expressed at that given tie. . And where is the genome is |
|
| 25:08 | constant? Right? Because it's always . Right. The chromosome is always |
|
| 25:13 | . Plasmids are usually always there. And so that stays the same. |
|
| 25:19 | ? What changes can be what's being ? Right. X. And Y |
|
| 25:24 | in A. And B. Is . Well then does it switch |
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| 25:28 | Does it change over time? That's the proteome can change. What are |
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| 25:32 | actual proteins present at any given Okay. Um Now the how are |
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| 25:42 | genotype connected? They're connected through um the RNA. Right. It's different |
|
| 25:49 | making up this part of the Okay so um and that involves different |
|
| 25:57 | . As we saw a plane raise R. N. A. Messenger |
|
| 26:01 | . Are part of that process. ribosomes of course. So um changes |
|
| 26:07 | genotype. Right? You have a , right mutation in the genotype which |
|
| 26:13 | talk a little bit about at the how these how these occur um A |
|
| 26:20 | in the A. G. T. And putting those together. |
|
| 26:25 | change A. To something else. . G. That can have a |
|
| 26:29 | effect. Maybe. Maybe not. but that's how you can see a |
|
| 26:33 | in the genotype. Okay. The is preserved through um replication. Okay |
|
| 26:43 | when the cell divides all right So it still gets a copy of |
|
| 26:49 | genome. Right? So you preserve through generations. Right inheritance of copying |
|
| 26:55 | genome in inheritance. So um and think of a way to think of |
|
| 27:00 | is D. N. A. the the book on reserve in the |
|
| 27:05 | . Okay. Can take it home you. It's always there. Okay |
|
| 27:10 | you want information from it generally you copy the whole book. You maybe |
|
| 27:15 | chapter here chapter there. So you chapter. Right? That's now you're |
|
| 27:21 | that's your R. N. Okay that's your RNA and ribosomes and |
|
| 27:25 | . And so the the um the you get at the end it could |
|
| 27:30 | the protein, right? Xerox machine copies and then you have the working |
|
| 27:35 | is your paper. That's the That may be one way to think |
|
| 27:39 | it. Okay so Uh so again here at genome as you just |
|
| 27:48 | Right. So for a for us genome basically are 46 chromosomes right there |
|
| 27:55 | our in ourselves. Um for for creates it can be beyond that. |
|
| 28:02 | . And so um so of course like us we we um pass things |
|
| 28:11 | vertically. So vertical means basically think parent a child. Right. But |
|
| 28:16 | also have the capability as do archaea what we call horizontal transmission. Okay |
|
| 28:22 | um so these are cells existing in population. Okay, neighboring cells. |
|
| 28:30 | . That it can exchange genetic information . Okay and there's different mechanisms of |
|
| 28:37 | . We'll look at that next time like five different mechanisms or four different |
|
| 28:42 | that enable this. Okay. Uh as mentioned before I think you know |
|
| 28:48 | vertical transmission occurs through binary fission and . Right? So zero making identical |
|
| 28:55 | . Right? As we all know A new coli um There's thousands of |
|
| 29:02 | of e. Coli and N. . Coli in your gut. They're |
|
| 29:07 | all going to be identical. There's be slight variations. Okay um and |
|
| 29:14 | variation is the key, right? in any living thing population variation is |
|
| 29:20 | key to survival having more variants in population means um there are options for |
|
| 29:28 | . Population conditions change. Well then there's a particular subset in that group |
|
| 29:34 | has the most favorable combination of genes they survived. Okay so the more |
|
| 29:39 | you have the better. Okay. humans vary between each other by about |
|
| 29:49 | .15%. Somewhere in there is a between unless your identical twin but that |
|
| 29:56 | exists between us. So that's that . So so for something that seemingly |
|
| 30:02 | through a kind of xerox mode of identical through vertical transmission, binary |
|
| 30:10 | No because a they can do horizontal and gain new genes that way of |
|
| 30:17 | mutation. They mutate a little bit rate than we do. So that |
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| 30:22 | variation. So even though they can't sexually which is a big positive mechanism |
|
| 30:29 | us because sexual reproduction leads to the . Right? They don't do that |
|
| 30:33 | they still can of course gain genetic . Okay. Very important. And |
|
| 30:39 | you know if these horizontal mechanisms of how antibiotic resistance often gets transferred from |
|
| 30:45 | to cell. Okay. Um and the replication. So you may again |
|
| 30:52 | not going into the process of replication there's a term you should know this |
|
| 30:57 | conservative. Right? That's how that's life replicates its D. N. |
|
| 31:03 | . Okay and so basically what it is each strand. So here's a |
|
| 31:09 | stranded DNA. Okay so each strand putting them apart. Okay. Is |
|
| 31:15 | template for synthesis. Okay. And kind of the language, the how |
|
| 31:24 | work with the clinic acids and due their structure is that you have these |
|
| 31:31 | labeled five and three relates to don't about it. But it relates to |
|
| 31:36 | nuclear types. And the number of run nuclear types. But anyway so |
|
| 31:41 | nucleic acids uh have these two different of five and three what they call |
|
| 31:47 | five prime and three prime. It doesn't matter if your D. |
|
| 31:50 | . A. Or RNA. The same thing applies. Okay so |
|
| 31:55 | any case each one is a template gonna be able to make a copy |
|
| 31:59 | these two templates. Okay these are two copies. Right? So remember |
|
| 32:03 | complementary base pairing. Right. We're making identical copies. So for example |
|
| 32:09 | sequence is a T. G. . three prime. Sometimes just looking |
|
| 32:17 | that part. Um We're not making T. G. Okay. So |
|
| 32:25 | other thing to remember is this I'm this now because when we get the |
|
| 32:30 | there's a designation for viral types. call them. Especially with RNA |
|
| 32:38 | Right? They can be plus or . Okay. And so you actually |
|
| 32:45 | plus and minus designations on nucleic acid ? Right so one of these is |
|
| 32:52 | plus. Okay and so over here may be the plus the minus |
|
| 33:00 | Right? So similarly then the complementary will be relative looking up top |
|
| 33:08 | B minus now. We plus. . So what we call um since |
|
| 33:18 | that's a plus trend and anti So it basically means is since strand |
|
| 33:28 | strand is the is the strand and the coding information between the essential |
|
| 33:33 | Okay. The antisense strand is the of that? Okay, we can |
|
| 33:40 | the antisense strand. Okay, copy and make a plus trained. Okay |
|
| 33:54 | this is when you get the virus is an RNA virus is this will |
|
| 33:58 | a great daily remember this. Okay this is just this is just how |
|
| 34:03 | work with nucleic acids. That's all is. Okay. It's it's this |
|
| 34:07 | the five and three. It's why have this and this on nucleic acid |
|
| 34:12 | . It's just how they work. . And it's why you don't |
|
| 34:16 | when you copy a template, you make the identical copy like this. |
|
| 34:21 | make the complementary copy. Just the that that's the rules of working with |
|
| 34:28 | acids. So it's gonna be um . T. A. C. |
|
| 34:34 | then the orientation this and this. , just didn't make this up. |
|
| 34:40 | ? This is how it's been for . Okay. Um And so just |
|
| 34:46 | couple of things remember. It may helpful. Okay. But the but |
|
| 34:51 | always and again it doesn't matter if if it's this D. N. |
|
| 34:57 | . D. N. A. . I'm gonna be RNA RNA. |
|
| 35:02 | it could be DNA RNA all R. N. A. |
|
| 35:09 | Possible. All right. 123. all those combinations are possible. And |
|
| 35:18 | same rules apply. One's gonna be and 55 and three. You copy |
|
| 35:23 | ones. The ones gonna be plus minus all that applies. It doesn't |
|
| 35:29 | whether it's just because your familiarity. sure it's mostly with the only DNA |
|
| 35:34 | . Right? But you can have other combinations. Okay. But the |
|
| 35:39 | rules apply. Okay, complementary base prime uh plus minus all that. |
|
| 35:49 | so um the uh okay so when say sense strand. So for example |
|
| 35:57 | D. N. A. Strand contains the actual code. Alright that |
|
| 36:04 | make the protein. That's the plus . Okay the R. N. |
|
| 36:09 | . That's a plus strand. Okay let me just throw this out at |
|
| 36:15 | . Okay if I say there's a RNA strand and the minus RNA strand |
|
| 36:27 | of those RNA. S. Will directly translatable into a protein. |
|
| 36:33 | Plus. Okay how do you? um yes plus trade plus train is |
|
| 36:40 | one containing the relevant information. Okay um so the plus RNA strand would |
|
| 36:47 | been copied from a white type of . A. Plus or minus? |
|
| 36:56 | one? Yes thank you copy from strand. So that plus R. |
|
| 37:03 | . A. Would have been copied a minus strand. Um So remember |
|
| 37:11 | right because when we get the RNA right because in my other class the |
|
| 37:16 | of course we just went through the viruses and I could see eyes going |
|
| 37:23 | when you go through RNA virus life really always dependent on this remembering the |
|
| 37:28 | minus relationship. And when you copy plus you make a minus and again |
|
| 37:33 | just it's just the rules of nucleic . Okay that's that's what we're following |
|
| 37:37 | . Okay um Alright so let's any we'll keep hammering on this a little |
|
| 37:45 | more here but let's look at this . Ok so here's a question this |
|
| 37:51 | going to get us into as you're this um uh the so we talked |
|
| 38:00 | um expression how just from the overview D. N. A. To |
|
| 38:09 | native protein expressing the gene. Um it's okay. Getting a little bit |
|
| 38:16 | the nuts and bolts of that. , it's kind of what this is |
|
| 38:20 | . Okay, so the genetic code the sequence deputizing the gene turned by |
|
| 38:28 | river zone is based on the Messenger sequence determines how many chromosomes are present |
|
| 38:38 | none of the above. Okay, can't down from 10. Okay. |
|
| 39:53 | it does not really determine the sequence nucleotides in the gene. Okay. |
|
| 39:58 | genetic code is what's used to convert genotype into a protein. Okay, |
|
| 40:05 | there's like a code book for it the genetic code is that what determines |
|
| 40:09 | sequence of nucleotides in a gene is uh that's what you inherit. |
|
| 40:15 | And so it's the particular, that sequence determines what the protein will |
|
| 40:20 | Okay, but the rivals um it's the messenger RNA A. Okay, |
|
| 40:29 | is how you decipher the language. , so you're gonna take that transcript |
|
| 40:36 | then. Use the code book right tell you. Okay, this is |
|
| 40:41 | um this is going to turn out be this is the kind of |
|
| 40:44 | It will be because the code specifies the particular Emiel assets. Remember that |
|
| 40:55 | real assets make up a protein. . And so the code specifies what |
|
| 41:04 | would be because it corresponds to a set of nucleotides. Okay. And |
|
| 41:10 | that code is going to help us this out. So here we're looking |
|
| 41:14 | um kind of the overall process. we see A D. N. |
|
| 41:18 | genome, right? DNA template And um and then we see right |
|
| 41:26 | plus And so we kind of have the pickup sequence right here. |
|
| 41:34 | And so you see the designations plus minus strand. Right? And so |
|
| 41:42 | plus strand is the sense strand? coding strand? Anti sense the minus |
|
| 41:47 | . Okay, so we have our types sense antisense. Okay. And |
|
| 41:54 | we're gonna go transcription, translation transcription basically going to make a copy of |
|
| 42:01 | D. N. A. So . N. A. As you |
|
| 42:07 | , there's of course the precious right? You want to we want |
|
| 42:10 | protect it, We want to preserve . And so if we want to |
|
| 42:16 | with it, let's make a And a copy of it. And |
|
| 42:20 | mess with it there. But leave alone. Okay. And so that's |
|
| 42:27 | first process this transcription. Okay, fine because we can always make tons |
|
| 42:34 | transcript if we need to. because DNA is always gonna be |
|
| 42:41 | We always go back and copy more a gene if we need to |
|
| 42:44 | that's what the control is kind of . But if we need to we |
|
| 42:47 | make more, right? It's like xerox machine. It's like the chromosomes |
|
| 42:52 | book on reserve. If you want of the pages we take the xerox |
|
| 42:55 | to make as many as we want go back and make more. |
|
| 42:59 | The same thing. So so to the transcript you need to proliferate, |
|
| 43:04 | the copying enzyme for that. And a transcript. Okay and so the |
|
| 43:10 | is the M. RNA. The RNA. All that's synonymous with each |
|
| 43:15 | . Okay um then I'll just throw in um that this kind of is |
|
| 43:24 | we call A. D. A dependent. The only reason I |
|
| 43:31 | that up that's what we we've That's what almost everything has because the |
|
| 43:39 | polymerase is copying copying this right, that to make that transcript. |
|
| 43:49 | And so the uh other types. we're gonna look at RNA viruses in |
|
| 43:57 | next chapter. Um They have some those have what's called an RNA dependent |
|
| 44:04 | they copied the RNA is into other is right. We don't do |
|
| 44:08 | Okay. And so I just mentioned just just for that reason. Okay |
|
| 44:16 | And so with the transcript then and this is showing a very basic |
|
| 44:22 | You see 1 1 copy here. ? Um the uh in reality hundreds |
|
| 44:33 | not thousands of copies can be made inactivity expressed gene you'll make hundreds if |
|
| 44:40 | thousands of transcripts from that same Okay um Then also remember the the |
|
| 44:48 | poly ribose um or polly's own thing talked about before. Okay, as |
|
| 44:56 | as the transcript is visible. And this ribosome binding site is |
|
| 45:04 | Okay, at the very beginning of transcript then arrives home sees it and |
|
| 45:11 | down right and begins to translate. ? So remember this will be coded |
|
| 45:17 | ribosomes, Right? That's that polly function. So in bacteria and |
|
| 45:21 | So it happens. Lots of protein very quickly. Okay, party zone |
|
| 45:26 | . So um so the translation process what involves kind of that code book |
|
| 45:34 | genetic code, the transcript is gonna those elements and then it's up to |
|
| 45:42 | . R. N. A. of act as the mechanism to recognize |
|
| 45:49 | RNA bases these things. Okay, and so on. And to match |
|
| 45:58 | up with the right amino acid. . And so the ribbons um is |
|
| 46:02 | of that platform where everything comes it holds onto the transcript. It |
|
| 46:11 | a space spots for the trn to in and out. Okay, so |
|
| 46:15 | kind of is the platform where everything happening in terms of protein synthesis. |
|
| 46:21 | . And in fact the the rival themselves also carry out the connecting of |
|
| 46:29 | amino acids, right? They actually catalyze that part of the process. |
|
| 46:35 | , so a lot of stuff happening where the ribosomes are at all this |
|
| 46:40 | occurring and the end result is the of poly peptide. Okay, so |
|
| 46:47 | again this is happening, you can you know lots of transcripts coming out |
|
| 46:52 | here. Lots of riders was bound the transcript and lots of protein being |
|
| 46:56 | . Okay? So um now I that's that's as much in detail as |
|
| 47:04 | need to know about this. Um let's look at this. |
|
| 47:11 | Just a kind of um really? we can understand the sense and antisense |
|
| 47:17 | thing. Okay so uh this is same DNA sequence from the previous |
|
| 47:24 | Okay. And just indicating the plus minus strands here. Okay so the |
|
| 47:32 | going to copy making a copy of sense strand. Okay, so and |
|
| 47:40 | gonna do that right by we're gonna this right here by copying the antisense |
|
| 47:51 | . Right? So if you look the sense M. R. |
|
| 47:53 | A. And the sense D. . A. Right? You can |
|
| 47:56 | how they're identical. Alright. G G G. G. G. |
|
| 48:03 | . Uh except where there's a year so. Right, so in |
|
| 48:08 | N. A. Right? RNA have you instead of tea by |
|
| 48:18 | Okay. So but they match up those spots. So 80 G. |
|
| 48:25 | A U. G. G. . A. Same G. |
|
| 48:28 | A. G. G. G. G. G. So |
|
| 48:30 | all the plus M. R. . And the coding DNA strand |
|
| 48:36 | Okay. And they're identical because the . R. N. A. |
|
| 48:41 | made by copying the minus strand. ? So actually copying that. So |
|
| 48:49 | the army plain rice is copying the strand? Right? That's the |
|
| 48:54 | right? Because in doing so we basically an identical copy of the |
|
| 49:01 | N. A. In an RNA . Okay so that's why we call |
|
| 49:06 | antisense strand the template because when we it in transcription or making an identical |
|
| 49:13 | of the DNA now and because of coding strand, an identical copy of |
|
| 49:18 | coding strand because that's what contains the information right? To make the |
|
| 49:23 | Okay so that's the nature of this anti sentence. And when you copy |
|
| 49:30 | . Okay um any question about Does that make sense? I |
|
| 49:37 | Yeah. Um no pun intended. sense. Okay. Make anti |
|
| 49:43 | Right. Alright. Never mind. Okay so here is uh looking at |
|
| 49:50 | genetic code. Okay so a couple things. So again this is kind |
|
| 49:55 | the playbook if you will code book decipher in M. RNA. So |
|
| 50:00 | that we're looking at the transcript Okay. And you can tell that |
|
| 50:06 | ? You know that because we have a citizen here right? We don't |
|
| 50:11 | any timing showing up. Right? um so it represents R. |
|
| 50:17 | A. Okay uh specifically messenger And so um it's redundant because there's |
|
| 50:25 | . There's only 20 amino acids. . But these um there's more there's |
|
| 50:32 | more than 20 code. So the on. Right is a three base |
|
| 50:37 | base set. Okay. And each base set Groups of them code for |
|
| 50:45 | 20 amino acids. Okay, so have 64 three base code on |
|
| 50:51 | Okay, coding for 20 amino Hence the term it's redundant. |
|
| 50:57 | repeats itself. Right? And you see that, right? Here's scr |
|
| 51:02 | Syrian and there's 44 code ons for . Right? And so on. |
|
| 51:06 | can see this in the various groups . So multiple code owns for |
|
| 51:10 | I mean. Okay, so um here's our D. N. A |
|
| 51:19 | . We copy and make our RNA. And now, so we |
|
| 51:22 | our coding information. Now, we to kind of decipher what's going on |
|
| 51:26 | . Right? We still haven't gotten protein yet. This is where the |
|
| 51:29 | is coming. Right, So you like a sentence, right? If |
|
| 51:33 | were to look at a sentence and sentence, we had all the words |
|
| 51:37 | all continuously put together and no space between. But you need to have |
|
| 51:43 | elements of grammar punctuation, right? figure out what the sentence is. |
|
| 51:46 | same here. Okay? So that in the form of the coordinates. |
|
| 51:50 | ? So you look for a start . Right? So we know the |
|
| 51:54 | of a sentence is the first letter in the first world. Right? |
|
| 51:59 | what directs us to the start of sentence here. It's where's the start |
|
| 52:03 | in. Alright. And so we certain punctuation marks. If you will |
|
| 52:10 | and then stop. Right? So period at the end of the |
|
| 52:16 | Right? This tells us where the is. So for this the stop |
|
| 52:19 | on. Right? So once we the starting point, okay then it's |
|
| 52:25 | 3123123123. And those are your code . So au Jesus start at some |
|
| 52:31 | there'll be a stop one of these stop code ons U A A U |
|
| 52:36 | G U G A. Okay, you get there, that's the |
|
| 52:41 | Okay. And then you've got your peptide which will be uh in this |
|
| 52:49 | A G. Is machining and protein you do not need to memorize these |
|
| 52:55 | obviously. So but just kind of the process. Okay, so this |
|
| 53:02 | all this here is translation of What's going on that you're not seeing |
|
| 53:09 | the nitty gritty details of. Is um this there's gonna be a ribosomes |
|
| 53:22 | here basically occupying two of those slots it's kind of a big molecule. |
|
| 53:30 | , So it looks something like Okay, and this is where you |
|
| 53:36 | T RNA is coming in. Let just do it this way. |
|
| 53:40 | so again, I'm just showing this for completeness of anything else. |
|
| 53:46 | what is this? A U. C C. A. Okay, |
|
| 53:50 | we have the rest of the transcript so we have um rivals. So |
|
| 53:58 | comes in two parts as a small and the big unit, right? |
|
| 54:03 | our rivals. Um And then we'd T RNA molecules coming in, |
|
| 54:10 | That recognize that code on and bring amino acid. That's M. |
|
| 54:15 | T. Short from a tiny And so I always draw my Tr |
|
| 54:20 | . A. S. Like So if it recognizes a U. |
|
| 54:27 | . Then it must have a complimentary A C sequence. Alright, that's |
|
| 54:34 | it links up with a code Right? So this is code on |
|
| 54:42 | . Antico to. Right? So is specific for T. All |
|
| 54:49 | And so you have the amino acid there. Right? So that's how |
|
| 54:52 | work. Right? So that's kind the the kind of really the adapter |
|
| 54:57 | . If you will like a putting three pronged, you have a two |
|
| 55:00 | outlet. You need a three You put that little adapter thing in |
|
| 55:02 | middle. Right? So this thing can recognize the code on at the |
|
| 55:10 | time. Bring the correct amino Right? So then this one will |
|
| 55:14 | in here, right? And I that was pro lean. So |
|
| 55:19 | R. O. And then the own helps to make the link between |
|
| 55:22 | two. And so then the next comes in, right goes this way |
|
| 55:26 | then here comes the next one, next amino acid, a short amino |
|
| 55:32 | and then just keep making a peptide . The zone moves along. |
|
| 55:37 | So again um I expect you to that level of detail. Just kind |
|
| 55:42 | know the overall process going on. . Um the uh any questions about |
|
| 55:51 | part? Okay. All right so look at mutations. So what happens |
|
| 55:57 | in mutations is we're making change to genotype? Okay. Make a change |
|
| 56:05 | the genotype and of course are going make a change in the um protein |
|
| 56:15 | you have a change in the genotype you copy that into a transcript. |
|
| 56:18 | course it's reflected in the transcript as . Okay. And then ultimately when |
|
| 56:24 | the protein when you translate that Okay so um now mutations themselves or |
|
| 56:34 | in genetic sequence um various things cause as I'm sure you're aware UV light |
|
| 56:41 | cause it radiation different types of chemicals what we call collectively called mutations that |
|
| 56:48 | mutations um The ones that are most of course are those that occur in |
|
| 56:58 | gametes. Okay. Um talking about in humans. So in the Gambia |
|
| 57:05 | because you can pass those on to Children of course. Okay. Um |
|
| 57:10 | we call germline mutations. Okay. you know you got you got you |
|
| 57:17 | get sunburned. Right, you're definitely mutations all the years. You have |
|
| 57:22 | system to kind of get rid of bad cells that have been mutated but |
|
| 57:26 | know if it does turn into something I eat skin cancer or something. |
|
| 57:32 | really the only one affected you're not to pass that on to your |
|
| 57:35 | Okay. But if you have a that occurs as a result of this |
|
| 57:39 | in your, you know, eggs sperm, then that could have implications |
|
| 57:45 | on. Okay. Um now the of the mutation. Okay. You |
|
| 57:51 | a change in the base. What's outcome? Is it going to be |
|
| 57:57 | ? 100% of the time? Okay. Um In fact most mutations |
|
| 58:05 | not bad. Okay. They're either . There's no no no difference. |
|
| 58:12 | . And it's no effect. Right all. Um They can be in |
|
| 58:21 | cases lethal. And generally they either there either is no effect or to |
|
| 58:26 | . It's really most of the That's the outcome. Okay. Um |
|
| 58:32 | it can be certainly be beneficial. . And whether it's any of |
|
| 58:39 | you have to look at successive Look at production of offspring. |
|
| 58:47 | Especially if you're trying to assess if beneficial, right? Benefiting the |
|
| 58:52 | Well, if it is then that change is occurring and more and more |
|
| 58:57 | of the population as it grows, it's hanging around because it's something |
|
| 59:02 | Okay. Um and so you can really assess benefit in that way. |
|
| 59:09 | . Is it helping it survive and ? Okay. Um so we use |
|
| 59:17 | term so we're looking at microbes, in particular. Uh we often use |
|
| 59:21 | use this term oxygen. Okay. think we introduced that during growth, |
|
| 59:28 | can't remember. But uh I remember oxide trophy is one that's deficient in |
|
| 59:33 | pathway. And so very often in production of making amino acid. So |
|
| 59:40 | have to have you have to give for example the history aka trove. |
|
| 59:46 | you'll have to give it this amino if you wanted to grow. |
|
| 59:50 | Because it's it's mutated in that particular . Um spontaneous mutation. We have |
|
| 60:00 | living things have a system in place kind of clean up mistakes. So |
|
| 60:07 | us, you know uh if you self cycle um we have a phase |
|
| 60:15 | being a replication occurs. It takes long time because we have lots of |
|
| 60:19 | and uh copy but there's a part this south cycle where it makes it |
|
| 60:25 | kind of stops before it goes any . If you remember your so I |
|
| 60:31 | remember it. Pro phase any phase phase tele face. I think I |
|
| 60:36 | those right in the right order. before it even goes into that |
|
| 60:42 | it stops and it goes, let's if there's any mistakes. Let's fix |
|
| 60:46 | mistakes before it goes forward. we're a pretty good system for |
|
| 60:51 | As do many other living things. so um because you don't want to |
|
| 60:56 | don't want to not fix these mistakes obviously it's gonna have implications. |
|
| 61:02 | Um from bacteria Archaea It's kind of rate that's higher ours is like one |
|
| 61:09 | one pretended 10th. I think we a pretty low just call spontaneous mutation |
|
| 61:16 | is just kind of a mistake. just happens it doesn't get fixed right |
|
| 61:20 | us. That's a really low rate bacteria. It's like one in 10 |
|
| 61:24 | the 61 in a million. Okay so because bacteria grow so fast you |
|
| 61:30 | you can see these changes in in know in the course of a week |
|
| 61:35 | so or less. Okay and so are even worse. They don't there's |
|
| 61:42 | no machinery to make them help repair . So the viruses are notorious for |
|
| 61:48 | lots of mistakes that don't get Hence really high mutation rate. Um |
|
| 61:54 | so what we're gonna look at here three kind of mechanisms of mutations. |
|
| 62:01 | and um these are very common. are like one base changes. Okay |
|
| 62:08 | can create these effects. Okay so point mutation means a one base |
|
| 62:16 | Okay and so here our top strand the um template strand uh that will |
|
| 62:26 | copied into Amarna. Right so we're look at changes to the DNA up |
|
| 62:30 | . Okay so this is our un uh strand. Okay so we transcribed |
|
| 62:38 | produce this protein. So this is normal quote normal non mutated strength. |
|
| 62:44 | and so we're gonna make a change right in that in that cytosine in |
|
| 62:52 | . And so when we do that can we're changing that to a |
|
| 62:58 | T. Okay to A. And then when that's transcribed. Okay |
|
| 63:05 | transcribed so that it contains an Now and not a G. |
|
| 63:10 | Okay so if you look at our there it is right there and we |
|
| 63:18 | a substitution. So you can Alright so here's our three or |
|
| 63:27 | So we're the same in those first amino acids. Okay. Not surprisingly |
|
| 63:35 | nothing has occurred where the change occurs after. So at the point where |
|
| 63:39 | change occurs now we see the Okay and so we changed it to |
|
| 63:44 | searing. So searing versus glycerine Alright. Searing. And so that's |
|
| 63:55 | call miss sense mutation, a different acids substituted for the one that was |
|
| 64:01 | . Okay. Um that can have effects. Okay so remember proteins fold |
|
| 64:10 | right into a very specific shape. so a change in video acid can |
|
| 64:16 | that shape change. And the protein anything it's all about its shape because |
|
| 64:21 | bind bind molecules as part of the and that of course it depends on |
|
| 64:27 | specific shape and binding and if you that you're going to alter its function |
|
| 64:32 | . And so altered amino acid by mutation depends on the chemical nature of |
|
| 64:40 | amino acid. Okay so a Syrian I seen there is some difference there |
|
| 64:48 | Syrian has has a hydroxyl group on . Um Glassine does not has a |
|
| 64:56 | I mean there are groups functional right? Glassine has an H. |
|
| 65:01 | Syrian, Oh h so it's not big a difference, but it could |
|
| 65:06 | enough. And so the function it depends on where where in the |
|
| 65:13 | . Right? So protein of course be hundreds thousands of mos is |
|
| 65:21 | Right? So if this is the , right? And this is maybe |
|
| 65:26 | active site, let's say right here the action is happening. Well what |
|
| 65:31 | um what if the substitution of the sense mutation occurred out here? |
|
| 65:37 | May not have much of an Okay, but what if it occurred |
|
| 65:41 | here? Okay. Be a huge . Right? So so location kind |
|
| 65:46 | has plays a part in here So so location uh chemical difference between |
|
| 65:52 | substitution, Right? It's something that's hydrophobic and now it's become something super |
|
| 65:57 | filic definitely could be a difference. those are kind of factors it depends |
|
| 66:03 | um Okay, so that's a You asked a substitute for a different |
|
| 66:09 | . Okay. Uh that's what happens um sickle cell, sickle cell anemia |
|
| 66:17 | red blood cell the the uh the um in in those individuals has a |
|
| 66:24 | base change and one amino acid change it changes the whole shape of the |
|
| 66:28 | and it doesn't work the same doesn't bind oxygen, like it |
|
| 66:31 | And so that's just do the one just like this. Okay um So |
|
| 66:39 | is the next one. So again is the normal molecules we're gonna change |
|
| 66:44 | there. Okay so we're going up So this is a nonsense mutation. |
|
| 66:51 | so um what happens is you form premature stop code on. Okay. |
|
| 66:59 | so um so basically again uh that's Can be lethal but there can be |
|
| 67:08 | chance for it's okay. Maybe you have 100% function. Maybe you have |
|
| 67:13 | between 2030, 40, 50 60 on location. So a misinterpretation, |
|
| 67:18 | cell has a chance to survive a mutation generally. No, those are |
|
| 67:26 | much lethal. Okay because you're basically the protein. Okay, taking a |
|
| 67:32 | of it off and in this case large chunk is taken off. |
|
| 67:36 | so the point is nonsense mutation. change occurs all right, this is |
|
| 67:42 | . T. Two and a. makes a you change down here. |
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| 67:49 | so we formed a premature you G. The stock code up basically |
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| 67:54 | shorten the protein and that generally is to be lethal. Can't function with |
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| 67:59 | . And so the third one here a frame shift. Okay, so |
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| 68:06 | again is another single base change. the other ones are substituting one base |
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| 68:14 | another, like the MS sense and , you're taking this base out and |
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| 68:19 | one in. Okay, one for . The frame shift is out is |
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| 68:26 | out completely. Right, so this um is being removed altogether. Okay |
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| 68:34 | so uh that means now we've um that point point so you can also |
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| 68:42 | just called the deletion when you take out, you can also shove another |
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| 68:46 | in there. Right? It's called insertion. Okay? In either case |
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| 68:50 | every point After that. Right? here. Right, so we have |
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| 68:58 | 123 and now we've substituted that and changed the media acid and everything after |
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| 69:05 | . You see how losing Alan Are not. These are the normal |
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| 69:11 | female. Allie and I seen. , so we're changing everything after that |
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| 69:16 | . Right? That's also generally lethal you're changing you're not cutting the protein |
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| 69:22 | but you're actually adding something different at point after the change. Okay and |
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| 69:28 | that typically leads to complete loss of . Okay so um the the so |
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| 69:37 | MS sense kind of have a chance survive that but for these two things |
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| 69:42 | . No. Okay so um let's I think it's probably a good place |
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| 69:51 | stop. We'll pick up with this next time, folks. Thanks, |
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| 69:55 | see you uh next week. Yeah. Mhm. Yeah. Uh |
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| 70:36 | you thinking that something in there is . Oh okay so you like |
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