| 00:00 | um start with viruses then. And so of course viruses encompass encompasses |
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| 00:09 | . Favorite virus. Our friend Covid is in this group. Um so |
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| 00:18 | mentioned discovery of viruses um briefly previously just centered around the smallness of |
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| 00:28 | Right? So filters we talked about um in the context of uh controlling |
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| 00:36 | uh filter sterilizing solution um that filter to effectively blonde viruses or not don't |
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| 00:46 | exist. But um and so the is really kind of based on that |
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| 00:54 | at this disease of effective tobacco plants just taking thinking that bacteria are causing |
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| 01:04 | outbreak in these plants. Because of this is right in the smack in |
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| 01:08 | middle of the whole germ theory and establishing microbes can cause disease. And |
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| 01:14 | that of course was an actual thought okay bacteria or some type of microbes |
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| 01:20 | this disease um a disease and tobacco and the uh when it looked at |
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| 01:29 | plants and just took disease plants and them just like you know approach populates |
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| 01:35 | that scheme um that the uh the plants would crush up, right? |
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| 01:43 | only they contain infectious agent, brush up, making the liquid paste of |
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| 01:49 | , so to speak. Take that , run it through a filter. |
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| 01:54 | well trap the bacteria on top We've got our agent right? So |
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| 01:58 | applied stuff on top of the filter out of trap, put it on |
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| 02:04 | plants, no disease. Right? the stuff that went through the fill |
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| 02:09 | applied that healthy plants boom. They the disease. So they knew they |
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| 02:14 | doing something super, super tiny. was, was not known to |
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| 02:19 | Okay. And could not be seen that point because we're talking, |
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| 02:23 | this is very early 1900s and uh, 19th century. So no |
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| 02:30 | microscope available and that's what it took actually visualize. And that's the actual |
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| 02:36 | Mosaic virus, which happens to be the small end of the spectrum in |
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| 02:40 | of size 29 years is about, the smallest large get rabies virus is |
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| 02:46 | in that size range. On the end of spectrum. I actually think |
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| 02:50 | a picture right here at the end the spectrum is but both big, |
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| 02:56 | uh, towards almost one micron in . So, you know, like |
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| 03:02 | micro and that's considered by microbes. , they have of course a size |
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| 03:08 | size range. Okay. And forms forms, shapes, whatnot. |
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| 03:13 | So, um, but you we've talked before about viruses of mine |
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| 03:18 | alive. Um, different arguments born that. Um, 16 when they're |
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| 03:26 | , they're definitely uh, synthesis, . But certainly when they're outside the |
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| 03:38 | as that here, these guys would okay. And this, sorry, |
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| 03:44 | area. Right. Are they, they alive in that state or |
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| 03:48 | But they can remain viable. There's viruses, I'm sure floating around |
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| 03:55 | and on door knobs and whatnot. uh, you know, are still |
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| 04:01 | are usually supposed to be replicated. . And so, um, even |
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| 04:08 | spans, you know, the capabilities they're capable of doing on their own |
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| 04:14 | spans the spectrum as well. So there's um what are called giant viruses |
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| 04:22 | greater than one of my right. these actually do have some properties such |
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| 04:28 | uh their own T. RNA is from in some cases. And so |
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| 04:35 | are thought to be maybe uh remnants what once used to be a |
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| 04:41 | Okay. Kind of degenerated. Um there's like uh smaller RNA viruses |
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| 04:50 | this thing. Right? Um maybe used to be part of a soul |
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| 04:56 | . So are a kind of became living entity. So it's uh a |
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| 05:03 | of speculation as to how viruses evolve we can see different forms like this |
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| 05:09 | maybe we can uh how ever But um they are certainly they've been |
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| 05:15 | right. There's no life form. don't think there's any life form on |
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| 05:18 | that doesn't have a virus that affects . Okay, so they certainly influence |
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| 05:25 | populations that's kind of what the next slides about. But before we go |
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| 05:30 | um like I said because they've evolved , you know with quote save their |
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| 05:36 | . They are on forever as Okay. And so um and like |
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| 05:43 | they evolved. Okay, they didn't and then host cells change their |
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| 05:48 | So it's back and forth, back forth. Okay. Um and so |
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| 05:53 | the longest time it was like that viruses I have no good. I |
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| 06:01 | do is infect cells and kill Right. What can be really about |
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| 06:05 | ? That can be good. Right the standpoint of uh from ecological stand |
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| 06:11 | population sciences. Right? Uh that can if you can, You |
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| 06:17 | going back to recall uh forget the but the aspect of college population |
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| 06:26 | et cetera, that um if you you have an ecosystem, one species |
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| 06:34 | dominant, right, then that kind limits the diversity. Right? That's |
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| 06:39 | only that's that's the one that's really that species and others are are not |
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| 06:45 | much. There's not a lot of . So you can't control population |
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| 06:50 | You know, that can lead to . So viruses can promote that in |
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| 06:56 | . Okay. And so this shows in aquatic ecosystems uh such as in |
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| 07:06 | oceans the role of viruses in controlling of allergy uh other um microbial life |
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| 07:17 | the sea. Uh and in doing virus films it and of course that |
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| 07:25 | cell becomes part of the decomposition, ? The dead organic material. And |
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| 07:32 | that provides better to those in the . Getting an influx of carbon for |
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| 07:38 | meta tropes influx of minerals and things your autotrophs. So it benefits that |
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| 07:44 | . And uh you know, just and of course the virus doesn't um |
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| 07:50 | its host species is, it's not wiping it out, not making any |
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| 07:54 | . Okay. It is because you that the members of the population that |
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| 07:59 | resist the virus. Okay. And but it is controlling numbers. |
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| 08:05 | So that's where you can see that more diversity current because no one species |
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| 08:11 | getting I remember the other and so get kind of quite kind of decomposition |
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| 08:21 | they can produce by infecting your species it and then providing these organic organic |
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| 08:28 | . Okay. So Because I certainly that I was you know studied microbiology |
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| 08:35 | little viruses. And so this is course has come to light in the |
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| 08:38 | 20 years or so. Okay. and even then it got there's lots |
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| 08:44 | virus going on that you're interacting with microbiome and and controlling pipe relations and |
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| 08:52 | . So um anyway so they do can do good things obviously they can |
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| 08:59 | bad things as we know them for last two years plus. Okay. |
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| 09:04 | but regardless um uh I guess like , it's never all good or all |
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| 09:10 | , it's gonna be expected. Okay um sorry about that feedback. |
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| 09:18 | let's look at this. Just it's same thing I just mentioned uh a |
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| 09:25 | ago. So let me see uh is specific to the uh something bacterial |
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| 09:32 | forms bacterial plankton. Um that's like the bacteria, et cetera. And |
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| 09:38 | on the right side, periodic viruses things like algae uh and simple microbes |
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| 09:44 | then the viral shut really just refers me as they get into the host |
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| 09:49 | reproduce killing the host. And then material um the composition the trident's call |
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| 09:58 | so break apart then that organic material for others. Um Now. |
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| 10:08 | so let's look at this question Right. So this will preview a |
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| 10:13 | bit about viral life cycle. But with any virus, right? |
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| 10:19 | begins unless this happens first. Will not happen unless we get this |
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| 10:26 | on initially. Okay, true. I think any virus uh fits this |
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| 10:35 | . So um while you're thinking about , any questions on the viral ecology |
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| 10:41 | anything? Yeah. How is it ? I saw the last life, |
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| 11:00 | signs of the virus park in in nature of its infection. Is that |
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| 11:04 | of Not necessarily? Oh, I know. Well, the reason why |
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| 11:16 | is so people Mortality rate of the is like greater than 50% upwards of |
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| 11:23 | . Okay. The reason for that more not because maybe the weird way |
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| 11:27 | looks, someone had the form. it really goes to this question |
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| 11:32 | Okay, let me let me ask this question. I come right back |
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| 11:37 | . Alright. I think I think would make sense. Um Alright everybody |
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| 11:44 | . Answer 12 seconds. 8765 frantically letters. Okay, and here we |
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| 12:12 | . Um Yes. So that's goes your suggestion. So recognition and attachment |
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| 12:20 | host surface module. That's where it . Or as So back to your |
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| 12:27 | about Ebola. So viruses we'll talk shortly have this um future about what's |
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| 12:37 | uh tissue specificity. So you can post range where a virus, how |
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| 12:42 | different posts can virus effect can affect animals, right? But within a |
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| 12:49 | host it can also have different tissue . Right? Cole mars infects your |
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| 12:57 | respiratory track salads, right? Um flu very similar. Uh Ebola has |
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| 13:06 | number of different self practical effect, is why it's so deadly in |
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| 13:11 | Um Epithelial cells and which like line vessels and things. And so you |
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| 13:18 | affecting those blood vessels begin to And Ebola is a disease that basically |
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| 13:23 | person that dies from it just fluids out of everywhere. You know? |
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| 13:26 | so it's very invasive and very because affects so many different cell types. |
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| 13:30 | why it's so deadly. Not so why it's yeah, it can be |
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| 13:34 | of weird. Big but it's really down to this aspect of being able |
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| 13:39 | affect different cell types is that Okay, so again it's all about |
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| 13:48 | , right? And uh the Okay. So remember that they're not |
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| 13:57 | not cells in the sense that we how we define cells. Okay. |
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| 14:04 | They certainly can evolve like self But they have the requirement to have |
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| 14:11 | host to do their functions. So they're small. Right? They're |
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| 14:16 | . and that small size means they you know they're gonna have a small |
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| 14:22 | . Right? We'll be able to for as many genes as probably most |
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| 14:27 | can. And so it's gonna So they relied for a number of |
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| 14:35 | , rely on the host for a of their functions. Okay. Um |
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| 14:40 | so the term obligate intracellular parasite. ? They're obligated. They must have |
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| 14:48 | um Like the obligate arab must have . Obligate anaerobic obligate intracellular parasite. |
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| 14:56 | parasitic lives inside the cell. Well at least for its reproductive part |
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| 15:01 | its life. Right? Um The . So at the most basic uh |
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| 15:09 | virus has a genome and protein That's a common feature of any |
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| 15:19 | That of course other things can be to that. See caps it is |
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| 15:25 | protein structure surrounding the genome which can D. N. A. Or |
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| 15:30 | . Single stranded DNA or or or stranded there's a whole variations. |
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| 15:38 | Um And so here we're just gonna through the basic life cycle. Um |
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| 15:46 | so what you'll see is pretty much to any virus but there's gonna be |
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| 15:54 | . So we're gonna see these variations we look at life cycles in the |
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| 16:00 | lecture. But of course all viruses cycle begins or doesn't begin unless they |
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| 16:09 | a particular molecular interaction with health surface . Things like different types of |
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| 16:17 | Glycoprotein white co lipids, these kinds things that are on the periphery of |
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| 16:23 | seven host. So and so that's they interact with And that begins the |
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| 16:30 | . Okay. And so from the . One of the things they need |
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| 16:34 | that things were asterisks. It depends the viral type. Some maybe some |
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| 16:41 | some kind of with them. Some . So uh is one of those |
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| 16:48 | . Okay depends on the RNA viral . Um Certainly the uh transfer |
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| 16:56 | So they need to do protein synthesis ? Um nucleotides of course to produce |
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| 17:04 | genome. Um The other thing is virus is pretty much lack metabolism. |
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| 17:13 | can't give them glucose and hope they're you know break that down the |
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| 17:18 | 02 and water. Right. They do that. They don't have electron |
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| 17:22 | system. And the things we equipped metabolism in usual cells again rely on |
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| 17:30 | host. Okay. And so the they rely on from the host is |
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| 17:34 | that to copy their genome and the proteins and assembly. Okay um the |
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| 17:44 | so following recognition attachment, recognition and then the viral genome centers and there's |
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| 17:53 | here. Uh The most number of you see are going to be an |
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| 17:59 | viruses. So we're looking at first look at bacterial viruses the more simpler |
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| 18:06 | speaking and the virus is a little complicated. And just about to pop |
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| 18:12 | head. Why don't you think an virus would be a more complicated life |
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| 18:18 | in the bacterial virus? Yes, , animal cells are just more complicated |
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| 18:26 | period. So naturally it makes sense the viral infection that's going to be |
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| 18:32 | complex in terms of its life Okay. Um Okay. And so |
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| 18:39 | again the variations we see here is animal virus system. The whole viral |
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| 18:45 | may enter. Okay. Um or of it. Uh bacterial viruses generally |
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| 18:51 | the genome enters. Everything else stays . Okay, so uh whatever the |
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| 18:57 | viral genome enters. Okay. And course it's about making copies of the |
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| 19:03 | . Uh You have to remember when looking at these life cycles. But |
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| 19:09 | endgame ultimately is the virus is made of particles. Infect new cells. |
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| 19:18 | , So what's going on in between ? Right? Basically what we're looking |
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| 19:23 | now in the cell, what's going is to that end to that |
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| 19:29 | Uh That goal may be immediate. some margin to come in, |
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| 19:34 | Make lots of viral particles get likely kill yourself. That's good. |
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| 19:40 | happened for others embarrassed. Right? so one of the things can be |
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| 19:48 | integrate with the host chromosome. So maybe the virus doesn't go, |
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| 19:51 | don't wanna make copies. And then gonna make particles and off we |
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| 19:55 | It's no I'm just gonna hang out the host chromosome and do nothing. |
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| 20:01 | , that's one strategy. Uh That's HIV uh virus place. Right? |
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| 20:09 | many others. Um So the even it does do that at some |
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| 20:18 | it's going to kick in viral Right? So basically the virus takes |
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| 20:24 | the cell and forming this with what's a replication complex making to sell a |
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| 20:31 | factory for it. Okay. And which is all about transcribing, translating |
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| 20:38 | genes. Okay. Into viral assembling all this material. Okay. |
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| 20:44 | then of course putting within the assembly , putting the right genome in |
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| 20:50 | Right. Whatever it may be. N A D N A. What |
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| 20:55 | ? Okay. So as I the basics of what you see here |
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| 20:59 | and of course exit the cell. basics of what you see are common |
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| 21:03 | types. We're going to see Variations different points. Different steps here which |
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| 21:10 | including exit some basically just lights to . They'll be like 200 or 500 |
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| 21:19 | viruses coming out at once and just and killing the cell. Um, |
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| 21:24 | come out piecemeal, you know, little bit at a time. |
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| 21:29 | And so the other thing to remember , you know, um the toll |
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| 21:36 | the host cell, Right? Host is certainly not having fun while that's |
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| 21:43 | energy being sacked from it. so um you know how much of |
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| 21:49 | toll taken on the host cell relates . Can you still very final and |
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| 21:57 | replicate because we'll see again variations where virus may infect. And just due |
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| 22:04 | kind of let me just make a at a time and exit. That's |
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| 22:10 | on the host host can survive that can still replicate albeit more slowly. |
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| 22:17 | . But the host cell does Okay. Um um but you know |
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| 22:24 | all depends on the bio type. , so we'll see different variations of |
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| 22:29 | . Okay. And each has kind their own own strategy for for |
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| 22:35 | Okay. Um any questions. So uh let's look at an effectivity. |
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| 22:44 | so I kind of mentioned this second contact. So host range. So |
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| 22:53 | can be a little bit confusing. there's host range and okay, host |
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| 23:00 | is how many different physical hosts can that rabies is obvious example. Rabies |
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| 23:08 | infect squirrels, possums, dogs, , humans, bats would happen. |
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| 23:14 | . Different hosts. That's host Okay so we brought in a rabies |
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| 23:21 | brought of course. Right, narrow measles, monks, common whole are |
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| 23:29 | narrow host range is okay. Um then the trope is um is within |
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| 23:38 | single host. So say a rabies um infects range can affect multiple mammal |
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| 23:48 | . Okay but then let's let's look this world that's a host for |
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| 23:54 | Okay so the squirrel then how many the tissue types can affect? |
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| 23:59 | rabies only affects infects nerve cells. . Um and then that's it |
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| 24:08 | Okay so that's gonna be a narrow tissue specificity. Think that way. |
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| 24:16 | . Uh cold, flu specifically invest the respiratory tract so broad as mentioned |
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| 24:25 | be Ebola infects multiple cell types in body. Okay. Um So just |
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| 24:33 | read every more time, repeat it more time host range. How many |
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| 24:37 | host bodies can effect? Right, vision within a particular host species. |
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| 24:49 | mean different tissue types. Okay. little bit different scope. Okay. |
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| 24:57 | Okay. And again, just to reader reader at this point. Right |
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| 25:02 | recognition. Right. While it's in state. Okay, viruses pretty much |
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| 25:09 | . Right? I don't even know going on. Okay. But once |
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| 25:15 | happens potentially then the infection cycle to . Okay. Um Do you notice |
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| 25:24 | ? Well you may or may not it but you notice it through symptoms |
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| 25:28 | whatever disease may be. Right. So virus structure. So captain right |
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| 25:39 | the viral so that the captain is of what are called capsule mirrors the |
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| 25:45 | units. And they can be and um these may have these geometric |
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| 25:52 | symmetrical viruses possess that. They can 2020 sided. Uh I guess you |
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| 26:01 | it. Um But it's not made uh it's made of multiple captured |
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| 26:08 | Kashmir's. Um But uh but there'll a handful of different actually different caps |
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| 26:17 | proteins. This one shows you three types. Okay. B. |
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| 26:21 | 12 and three. And they just those in a regular board. It |
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| 26:26 | mean that each. Um I've lost have a pen here, nope dang |
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| 26:44 | . Oh here we go. Okay if we see I'm sorry. We |
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| 26:52 | the different units here. Okay. one there's one there's one they're not |
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| 27:00 | a different protein. Right? So a three or four or five different |
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| 27:05 | that combined together. Okay. Again has to do with you know the |
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| 27:10 | of the violence. You know it it's not big enough to code for |
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| 27:14 | know, each individual unit. So comes up with a handful of types |
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| 27:19 | puts them together. Okay. So remember viruses from small gonna be efficient |
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| 27:27 | that in that way. Um The so you can so this is back |
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| 27:34 | here. So what you see here hepatitis a virus it's captured surrounding |
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| 27:41 | That's what we call a naked Okay so maybe viruses lack an |
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| 27:47 | That's what you see here. Okay here in the interior is the cab |
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| 27:56 | surrounding the genome. Okay. But all of this around it is an |
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| 28:00 | . Okay, acquired from the host . Okay. So enveloped viruses are |
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| 28:11 | going to be primarily if not exclusively the animal self variety. Yes. |
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| 28:20 | The animal soldier commonly will pick up envelope as an agent. The whole |
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| 28:28 | and then the potential memory track Okay. And that's what an envelope |
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| 28:33 | . Right derived from the host cell . The bacteria viruses. That doesn't |
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| 28:38 | because most bacteria had two cell It's not gonna wrap the cell wall |
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| 28:44 | . Uh so enveloped viruses that he'll as you see here, viral proteins |
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| 28:52 | insert into it. Okay, all little 90 things are viral proteins. |
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| 28:57 | envelope itself is host cell derived. , um Covid is like that. |
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| 29:05 | an envelope virus. Um Okay. so you often hear the term glycoprotein |
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| 29:13 | . You certainly do with the uh vaccine was produced against the specific spike |
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| 29:23 | in the the perfume of the virus the envelope. Uh certainly those are |
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| 29:29 | attachment. Okay. Um and so having a vaccine to the spike protein |
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| 29:39 | produced as a result will then bind then that disables the virus from binding |
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| 29:44 | yourself. The idea there. Um uh so you can see also. |
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| 29:54 | , so this is a naked virus this too. There's a naked |
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| 30:04 | Right? So you can have spikes it and not have an envelope. |
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| 30:07 | have those variations. Um the uh is viruses. Okay, these are |
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| 30:19 | of course. Okay. Um They be enveloped. Okay, you see |
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| 30:26 | here, this is Ebola wrapped. the helical envelope shape and then it |
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| 30:33 | an envelope around it. Um The mosaic virus as well is the |
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| 30:41 | This virus um tailed viruses are also complex viruses because they have kind of |
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| 30:54 | features. So you see they're captured viral structure that we're have seen several |
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| 31:02 | already. Okay, so that contains the captain the genome inside. |
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| 31:07 | You see all this other stuff. . You see this tube here and |
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| 31:13 | thing called the collar. Right. see all these structures here all that |
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| 31:18 | for the recognition and bonding Hill Hotel this this form right here. This |
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| 31:28 | will actually compress like a spring. compress and shoot the genome. You |
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| 31:35 | set up. So these types are viruses. It's very common for bacterial |
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| 31:41 | . The only thing going into the is the genome nothing else. |
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| 31:45 | That the virus disease that's that's not the case. The antivirus is kind |
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| 31:51 | a captured everything going in but not with bacterial viruses. Okay, |
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| 31:57 | it has to do with the cell that surrounds the bacterial cell typically. |
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| 32:05 | Okay. Asymmetrical. So you may at that and go, well that's |
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| 32:09 | a symmetrical circle. Okay, well actually kind of a more blondish form |
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| 32:16 | it. Okay, when you look electron micro graphs of like a few |
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| 32:20 | code I think in the same way a look round ish. Okay. |
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| 32:26 | not a perfect circle. Right. it can even change something change for |
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| 32:31 | little bit. So it's like to around it can even be someone oblong |
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| 32:35 | of blog. So that's what we asymmetrical types. In fact um this |
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| 32:42 | is an envelope virus um is kind a variation I guess of the of |
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| 32:52 | of the capsule structure I've been talking where it looks like this. Right |
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| 32:58 | we have the genome inside. you can also have this structure over |
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| 33:07 | . Okay. You see nuclear right? So that structure, it's |
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| 33:13 | necessarily a formal booking captured around but rather the genome itself is covering |
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| 33:21 | captured protein. Right? What they nuclear nuclear for nucleic acid caps it |
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| 33:28 | protein sometimes called captured protein. But genome itself has the proteins like found |
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| 33:35 | over it. Instead of being like like this encased in a capsule. |
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| 33:41 | GM itself is like studded with Okay, so that's not uncommon virus |
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| 33:48 | like that. And so does look that too. So you don't you |
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| 33:53 | see like like the box captured boxing side. You see the GM itself |
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| 33:58 | coated with protein. That's very easy Does that make does that make |
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| 34:07 | Um The uh I don't know when book doesn't go into that detail |
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| 34:12 | but it makes sense just to think because you're looking at it and go |
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| 34:16 | the capture that? Right. You really see it captured in this cross |
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| 34:19 | here, like like one of these . Okay. But you see this |
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| 34:24 | it's just proteins coding directly coding in genome. Okay, so let's think |
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| 34:30 | this question here. Alright. Uh reference to RNA RNA viruses. |
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| 34:36 | Depending on the particular RNA virus type GM could be used as a template |
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| 34:43 | what are the viruses are for most in the first article viruses, 30 |
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| 34:49 | are. The viruses tend to be one that's more you kind of have |
|
| 34:52 | wrap your head around. Okay. DNA viruses. DNA viruses we understand |
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| 34:58 | can understand better because they have a genome. You used to see that |
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| 35:06 | questions so far. What's an example a last week we talked about uh |
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| 35:22 | uh virus that herpes type viruses? bacteria viruses are those types? Yeah |
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| 35:37 | many other. Okay, so uh we'll we'll get more into definitely more |
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| 35:45 | RNA virus life cycles next time. it's good to kind of think about |
|
| 35:50 | now in terms of what he So just think of a R. |
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| 35:58 | . A template. What can you with that? Okay, um and |
|
| 36:10 | granted him and have all the information the question but we'll try it. |
|
| 36:30 | . See I got my app open God. Shut up. I'm gonna |
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| 36:36 | if I can answer the question. ? Yes. Yeah. Alright. |
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| 36:44 | I have 432. Alright, um majority is correct. All of |
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| 36:57 | All of the services depending on Right? You can have uh it's |
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| 37:05 | plus plus the virus. You can a minus RNA virus. You can |
|
| 37:15 | the virus that's a plus but uh reverse transcriptase. Okay. And um |
|
| 37:34 | out of space transcript case. so um we'll get into details. |
|
| 37:43 | we're gonna talk a little about at end but then more of it next |
|
| 37:47 | . Um So the nature of the and minus thing. Okay, that's |
|
| 37:55 | not good, I'm not using that of the virus. Plus minus |
|
| 38:00 | Is applicable to any time you're talking the gasses. Okay, it's an |
|
| 38:04 | assets thing. It's not a virus . Okay, it's like um remember |
|
| 38:10 | nature of graphic acids, right? D. N. A. You |
|
| 38:14 | have complementary strands. Right, so strands of D. N. |
|
| 38:20 | Are not identity one, is It's a complimentary copy. Okay, |
|
| 38:28 | so we refer to those two Other names are sense antisense. |
|
| 38:35 | Um we called for the plus minus . Okay, no I'm throwing this |
|
| 38:42 | now because you're gonna hear a lot it, you know, coming up |
|
| 38:46 | the end of that certainly next So we'll look through if you don't |
|
| 38:51 | already, we'll go through with what at. Okay, but because of |
|
| 38:56 | plus and minus strands connected act a differently, it can be templates for |
|
| 39:02 | different things. Ok, so in uh A plus RNA strand is a |
|
| 39:10 | for translation. Okay. And minus strand as a template for our M |
|
| 39:17 | synthesis. Okay and this guy in the chance to reverse transcriptase that's attempting |
|
| 39:25 | make DNA. So it was And D. N. A little |
|
| 39:27 | different. Okay um anyway so just it out, right, see if |
|
| 39:34 | sticks. Doesn't stick will make it in the in the next lecture. |
|
| 39:40 | because we're gonna we're gonna go over some more detail. Okay so here's |
|
| 39:45 | . Just throw it in just for . Uh if you want to throw |
|
| 39:49 | at it feel free. Okay. so has the envelope structure here. |
|
| 39:55 | , an example of that gino that the nuclear capsule, right? That |
|
| 40:02 | these the nuclear proteins directly on top the genome. You don't see the |
|
| 40:09 | captured on geometric captured form. You the captured proteins are directly stuck to |
|
| 40:15 | genome. Okay. It does have envelope. Okay and the spike |
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| 40:21 | Okay so plus RNA virus. So it can be a template directly for |
|
| 40:27 | make proteins. Okay and so that's something I'm gonna test john but just |
|
| 40:32 | know I don't really know this. covid is of course has an ancestry |
|
| 40:37 | it Back in uh 02 in Hong was the outbreak of SARS uh stands |
|
| 40:47 | sudden acute respiratory syndrome but never that spread beyond that area. You know |
|
| 40:57 | stayed there never spread um MERS is middle Eastern respiratory syndrome. It's it's |
|
| 41:07 | out in the Middle East. Um of course our covid is the most |
|
| 41:15 | version but they share that lineage. . All plus plus RNA. RNA |
|
| 41:21 | uh similar in many ways they all the bat the bat as the source |
|
| 41:31 | these originated. Um So uh the then in terms of what covid um |
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| 41:44 | onto host recognition are the receptors called receptors uh in LBO herself. So |
|
| 41:54 | think it's I haven't updated this uh the uh omicron version. I'm guessing |
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| 42:01 | is probably the delta version. Delta of wars in terms of symptoms causing |
|
| 42:09 | . And one of the main aspects its ability to buy. And so |
|
| 42:13 | be older cells of course you're in lungs. So severe forms of covid |
|
| 42:18 | cause uh severe pneumonia. Right Uh information of albi older cells is |
|
| 42:26 | problem the series because now you're impairing . That's what the shortness of is |
|
| 42:31 | of the center's covid uh relates to the self actually affects. And uh |
|
| 42:39 | course this happens. You get information needs to uh um swelling and fluid |
|
| 42:46 | the lungs and that of course leads the bad effects of pneumonia etcetera. |
|
| 42:51 | . Um but the omicron version isn't um deadly uh nor as serious in |
|
| 43:01 | of symptoms as a delta version is but but the omar conversion is more |
|
| 43:09 | than the delta version? What was working? Yeah, more more transmissible |
|
| 43:16 | marking tape is more transmissible but not as lethal. Um not a severe |
|
| 43:22 | with um So I guess I get now. So let's I did. |
|
| 43:31 | got like 234 before school started. uh three days I think was But |
|
| 43:37 | worst was I mean the worst was had they did have a fever like |
|
| 43:41 | and Low grade fever. And as called 101.4 or something like that or |
|
| 43:47 | . I forget anyway. That was worst. But that was about 80 |
|
| 43:52 | next day or so. But I think we all heard about covid |
|
| 43:57 | the timing. Okay. Somebody wants chime in with the covid story. |
|
| 44:01 | , we're good unfortunately. So it's . I'm not making light of |
|
| 44:06 | Um Any questions? Uh Yeah. . Uh Yeah, probably about actually |
|
| 44:27 | coming up that has numbers on. let me not speak. So I |
|
| 44:30 | upper range. Um Hold on. I have the number for the fact |
|
| 44:41 | giant viruses I mentioned earlier, that be upwards of more than a micron |
|
| 44:46 | . Those can have I think close the low end of what bacteria have |
|
| 44:50 | 500,000 base range. That's gonna be max. I think I would say |
|
| 44:54 | more like um must be the devil we are. Uh 10,000 bases for |
|
| 45:01 | probably probably about the average size. say this is your flu viruses. |
|
| 45:06 | has this amount zika virus we see . So you know of course if |
|
| 45:11 | look at the size ranges right? rabies virus on the low end like |
|
| 45:18 | nanometers in size. So it's probably have much less than this. Maybe |
|
| 45:22 | or so bases. Something like Place a little more because it can |
|
| 45:26 | more genome size wise. So this probably average I'd say in this |
|
| 45:33 | Um And so I do this and to you know, make the point |
|
| 45:39 | science, you know the genome size on how big the viruses. Um |
|
| 45:45 | so the other point is yes they dependent on the host to replicate. |
|
| 45:51 | . But they do of course carry that for virus specific proteins because there |
|
| 45:57 | certainly virus specific proteins that are part the process. Right? The captured |
|
| 46:02 | for example. Right. Um certain these proteins you see in the envelope |
|
| 46:08 | captions, Spike proteins and these kinds things. Right. So there's definitely |
|
| 46:12 | encoded um uh protein to the part the process of the life cycle. |
|
| 46:20 | Also uh you know some do some carry their own DNA for example certain |
|
| 46:27 | viruses. And so that that that certainly be a gene that codes |
|
| 46:31 | So it varies. But the point that there are certainly virus encoded |
|
| 46:36 | Um So the food virus. And in terms of genome so we looked |
|
| 46:42 | um so the Gm can be And D. N. A singular |
|
| 46:45 | stranded. Um Generally in either a form. Okay. Where's the double |
|
| 46:54 | or it can be like this. the flu virus is what we call |
|
| 46:59 | segmented segmented chopped up into four Okay it's actually eight segments I think |
|
| 47:08 | the flu virus. Okay now what can do for it is enable you |
|
| 47:16 | the combination combining segments of these. the thing is when viruses in fact |
|
| 47:26 | um you can have a current infection you can have two flu viruses affecting |
|
| 47:32 | same cell. Okay. And then can have accommodation for example of these |
|
| 47:37 | . Okay. That's the flu viruses next year of D. N. |
|
| 47:48 | . Is from their previous host. ? So has originated acquire uh |
|
| 47:55 | wild water birds and ducks. All . And then evolved into two domestic |
|
| 48:04 | chickens things. Okay uh domestic ducks geese and whatnot. And then then |
|
| 48:12 | slime like pigs. And so you the the humans once the virus you |
|
| 48:19 | see those remnants of those of that , you know of that chicken of |
|
| 48:26 | swine in in the flu virus. uh of course it's constantly evolving |
|
| 48:34 | Uh which is why there's a different shot every season because the flu virus |
|
| 48:41 | . Okay. Um thankfully it doesn't the um high mortality rate, |
|
| 48:50 | It's endemic of course. Um That's where covid is headed is into the |
|
| 48:57 | state. Like the flu. Um uh the segmented segmented you know is |
|
| 49:04 | of a different thing. We don't that a lot. And in fact |
|
| 49:07 | can't think of another example that flu that has this. Um But uh |
|
| 49:15 | I can't remember now but uh is question. Okay, so next next |
|
| 49:24 | things are are not we don't they're considered viruses. Okay. They're |
|
| 49:33 | right? So viral roids and primes . Are not viruses. Okay. |
|
| 49:41 | But they are virus life I Um So viral and prime are simply |
|
| 49:51 | , viral RNA. And that's his A molecule. That's it. No |
|
| 50:00 | nothing that it's an monitor. Pry ins a protein that's it. |
|
| 50:08 | else associated with it. Just a . No Cassidy noted paige acid. |
|
| 50:12 | a protein. Right? Um But fact this is the key. They |
|
| 50:17 | replicate themselves. They both get into host to replicate. Okay. Just |
|
| 50:22 | do it in kind of a weird more. So the crimes being kind |
|
| 50:26 | uh than virus, the viral roids plant, plant um infectious agents of |
|
| 50:35 | , uh fruits and vegetables, different very common to get infected with viral |
|
| 50:41 | . Uh I think the most studied the is the potato tuber spindle virus |
|
| 50:48 | it's called but it does affect other fruits and vegetables. Um To date |
|
| 50:54 | have not seen where in fact some of a human. Okay. Um |
|
| 50:58 | RNA molecules although not double stranded, can fold up and secondary structure they |
|
| 51:06 | complementary base pairing and that and actually structure is very important to its viability |
|
| 51:13 | folds in such a way to see to actually keep it viable. |
|
| 51:19 | so they can infect, It typically plants uh whether whether they may be |
|
| 51:26 | . Okay, because it's not easy affect the plant. Very really cell |
|
| 51:30 | . So a lot of uh plant , right, are typically carried through |
|
| 51:37 | factors when they infect plants causing disease plants. But uh anyway, so |
|
| 51:45 | are certainly a thing among uh certain and vegetables. They are small. |
|
| 51:51 | rely on the host on their primaries make copies of themselves. Okay, |
|
| 51:57 | uh you may not know different types RNA molecules can have on their own |
|
| 52:03 | activity. Right? So remember the ribosomes, ribosomes, the 16 s |
|
| 52:11 | of the small subunit um actually has activity. It's what creates the peptide |
|
| 52:18 | between amino acids. Okay. Uh so this I believe they believe has |
|
| 52:24 | activity as well. And um their is to I've seen where they where |
|
| 52:32 | interact with proteins affecting function but also expression of certain genes. Um beyond |
|
| 52:44 | , i it's not a whole lot about these. Um but you |
|
| 52:51 | it certainly is from an economic apparently it can devastate certain types of |
|
| 52:57 | . Um so that's about all I to say about viral. So the |
|
| 53:02 | takeaway with thyroids is infectious RNA nothing more than that in terms of |
|
| 53:09 | . Okay, now, lions are proteins. Okay, and so mad |
|
| 53:18 | disease. I'm guessing you may have about um back in the 80s. |
|
| 53:23 | was with the thing. Um not much. Not really here in the |
|
| 53:28 | but in Great Britain there was this raised you would see on the nightly |
|
| 53:35 | . They showed cattle and every now then that somebody's farm that were affected |
|
| 53:38 | this um you know, obviously causing neurological conditions, motor skills and things |
|
| 53:45 | that house falling down and whatnot. pathetic looking. But and that's you |
|
| 53:52 | how we would get, it finds . Um The term medical term I |
|
| 54:06 | for the disease. Spongiform encephalopathy. , so the pathology of the brain |
|
| 54:13 | uh spongiform uh is appropriate term because progress of disease. So the disease |
|
| 54:22 | very slowly okay in humans. Um it's um it ends up creating destroying |
|
| 54:31 | cells and in its place creating gaps the tissue or nerve cells used to |
|
| 54:39 | and disappeared. Okay, sort of holes and brain tissue giving the brain |
|
| 54:47 | a very spongy consistency. That's that spongiform. So you studied this I |
|
| 54:54 | initially studied this in uh and sheep think is the first study this and |
|
| 54:59 | saw of course the pathology of the tissue uh in this forum um the |
|
| 55:07 | human, so scrapie is like the and sheet humans they call it Forestville |
|
| 55:13 | disease. Uh I guess you can get it from eating practice of eating |
|
| 55:20 | infected brains of humans. So cannibalistic . Uh I think I've seen been |
|
| 55:28 | to have have this as well that's kuru K. U. R. |
|
| 55:33 | . Um In any case, what this thing all about? Well number |
|
| 55:40 | we have the normal formulas in our brain cells. In fact it actually |
|
| 55:48 | in very many types of cells but prevalent in brain cells. And still |
|
| 55:55 | this day, I have not seen exact function of a pinpoint. |
|
| 56:00 | I've seen most often that may be have something to do with operative |
|
| 56:06 | Weird but that's what I've seen. The normal form is needed. Okay |
|
| 56:14 | um what happens is it becomes an form. It's all about changing the |
|
| 56:20 | structure approach really is what's happening. . And the prion form, The |
|
| 56:28 | is what we call the misfolded misfolded form. You can see the contrast |
|
| 56:34 | the tertiary structure between the two types so the the abnormal form um when |
|
| 56:41 | binds to a normal type, it the shape into an abnormal shape as |
|
| 56:48 | see here. Right? So this through the binding as we has assumed |
|
| 56:57 | prime shape. Okay, you've got chain reaction again, slowly gradual |
|
| 57:04 | Not instantaneous over time you get aggregates these animal forms. They think they |
|
| 57:12 | even like buying together become form like type of thing. Okay. And |
|
| 57:20 | gradual accumulation of these these the death nursing. Okay. Um be surprisingly |
|
| 57:29 | very resistant to various treatments. Physical chemical treatments really have to really if |
|
| 57:36 | know you're getting weak aspect of the which don't worry about the right number |
|
| 57:40 | cases. People died of priority to U. S. Is like |
|
| 57:45 | Okay so that's not something you need worry about but just for grins. |
|
| 57:50 | you had to study the head. cook the hell out of it you |
|
| 57:54 | ? Very very well done. Apparently it's very resistant attempt as well |
|
| 58:02 | maybe because the way it folds up sure what to do with it. |
|
| 58:07 | There is and so you see in cross section of diseased tissue the these |
|
| 58:14 | the holes basically the where neurons used be plaques. I think they also |
|
| 58:19 | these things plaques as well so um course accumulating those and this is a |
|
| 58:24 | spongy kind of brain and you don't a spongy brain. Okay. Unless |
|
| 58:28 | absorbing knowledge right now that the brand gonna absorb knowledge holding it. Um |
|
| 58:37 | and this just shows a little cartoon of how the red the green are |
|
| 58:43 | normal prime proteins and the red Bad words that are forming and they |
|
| 58:48 | obviously accumulating in this neuron. Okay and then they can they can migrate |
|
| 58:56 | other cells and start the cycle in cells. Okay um Any questions. |
|
| 59:06 | so prions are proteins that are Vai roids. RNA molecules are |
|
| 59:12 | Neither do we consider them to be they're just kind of these unique virus |
|
| 59:18 | things. Okay so here's a So we're gonna kind of wrap up |
|
| 59:28 | classifying viruses. Okay. And having gone through the structure of viruses. |
|
| 59:38 | well differentiate viruses with different things we've we've already seen now you can maybe |
|
| 59:44 | pacify them by. Okay I'm sure can come up with a number of |
|
| 59:49 | things but not everything we'll sit. you from. Okay one down |
|
| 61:04 | Here we go to one. You be able to do a carbohydrate fermentation |
|
| 61:16 | I. D. Purposes. Okay viruses don't do that. Okay um |
|
| 61:24 | you know hypothetically you could use all except for B to identify and you |
|
| 61:31 | they are used but uh kind of standard is the Baltimore classification he's the |
|
| 61:41 | of of co discovery of the HIV retrovirus. Um so what this is |
|
| 61:52 | based on is a genome type and route to get to expression of the |
|
| 62:04 | of RNA the protein. Okay how it get to that point? So |
|
| 62:09 | group one and two R. N. A viruses double stranded, |
|
| 62:13 | stranded respectively. That I think is of easy. Right. It's easy |
|
| 62:19 | to wrap your head around because that's you're used to seeing. Right. |
|
| 62:22 | transcribed to RNA M. R. . And then translating programs I think |
|
| 62:28 | pretty easy to grasp. Right? there aren't a viruses and there are |
|
| 62:32 | variations. And so here's the key this box. Okay so plus |
|
| 62:41 | N. A. Is a plus RNA. It contains the coding information |
|
| 62:51 | be translated into approaching. Okay. And so we're looking at RNA viruses |
|
| 63:03 | not all but most require this in RNA dependent RNA polymerase. It's a |
|
| 63:12 | enzyme. Okay we don't have that do other life forms because um what |
|
| 63:23 | of memories do we have? No we had we just have it's called |
|
| 63:34 | it's called R. N. No it's cold D. N. |
|
| 63:40 | . Dependent on income race. That's we've got D. N. |
|
| 63:45 | Dependent are because our our unemployment is our D. N. A. |
|
| 63:53 | . Approach. Right? So we DNA dependent not are we don't copy |
|
| 63:59 | is into our. Okay um but three groups of RNA viruses do |
|
| 64:07 | Hence they have a gene for that ? That they're gonna get it from |
|
| 64:13 | host. Okay um Okay so group 4 and five. So with the |
|
| 64:26 | threes which have double stranded RNA they're have a plus and minus strand. |
|
| 64:32 | remember so you can see that plus relationship is here as well. |
|
| 64:38 | D. N. A. I it's about time you take acid. |
|
| 64:43 | ? It's not about the virus. take acid that's why we make the |
|
| 64:46 | minus designations. Okay? Um So the double stranded RNA bars it's got |
|
| 64:53 | has one of each. Right so we can copy the M. |
|
| 65:00 | A. We can copy to transcribe miners stranded strand. And uh we're |
|
| 65:07 | . Okay then we can use that translate the um now the other two |
|
| 65:13 | . All right have um one has plus are in a group four group |
|
| 65:20 | minus RNA genome. Okay so whenever copy a strand is going to make |
|
| 65:29 | complimentary copy, we know that. so plus copies into a minus and |
|
| 65:34 | into a plus. Okay so for plus strand you may be thinking okay |
|
| 65:42 | a plus Arnie a virus with this . Okay I know that that I |
|
| 65:49 | from this box that that can act an M. R. I can |
|
| 65:55 | proteins out of that. Okay so don't need to copy that at |
|
| 66:03 | I got a genome that can be directly to proteins. I go to |
|
| 66:06 | hotel boom. Why do I need make a bunch of copies of |
|
| 66:14 | Why? Thank you. Ever went in the first line and we talked |
|
| 66:21 | viral replication? Think of the end the indian for viruses. What? |
|
| 66:29 | lots of little viruses? Right. gonna be in each one of those |
|
| 66:33 | viruses copy of the deal. So about making stuff so that that virus |
|
| 66:41 | is gonna make lots of copies of R. N. A. And |
|
| 66:46 | has to happen that way. Believe if it could go if you can |
|
| 66:50 | a bunch of the copies of that that. Of course it would. |
|
| 66:58 | it can't it just doesn't happen. It has to go through. It's |
|
| 67:04 | the rules of nucleic acid base Alright you can't it doesn't work that |
|
| 67:08 | . So they have to go that . Maya's then crappy got into a |
|
| 67:14 | . So that's the thing you got wrap your head around. Right? |
|
| 67:20 | so but it's just following the rules basement. It's all it is. |
|
| 67:27 | can work it out for yourself and a paper right? You're not gonna |
|
| 67:31 | okay A U. G. We're gonna copy that into A |
|
| 67:39 | G. C. No the copy U. A. C. |
|
| 67:47 | Okay that's that's all that's going Nothing magic. Okay but for the |
|
| 67:53 | that is a single stranded RNA virus the hoops that has to go |
|
| 68:00 | Okay so um that's why you see kind of seems to be back and |
|
| 68:06 | . What's this all about? That's why. Okay so for the minus |
|
| 68:11 | the virus it can make copies of And boom it's got M. RNA |
|
| 68:16 | now been translated protein but it's not . It's not done because why in |
|
| 68:25 | end game to package into all the particles. It's going to make so |
|
| 68:33 | have to make copies of that. hence we go and draw. So |
|
| 68:38 | gonna because I'm ending where the RNA ends. That's why I'm not |
|
| 68:42 | it. But what will happen is will then go into minus R. |
|
| 68:47 | . A. With another round of . D. R. P. |
|
| 68:51 | short. Okay. Only because it those guys to stuff into all the |
|
| 69:00 | viruses is gonna make right? So remember the endgame, right? But |
|
| 69:05 | fact the end game is gonna be lots of viral particles. Each one |
|
| 69:10 | is a genome and plus a bunch other stuff. So that's why it |
|
| 69:16 | does this this way. Okay. And so the last one here is |
|
| 69:23 | . That's the oddball. Right? they use their RNA as a template |
|
| 69:27 | make DNA. Okay, reverse transcriptase that then uh then use actually um |
|
| 69:39 | DNA polymerase to make the other strength strength. So here, again, |
|
| 69:48 | , base pairing rules. Right? is A plus R. N. |
|
| 69:51 | . Carbon into a minus D. . A. Right, same, |
|
| 69:58 | . Right? That's why it happens way. Whether it's RNA RNA, |
|
| 70:01 | DNA or anything. And then um finally it would transcribe the DNA form |
|
| 70:10 | make the M. R. Transit. So again, it's all |
|
| 70:16 | in this classification scheme. It's all how do we get two here? |
|
| 70:25 | , because of course that's important you get synthesized by a protein, |
|
| 70:29 | Because remember there's two things going right and just keeping it keeping the |
|
| 70:34 | structure. Right? We got to that. Alright. Captured any proteins |
|
| 70:43 | make that. And whatever else is knobby things. Right. Maybe in |
|
| 70:48 | like this. Okay. And then gotta stick a genome it. |
|
| 70:53 | So all that happens in the course a viral infection. You're gonna make |
|
| 71:00 | that stuff together. Which is why have to the virus. And then |
|
| 71:06 | you go through these different staff, . Okay. Um, so, |
|
| 71:17 | , real quick. Okay. Don't this. Table number one. |
|
| 71:23 | Just threw it in just to show really talking about RNA viruses at the |
|
| 71:28 | of a lot. So many viruses familiar with are in those two |
|
| 71:33 | Right? Your covid, your west , which is endemic in this |
|
| 71:40 | Uh, poliovirus, measles and mumps rabies flu. All all your |
|
| 71:47 | Alright. Are in the among the RNA viruses. Okay. All |
|
| 71:53 | You guys have a lab something. do others continue studying others. I |
|
| 72:01 | . See you next |
|
