| 00:17 | Okay folks, uh let's go and started. Um Mhm. Yeah. |
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| 01:04 | . Uh huh. See, so see the schedule. I put the |
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| 01:06 | up that takes us through the second . Okay, so the next week |
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| 01:14 | , 10. So week nine spring , no classes, of course. |
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| 01:20 | so a couple of things to point . So of course I'm starting at |
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| 01:25 | today. Um the flip class, one of those, you know, |
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| 01:31 | of questions. The The video for content is up and it's in the |
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| 01:39 | flipped class folder. So take a at that beforehand. Um it's only |
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| 01:46 | be the 13th part one material. , so we'll do that next |
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| 01:51 | It's gonna extend over and I can half a class over two periods. |
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| 01:57 | , so um so this section, unit is Three chapters, viruses. |
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| 02:06 | then really 13:14 is metabolism heavy. , so um if you've already looked |
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| 02:17 | , don't be um Um scared I maybe, I don't know by the |
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| 02:23 | and 14 material, you'll see probably of pathways in the book. And |
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| 02:27 | different and time reaction. So you're expected to memorize those things. Um |
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| 02:33 | definitely look at your lecture notes as going to the book. I take |
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| 02:40 | material is more, the metabolism is in in stages. The process is |
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| 02:46 | , like causes slow respirations more like . But was in what comes out |
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| 02:49 | not all the individual reactions. So , just give you a heads up |
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| 02:55 | that. Um Okay, so exam will be available on costs of Wednesday |
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| 03:02 | friday. So do I look at . Um there is no answer key |
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| 03:08 | everybody has a different combination of questions I'd have to have like 200 different |
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| 03:12 | keys. Okay so do look through you can't you'll you'll actually right up |
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| 03:18 | top look at a handful of questions go oh yeah that's what the answer |
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| 03:22 | . Okay so um but there may some that you are still confusing so |
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| 03:28 | let me know. Okay um so that but do before you if you |
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| 03:34 | to meet fine not a problem you to office hours if you want to |
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| 03:37 | another time because the officer doesn't fit schedule fine too. Um But do |
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| 03:44 | at the exam first and before we so that you have your best shot |
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| 03:50 | um you learn more that way I I'm trying to figure out on your |
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| 03:54 | of course. You know you have options. You have to you don't |
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| 03:57 | have to look at it again because not, the final exam is not |
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| 04:01 | in this course. Right? So each exam covers a separate unit. |
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| 04:07 | um you know you could just not I don't care at all about example |
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| 04:11 | , I'm just gonna move on. or you know I think it would |
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| 04:14 | who be to look through the questions . Um And uh hell there could |
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| 04:19 | a just a flat out mistake I , right? So even for that |
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| 04:24 | , just just look through it if is an error of course and obviously |
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| 04:28 | credit for that. So um so about exam, what the exam |
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| 04:34 | About What I usually get? It's I try to aim for like in |
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| 04:38 | 69, not 69, 68, range right? Somewhere in there And |
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| 04:43 | range was actually about 15 iron and little bit more than that. So |
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| 04:50 | individual exams aren't curved, but the grade and the course can possibly be |
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| 04:56 | . Okay? Um It all depends if the curve benefits, you're not |
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| 05:00 | curves can go two ways, They can they can lower the letter |
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| 05:07 | cutoffs, right? Which is what want, right? Rather than a |
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| 05:10 | and above is a Uh C well it was 60 and a buck |
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| 05:16 | the C -, right? That's preferable, you know, beneficial curve |
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| 05:22 | you. But if it takes a to get to 16 minus an 80 |
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| 05:26 | get the c minus and above, you probably don't like that. |
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| 05:30 | so um I only curve if it you. Okay, So we can |
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| 05:34 | more about that as we go But uh and I will always gonna |
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| 05:40 | closer to the end, but for just uh if you didn't mean that |
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| 05:46 | meet expectations, we think maybe how studied uh if you want advice flash |
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| 05:52 | on that process. Look at the exam, the first day lecture I |
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| 05:59 | about 2015 20 minutes. And then talk about how to study. So |
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| 06:03 | that if necessary but certainly um uh by office hours. Have you |
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| 06:10 | And we can certainly talk about it . Okay. But uh first thing |
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| 06:16 | you know once the exam is take a look at it, see |
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| 06:20 | you got wrong. See if you figure out what the answer is. |
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| 06:23 | not absolutely let me know, email by. Officers try. Um So |
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| 06:31 | know, you should have hidden to amnesia, right? Because what you |
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| 06:39 | well or good or in between on exam one, just you know, |
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| 06:44 | going to the next thing. Focus exam two. I would recommend that |
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| 06:50 | you didn't meet expectations, don't do not repeat identically what you did |
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| 06:55 | study for the first exam, you have to change up the answer. |
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| 07:00 | you didn't do well in exam one not I'm gonna try even harder. |
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| 07:04 | . It's not about that. I'm sure you tried hard enough studying |
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| 07:08 | exam one, but don't try harder a method that got you not very |
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| 07:14 | results. That's the point. You can try harder fine. But |
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| 07:18 | you're trying harder with the same it's gonna be the same grade. |
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| 07:23 | ? Maybe worse. Right? So it up to my advice, |
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| 07:28 | And uh that's how to change it into what that's what that 20 minutes |
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| 07:32 | so on. That first day lecture about. Okay. So anyway, |
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| 07:37 | leave it at that. We have as I said the third time. |
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| 07:42 | at the exam and it's open. ? See what you missed to see |
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| 07:44 | you uh if you have questions, me know. All right. |
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| 07:48 | this week we're back to stuff being again. Right. So we got |
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| 07:52 | quiz uh this week. Um And then we have smart workers do |
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| 08:00 | It's the first stuff we're talking mainly about viruses. The part |
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| 08:04 | Um Let's see. Next monday Alright. So next monday is the |
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| 08:11 | class. Okay, so that video up. So do take a look |
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| 08:14 | that. Okay, so main things week. Blackboard please. Smart |
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| 08:20 | Okay. And looking at exam one it's available. Okay. So um |
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| 08:27 | chapter six Okay. Is um broken The way I've split it up is |
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| 08:36 | one described in terms of the viruses somebody could find them. Um What |
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| 08:43 | some of the features of viruses? How do we classify viruses? |
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| 08:48 | what are some of the important structural ? And that's part one. Part |
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| 08:54 | will cover most of that today. two is um the life cycles of |
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| 09:00 | as you will see. Well, present. Kind of a generic Here's |
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| 09:04 | viruses, viruses replicate. Um But point out how there will be numerous |
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| 09:13 | will see of different steps as we through virus cycles next time. |
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| 09:20 | So it's um discovery of viruses I that we talked about this before. |
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| 09:28 | So it's all about their discovery is about their size. Okay. Because |
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| 09:32 | that viruses are on the Lower in of sizes, right? About the |
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| 09:39 | nm. um .02 microns to about nearly a micron. So these aren't |
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| 09:45 | you can see with a light Okay. So I have an autopsy |
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| 09:52 | . Uh they were studying the tobacco will not they didn't know they were |
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| 09:57 | virus but they were studying the virus caused causes tobacco, tobacco disease and |
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| 10:03 | plants. Okay. And the what it does is it creates. |
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| 10:09 | so of course a healthy plant has green leaves, you know, uniform |
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| 10:15 | . Uh a disease plant from one these viruses has like a splotchy color |
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| 10:22 | a yellow spots all over it. , Security is a sick plants can |
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| 10:28 | as well. Um, but so was of course in the early part |
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| 10:33 | the century, growing tobacco was a it still is but but it was |
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| 10:40 | important and uh trying to study this was this was during the period of |
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| 10:47 | knew the coke and the germ theory disease was known and established by this |
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| 10:52 | . And so of course they well it must be some sort of |
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| 10:54 | bacterial micro, right? That's causing . And so using, you |
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| 11:00 | coach postulates, right that only diseased will carry the microbe, right? |
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| 11:06 | plants do not. If we isolate microbe and applied to the healthy |
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| 11:11 | healthy plants should come down with Right? We've gone through this |
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| 11:16 | So, um, so they took plants crunch them up, right? |
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| 11:21 | like a liquid paste, if you . Then they of course the filters |
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| 11:28 | available at this time. That would microbes in the bacterial size range. |
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| 11:33 | so they said, okay, let's that liquidy paste through the filter. |
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| 11:38 | trap the microbes on top. We'll that stuff to plant a healthy plant |
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| 11:43 | will find that they come down this and figured out the cost. |
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| 11:48 | They did that. And it didn't one of the healthy plants. They |
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| 11:52 | this stuff to ever got sick. only when they looked at the I |
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| 11:57 | know what properly to do it. they said, well, let's look |
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| 11:58 | the stuff that comes through the right to infiltrate, that when they |
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| 12:03 | it to healthy plants, then they this disease. They knew they were |
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| 12:08 | with something uh, out of their that was really small. And they |
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| 12:14 | no idea about, Okay. And wasn't really until about 30 years later |
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| 12:19 | into the micrografx of of that particular that causes this disease. Tobacco mosaic |
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| 12:25 | . It's only small, end size . Um, it uh, it |
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| 12:30 | an electron microscope to see it and wasn't developed until a few decades |
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| 12:35 | And they asked the crystalized it and a picture of it. So, |
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| 12:42 | , of course viruses um, as talked about before, require folks. |
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| 12:48 | right. They there's there's no life on this planet that likely doesn't have |
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| 12:56 | sort of virus that infects. And um, of course, you |
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| 13:02 | , viruses viruses have been with us for six million years. Right. |
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| 13:07 | so, uh, they've evolved with . Um, they can effect it |
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| 13:12 | the longest time. You can always this stuff. There's another dragon. |
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| 13:17 | there was really no positive benefits of that were spoken. You know, |
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| 13:22 | I was studying this stuff and even to about maybe 20 years ago, |
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| 13:25 | years ago. Okay. Uh all new viruses could do was cause |
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| 13:30 | Okay. But it's come to light they do have important ecologically. |
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| 13:35 | Even in our own gut, the , the virus isn't there kind of |
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| 13:40 | populations of microbes in our guts. they do have an influence and |
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| 13:46 | the because of, you know, microbes are found everywhere. So are |
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| 13:50 | because they look, they require those that are out there. Okay, |
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| 13:56 | um, size range I mentioned, talk about at the end likely next |
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| 14:07 | . Um, what are called giant . So these actually exceed A micron |
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| 14:14 | a micron 1.5 microns. Um and have a big enough genomes to encode |
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| 14:22 | certain genes um involved in protein Not the full complement but parts of |
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| 14:28 | . And so it's believed that maybe giant viruses were once cells that kind |
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| 14:33 | degenerated maybe into a more Republic Um small viruses. And we talked |
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| 14:41 | that are RNA viruses like covid and virus. Um it's not that maybe |
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| 14:47 | small nucleic acid pieces started out as as a genome and science themselves that |
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| 14:52 | evolved into this form. So there's kinds of speculations of how the virus |
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| 14:58 | evolved. We see kind of different of viruses this way. Okay. |
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| 15:04 | now the uh ecology, so just briefly a second ago about you |
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| 15:13 | that there are positive benefits for Okay, so in controlling populations, |
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| 15:19 | . So the virus infects a It can potentially kill it eventually. |
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| 15:25 | in doing so that being that has died as the result of a viral |
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| 15:31 | becomes detritus. Right? The complete becomes those elements of that entity now |
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| 15:39 | available to others in the ecosystem. And so the the in aquatic |
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| 15:47 | they've studied this in marine aquatic studied this, how viruses impacted different |
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| 15:53 | of um algal populations, Brazilian populations um they don't wipe out the species |
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| 16:03 | infect. Right? That would be of counterproductive. Um almost completely because |
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| 16:11 | because the host itself does evolve and can have types that become resistant. |
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| 16:18 | ? And the virus must have you don't be able to be able |
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| 16:20 | infect those new uh newly resistant So it's back and forth constantly between |
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| 16:28 | and them. And um but in so, right. So remember kind |
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| 16:32 | remember ecology, right? And that that have a single dominant species, |
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| 16:42 | ? That that is most abundant, ? Because they have a lot of |
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| 16:47 | in those kinds of ecosystems. For the dominant species kind of overrides |
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| 16:53 | else and other other species are only smaller proportions and not as diverse. |
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| 16:59 | , if you can kind of balance out there. All right, then |
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| 17:03 | can have more diversity. And that's viruses can do in ecosystems is too |
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| 17:08 | controlling these populations, create more And so this here is a |
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| 17:14 | So the viral Schunk refers to um see here is that portion that when |
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| 17:24 | kill their host cells, that material , you know, the composer becomes |
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| 17:29 | of the material that others can So uh broken down organic matter. |
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| 17:35 | ? So of course uh others and can can certainly use that. So |
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| 17:39 | can contribute to that. Okay, whether it's affecting uh on a trophic |
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| 17:46 | cells or head atrocious. Right. so as a result we create a |
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| 17:52 | and potentially more diversity in the which is good for everybody. |
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| 17:57 | Um so we um and this shows again they picture of this process and |
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| 18:06 | you see in the viral shunt how try this forms organic, that's organic |
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| 18:14 | is basically just dead organic material Right? And so that can then |
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| 18:19 | others thriving ecosystem. So things like funding is higher level higher if you |
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| 18:25 | outs in these ecosystems, uh plenty nutrients and enables them to grow and |
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| 18:30 | others to grow. Okay, so Alright, so let's look at this |
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| 18:37 | here. Okay, this we're gonna a little bit about just a basic |
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| 18:43 | life cycle. Okay. And uh matter how complicated or maybe not so |
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| 18:50 | viral cycle is there's gonna be some all of them. Okay, this |
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| 18:57 | kind of hinting at one of those features that are gonna be part of |
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| 19:03 | viral cycle. Okay. No matter type of virus. So let's see |
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| 19:09 | we get here. So unless unless process of the viral life cycle occurs |
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| 19:16 | , it will never reproduce. So of these are part of in viral |
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| 19:25 | cycle as we'll see. But one them has to curdle for any of |
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| 19:29 | others. Yeah. Mhm. Okay. Timer's on, while we're |
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| 19:51 | here thinking about this. Any questions ecology. Thank you. All right |
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| 20:08 | and down. Mm hmm 543 stragglers in. Mhm. Okay. It's |
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| 20:21 | 108 account. Okay. So if you answered. D um you |
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| 20:28 | correct. Okay. So it is it all begins or ends really with |
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| 20:35 | . The virus effect recognizes molecules on periphery of the cell and that's what |
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| 20:42 | looking for and like a lock and in the lock fits or it doesn't |
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| 20:48 | the virus effects or it doesn't. . And if d doesn't curl well |
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| 20:53 | we'll get um replication of host We'll get translation of all proteins. |
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| 21:02 | of Syrians will get maybe this is maybe not all viruses go to the |
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| 21:07 | but maybe it will. Okay. possibly. Okay. Point is all |
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| 21:11 | these will occur. And of course will only occur if d occurs |
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| 21:17 | Okay. And so looking at basic . Okay, so the point here |
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| 21:24 | that viruses aren't cells as we Okay, so there's a very specific |
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| 21:31 | . Um a cytoplasmic membrane lipid bi in closing a cytoplasm that may have |
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| 21:37 | nucleus. If you're you carry out , toyed with their bacterial Procardia type |
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| 21:44 | . Things like that. They self on their own. They can take |
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| 21:48 | nutrients and metabolize uh they can So they don't viruses don't have all |
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| 21:54 | features. Okay. They're certainly not as we know them. But surely |
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| 21:59 | can evolve. All right. They metabolize like you can't give a virus |
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| 22:04 | and hope it's going to be you , get energy from it. It |
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| 22:07 | work that way. Okay. But do have the most basic structure of |
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| 22:13 | virus. Okay. Is the protein or the capsule that you see here |
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| 22:19 | and closing a genome. That is the basic structure for every bias. |
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| 22:26 | . Now, of course there's going be variations of that as we'll |
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| 22:29 | But at the most basic common structure it captured surrounding genome. Right? |
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| 22:34 | genome can be D N A R A double stranded single strand different |
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| 22:41 | The units of the capsule itself are capsule mirror units? Okay, now |
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| 22:48 | basic uh life cycle will go through as we go through next time you're |
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| 22:57 | to see different variations of certain Okay, so as mentioned, it |
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| 23:03 | and ends with recognition. So what's recognizing? Well, it's gonna be |
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| 23:07 | on the periphery of the cell proteins the surface. Glycoprotein like olympics, |
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| 23:13 | kinds of molecules. Okay. Um where the virus has evolved to be |
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| 23:19 | to bind to bind to it and in entry. Okay. Um once |
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| 23:26 | recognition occurs, okay, it may end up using one or more of |
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| 23:32 | um components from the host. So asterisk ones. DNA plummer plummer is |
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| 23:39 | . Okay. Because that depends on viral type that's infected. Right. |
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| 23:46 | RNA virus for example doesn't need DNA usually there's an exception of that, |
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| 23:52 | we mentioned, but most do not the because they have an RNA genome |
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| 23:58 | others that are being a viruses may may not have it some some carrying |
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| 24:04 | some don't uh Arnie Primaries, some use the host that may have their |
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| 24:09 | . Okay. But certainly ribosomes Trn nuclear types. They'll all need |
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| 24:17 | That's all a part of copying viral and making proteins. Okay. But |
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| 24:24 | , they lack of metabolism in complex . Like we have. Right, |
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| 24:29 | don't have black calls since they don't so respiration and these kind of |
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| 24:33 | Okay, so um infection. So recognition. This is a point again |
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| 24:40 | there can be variation. Right? could be that the capsule with the |
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| 24:45 | enters itself completely. Right, bacterial , it's only really just the genome |
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| 24:52 | everything else stays outside. So variations and how it enters it can |
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| 24:57 | as well. Okay. Um of one of the first steps is to |
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| 25:03 | copies of the genome. Right. one thing you have to remember is |
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| 25:09 | we go through different life cycles, might be thinking, well why is |
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| 25:12 | doing that? And and this is I don't get that. Right. |
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| 25:15 | I always think of the endgame, . A cell coming in and many |
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| 25:21 | , right, Being assembled and then . Right. That's that's that's what's |
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| 25:28 | eventually happen at some point in This represents right many of these which |
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| 25:38 | lots of proteins. I mean lots our proteins. You gotta assemble |
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| 25:41 | You gotta put a genome in each of these. Right? So that's |
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| 25:48 | you have to copy each other. why you have to do translate and |
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| 25:53 | produce the viral proteins. So everything together. So that takes a lot |
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| 25:57 | energy. So the whole cell is as a result of that. |
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| 26:03 | So the consequences can be well, host was going to die, |
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| 26:07 | and eventually that will happen. But are some cases where the host doesn't |
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| 26:11 | even though it's infected, right? can be in this state here, |
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| 26:18 | it integrated into chrome zone. If virus does that Ronald genome does |
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| 26:24 | then the consequence of the host cell be minimal really. The hotel can |
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| 26:30 | on its merry way and just keep and functioning. No problem for a |
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| 26:35 | , eventually that will change. But that is a consequence for some |
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| 26:40 | Okay, even if they do do , right, they eventually have to |
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| 26:45 | back into this mode, Right? they ultimately are or they ultimately, |
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| 26:53 | just get rid of this, make host cell a replication complex a replication |
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| 27:02 | , basically make that post a replication for themselves at some point, it |
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| 27:08 | happen immediately almost immediately once they Or it could be it could be |
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| 27:12 | time down the road. And by , I mean, it could be |
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| 27:15 | , weeks or months for years. depends on the viral type, but |
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| 27:20 | that has to happen if they're going perpetuate themselves. Right. And so |
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| 27:25 | of that of course not just copying genome but transcribing translating gravel genes into |
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| 27:32 | . Right? That there will be symbol. Right. And so what |
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| 27:36 | of viral proteins? Well, certainly proteins to make the shell. |
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| 27:40 | And then there's gonna be other things we'll see. Um then a symbol |
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| 27:44 | law. Okay. And then uh exit the host and then go on |
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| 27:50 | infect more hosts. Okay, so couple of things. We're just for |
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| 27:56 | sake. I'm just showing one virus um there can be more than one |
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| 28:02 | affecting itself. Um what you see here? Okay. Mhm. In |
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| 28:11 | of comparing genomes, right. The of this virus that infected, Is |
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| 28:18 | going to be the same? That's all these progeny viruses, it would |
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| 28:24 | similar. But viruses do not have they were in the copying genome |
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| 28:30 | Okay. They're pretty sloppy about Okay. Because they don't have our |
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| 28:35 | we have all kinds of mechanisms to sure we don't make mistakes. If |
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| 28:40 | do make mistakes, we can fix . Right. And and we're very |
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| 28:44 | are our systems are very good at . Okay. Um viruses aren't because |
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| 28:49 | don't have that kind of apparatus. there will be mistakes made as they |
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| 28:54 | mistakes equate to mutations. Right. it could be that mutations form are |
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| 29:01 | too much to even make a viable . So it just goes away. |
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| 29:05 | . But the point here is that coming out right, these can slightly |
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| 29:11 | from each other. But I'm talking clones necessarily coming out. There will |
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| 29:16 | be variations among the proximity exiting. hope so. Okay. And |
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| 29:22 | viral types can also sometimes can infect . It's the same cell and that |
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| 29:28 | create more recombination of genome. Creating more variations. So that's the |
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| 29:35 | of the virus. Okay. Um I said, we will see variations |
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| 29:41 | different parts of the steps. But what you're seeing here, it's |
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| 29:45 | common all viral types and their Um Now one of the things where |
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| 29:51 | see complicated, more complicated steps maybe a process where you just visually look |
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| 29:58 | it is animal viruses versus bacterial Now, why would animal viruses be |
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| 30:04 | complicated? The bacterial are why would be are eukaryotic cells as simple as |
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| 30:15 | cryonics cells? No, that's the nature of why animal viruses will have |
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| 30:21 | more second more complex cycles. Because nuclear erotic souls. Their hosts are |
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| 30:27 | more complicated. So you have some some handle viruses that will go to |
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| 30:32 | nucleus and do things there are some don't um they'll synthesize proteins in the |
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| 30:38 | plastic particular and involved in gold et . So things that just because of |
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| 30:43 | of the eukaryotic host cell is more . So this lifestyle can be a |
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| 30:47 | more complex. So um so the . So again it's all about for |
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| 30:56 | the perspective of the virus and it's two. I want to produce |
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| 31:08 | It's gonna have to infect the Okay. Um And so there's two |
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| 31:14 | . There's the host range then there's I call maybe call it tissue |
|
| 31:21 | Okay. Or trumpism is the technical tissue specificity. You kind of think |
|
| 31:29 | those are kind of mean the same . So a broader host broad or |
|
| 31:36 | host range refers to how many different can a single virus infected? |
|
| 31:43 | Um rabies virus is the obvious Rabies virus can infect all different types |
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| 31:48 | mammals. Cast dog, human possums, squirrels, raccoons etcetera. |
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| 31:54 | many different host types. Okay. A flu virus, cold virus. |
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| 32:01 | much it's humans. Humans are the post they have. Okay. Um |
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| 32:08 | so measles and mumps. Another So a narrow host range. So |
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| 32:12 | means affecting only a small number of . One or one or a few |
|
| 32:18 | of course can be two or Okay. Um Now the tissue specificity |
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| 32:26 | tissue range if you will. Right that refers to in a single |
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| 32:31 | So for just looking at humans, we looking at a mass or just |
|
| 32:37 | a whatever spirit animal is. Right is. So just like you have |
|
| 32:42 | single host and we can take a example. Alright, rabies confirmed multiple |
|
| 32:48 | current host range but have a very tissue specificity. Very narrow trope is |
|
| 32:53 | okay rabies viruses only infect nerve That's it. Okay. Um E |
|
| 33:03 | and contract in fact multiple actually has narrow host range as well but has |
|
| 33:11 | broad um tissue specificity. Broad trope um I think it's like multiple cell |
|
| 33:17 | in a single host. That's one the Reasons it's such a deadly |
|
| 33:22 | You require Ebola. You have at about a 50% chance of surviving. |
|
| 33:28 | more upwards of towards 90% chance of . Okay 10% chance of living. |
|
| 33:35 | they can affect the effect cell types can um um make up your blood |
|
| 33:44 | and so if they affect those then blood vessels become leaky. Right? |
|
| 33:49 | dying from Ebola is dying from a where basically fluids are coming out of |
|
| 33:53 | . Right. Not a ah certainly horrific way to die but it's um |
|
| 34:01 | one of the main reasons why it such a high mortality rate number of |
|
| 34:05 | that can affect um Congress with HIV narrow super narrow one cell type, |
|
| 34:12 | ? Certain type of T cells T cells but in in destroying those types |
|
| 34:18 | t helper cells they just shatter the system at that the immune system which |
|
| 34:22 | the ability to produce antibodies and and things. So um even though it |
|
| 34:27 | have a doesn't not have a broad of cell types of effects that when |
|
| 34:32 | doesn't affect the type that's critical to 1's immune system. So um still |
|
| 34:38 | good. Now again let's just to that the target self host virus virus |
|
| 34:47 | cell relationship. Right. Sweeter. know, even even in this state |
|
| 34:51 | , just back up a second in state. They're sitting over here. |
|
| 34:56 | right. It could be a virus uh top of the desk here or |
|
| 35:02 | the door knob over there. Um they can remain viable in that |
|
| 35:07 | . Doesn't mean it's dead. Remember virus can be that occupy that |
|
| 35:13 | non living state. Right. And he can it can remain viable for |
|
| 35:18 | time. It depends on the viral . How typically viruses that are cause |
|
| 35:25 | like HIV papilloma virus, these generally as don't survive as well outside the |
|
| 35:34 | but certainly other types can't. Cold and other types can survive for quite |
|
| 35:39 | time outside of a host. But it all varies. Um the |
|
| 35:48 | Okay so again based structure as you is that capsule surrounding genome. Okay |
|
| 35:54 | we're gonna see some variations to Um one of the things to keep |
|
| 36:00 | mind is the small size of the means it can't contain a bunch of |
|
| 36:06 | . Okay so they're going to actually a small genome. Okay. And |
|
| 36:11 | it becomes important then to keep kind the structure is somewhat simple. |
|
| 36:18 | But then I mean you see and very common for to see this kind |
|
| 36:22 | geometric shape to a viral capsule. . We call these symmetrical types. |
|
| 36:29 | They can be filament tous or helical called or the 20 sided. |
|
| 36:38 | So you see in that type different . Right. So you have different |
|
| 36:43 | see these different color coded components. . Like so and you might think |
|
| 36:50 | , each one must be included for a gene. Alright well no there's |
|
| 36:56 | for this one, there's like three up the outer capsule three proteins. |
|
| 37:00 | it just combines those together to make capsule. Right? So it only |
|
| 37:05 | three genes for those three different capsule . Right. So it kind of |
|
| 37:09 | to maintain efficiency from that aspect because small. Okay and so the um |
|
| 37:19 | so the hepatitis a virus you see is just the protein coat caps, |
|
| 37:26 | surrounding genome. Now a variation of is an enveloped virus. Okay, |
|
| 37:31 | you see the catholic structure here. , in the middle with the black |
|
| 37:38 | , the hexagon with the genome But then you have the envelopes around |
|
| 37:43 | so the envelope has derived from the cell. So as it exits that |
|
| 37:49 | membrane wraps around it. Okay, enveloped viruses. Um I hate to |
|
| 37:55 | absolutes but I'm almost certain only I a viruses have envelopes but through |
|
| 38:02 | no because of the bacterial cell Right. So but certainly and not |
|
| 38:09 | animal viruses do animal viruses can have problem or not. So the ones |
|
| 38:14 | call that lack it are naked Right. So this is a naked |
|
| 38:18 | over here lacking an envelope. And so within the envelope can be |
|
| 38:27 | even though the envelope is host you will have viral proteins as a |
|
| 38:32 | of it. What we call envelope . Right. So these knobby things |
|
| 38:37 | see are are all viral encoded Okay. And we sometimes refer to |
|
| 38:42 | of these as spikes like glycoprotein spikes life for sugar to the protein combinations |
|
| 38:51 | and almost uh in most cases the themselves, they are this prominent like |
|
| 38:56 | see there are involved in attachment to holy recognized host attach and then begin |
|
| 39:02 | life cycle. Okay. Um so virus over here is also one that's |
|
| 39:09 | . Right? There's not an envelope it. Okay. And so the |
|
| 39:16 | viruses envelope, There's many animal viruses are enveloped. The flu virus Covid |
|
| 39:20 | enveloped virus. Um So again, are symmetric viruses. These are all |
|
| 39:29 | the casa. He'd roll type. . Just you see the kind of |
|
| 39:32 | pentagon shaped there. Alright. Um filaments, those viruses uh which are |
|
| 39:39 | symmetrical Ebola is one back of mosaic and you can also wrap the helical |
|
| 39:48 | or the filament this virus in an as you see here. Okay, |
|
| 39:53 | again you see the spikes. All now um a tale virus. This |
|
| 40:00 | a very common structure for a bacterial . They also call these subtext. |
|
| 40:05 | call these complex viruses because there are combination of different parts. You see |
|
| 40:09 | capture the capital structure here. All . But then we see a bunch |
|
| 40:14 | other stuff. Right? That's typically they refer to as a complex |
|
| 40:19 | Um The addition of these other parts kind of look weird in the |
|
| 40:23 | But that's really all a part of ability to attach to a cell to |
|
| 40:28 | fibers here, tail fibers. And part here called a shaft or sheath |
|
| 40:38 | actually compressible. It will actually compress top of the cell much like a |
|
| 40:43 | . And that genome then is shot which is sitting in the captured up |
|
| 40:49 | cut into the cell. And so bacterial viruses has mentioned they um it's |
|
| 40:55 | the genome that goes inside the Everything else stays outside. So when |
|
| 40:59 | see one of these particles okay without genome because it's just infected cell, |
|
| 41:06 | called it a ghost because it's just a protein shell. But there's no |
|
| 41:10 | genome in there because it's been inserted the host. Um Now asymmetrical |
|
| 41:19 | So you might look at that and , well that's not asymmetrical. It's |
|
| 41:22 | . Okay. And it's uh they're and so cold viruses like this. |
|
| 41:29 | covid virus is like this. The virus is like this um the it's |
|
| 41:38 | of a blobby oblong type shape. not a perfect sphere. Okay which |
|
| 41:42 | why it's a symmetrical can be kind um uh oblong kind of oval |
|
| 41:49 | Kind of you know amorphous blob in cases they kind of changes shape that |
|
| 41:55 | . Um And so the other thing this is a distinction is you don't |
|
| 42:01 | see the um these the genome itself be surrounded by curry with protein. |
|
| 42:11 | it's a nuclear nuclear proteins can just to the genome and coated. Okay |
|
| 42:19 | that's one way to protect it. but then it does have the |
|
| 42:25 | Okay it does have envelope protein sticking of it. So um the flu |
|
| 42:31 | , it's the don't worry about this we'll talk about it later. But |
|
| 42:36 | uh this part the H. And . Right here flu viruses having |
|
| 42:42 | And N. Numbers. Alright. one N. One H. Two |
|
| 42:45 | . One. What have you? refers to these two components of the |
|
| 42:50 | virus envelope proteins. The gluten is one that allows it to catch the |
|
| 42:57 | one allows us to use it the um the uh Tamiflu which you may |
|
| 43:04 | familiar with. Maybe you've taken it actually interferes with this component here so |
|
| 43:11 | can't exit the cell. Okay so so again so the there's so much |
|
| 43:21 | viruses. Um Even though the man around remember their parents just have a |
|
| 43:25 | about blobby form I think before we to questions any question about structure. |
|
| 43:33 | exactly about uh because it's not you you can't draw a line bisected and |
|
| 43:43 | halves because it kind of blobby It has it's not completely symmetrical the |
|
| 43:50 | itself or is it? Yes it's shape itself. Yeah. Uh Yeah |
|
| 44:03 | to the to the genome directly by to the genome. So it'll coat |
|
| 44:08 | whole length of the genome and so it's undergoing through life cycle it'll it'll |
|
| 44:15 | the genome. I believe that those will kind of come off that you |
|
| 44:21 | well it's copy then go back on bind to it. Not all not |
|
| 44:29 | viruses are like that but you will something like a flu virus. And |
|
| 44:34 | is the same way as those um I call proteins actually sometimes they're called |
|
| 44:40 | capsule proteins because there binding to the but but it's not a feature of |
|
| 44:49 | viral type but some have it that . Okay bring into question. Look |
|
| 44:56 | these questions. This is um this goes to you know particularly RNA viruses |
|
| 45:02 | we can apprehend heads around DNA viruses how the last several worked better because |
|
| 45:10 | like us they have a DNA Right So we're used to D. |
|
| 45:13 | . A RNA protein. Okay but viruses can have depending on the type |
|
| 45:21 | definitely be very different from that. and as we flip through RNA virus |
|
| 45:28 | cycles. It's me back up. the it's the RNA virus types that |
|
| 45:34 | to confuse people. Okay, so is a good this will show you |
|
| 45:42 | the first atomic beef. Sure. , mm hmm. Yeah. |
|
| 46:38 | Seconds. Okay. Here we Yes, it is only above. |
|
| 46:54 | . So as we'll see next time sure. Um, we can have |
|
| 47:03 | new viruses and so designation of plus minus. Alright. Plus minus |
|
| 47:12 | Okay. Or you can have You can have one that's called plus |
|
| 47:16 | . All right. And so the minus distinction. Okay, So here |
|
| 47:22 | let's just say this is um frankly you can be DNA DNA can |
|
| 47:31 | DNA RNA. Okay. Or it be RNA RNA. Mhm. And |
|
| 47:43 | all three combinations are possible. And I'm gonna bring this up because when |
|
| 47:48 | see what plus RNA virus, a or new virus. Okay. What |
|
| 47:52 | that mean? It really just goes to the clinic acid base pairing terminology |
|
| 48:01 | rules. Right? If you have and regardless forget create virus don't you |
|
| 48:07 | . But when you're talking about nucleic , whether it's DNA DNA DNA RNA |
|
| 48:11 | RNA, they each have that plus relationship to each other. Right? |
|
| 48:17 | if we have, let's just hey, you G C. |
|
| 48:22 | Well what is the complimentary form? ? From the U. A. |
|
| 48:30 | . G. Right? And this be the plus and that will be |
|
| 48:34 | mightiest. The point is they're not complementary complementary form to the A. |
|
| 48:41 | is not a UGC. It just work that way. It's not because |
|
| 48:46 | a virus it's just because that's the gas and rules. Okay. And |
|
| 48:51 | the plus strand those referred to as containing the coding information. Right? |
|
| 48:59 | can um it's RNA. The plus is the one that can be |
|
| 49:06 | Right? So that is one that be used for translation plus R. |
|
| 49:12 | . A. Okay. The minus . And the other thing is and |
|
| 49:18 | you're copying a plus strand let's say make it let's say these strands open |
|
| 49:24 | . Okay let me have a G. C. Okay. |
|
| 49:31 | C. G. Right so we a restaurant so that's opened up right |
|
| 49:37 | we're gonna copy it. Right. the copy for that going to be |
|
| 49:41 | minus or plus strand? Yes. It's gonna be -1 and this one |
|
| 49:45 | going to be a plus strand. . Just the way it works. |
|
| 49:52 | And so they have that relationship to other and so now the minus |
|
| 49:56 | Alright my strand. All right. be copied into A plus. Right |
|
| 50:03 | so that's actually what um that is the minus RNA virus. Right when |
|
| 50:10 | copies its genome that copies a Right and that's that's actually an |
|
| 50:15 | R. N. A. It be translated into proteins. Okay so |
|
| 50:19 | template that is can be directly translated A plus Arnie the template that can |
|
| 50:24 | copied into a translatable M. Is a minus party. Okay. |
|
| 50:31 | synthesis. Okay. That's the realm the retrovirus. Okay. Also an |
|
| 50:41 | virus. Okay. But it turns into a deal turns the okay so |
|
| 50:51 | different. All right. And so there's a reason it does that okay |
|
| 50:58 | retroviruses have the ability to what's the of making it into an art into |
|
| 51:04 | . D. N. A. do that? Yeah. Uh Not |
|
| 51:13 | because when it goes into um not because it will ah but I don't |
|
| 51:22 | the answer if I'd say it but get to the second anybody else. |
|
| 51:29 | . Now it kind of has to with the life cycle of the virus |
|
| 51:32 | a retrovirus. Let me remember what might recall the retrovirus what this mod |
|
| 51:39 | . Mhm. Um There are certain I mentioned we had a picture of |
|
| 51:44 | life cycle. Certain viruses can integrate a whole genome. So record viruses |
|
| 51:52 | what that's what they do. So they're an RNA virus they can't integrate |
|
| 51:56 | host chromosome unless they turn it into . Right There's the forms of |
|
| 52:00 | N. A. So you have integrate has to be set in the |
|
| 52:04 | material. So a retrovirus will will RNA. It's RNA genome into |
|
| 52:10 | N. A. And then they integrate into the host and they will |
|
| 52:13 | so retroviruses that do that can integrate the host chromosome and be there for |
|
| 52:19 | and years. Um Bless you. then um while in that state, |
|
| 52:27 | In the integrated state, they can express jeans. They can then initiate |
|
| 52:33 | lifecycle replication. Right? So we'll about that next time. But but |
|
| 52:39 | it's a unique type and it's not retrovirus there. Um There are |
|
| 52:43 | N. A viruses that do that well. Herpes virus uh if you |
|
| 52:49 | had like a type that gives you fever blister and it breaks out All |
|
| 52:54 | . That's actually the herpes virus that's into the chromosome to sell under stress |
|
| 53:00 | is when it, you know, out. It will come out of |
|
| 53:02 | come out of the chromosome begin And that's that reaction you get from |
|
| 53:08 | fever blister. The papilloma virus that cause cervical cancer. It's one of |
|
| 53:14 | pipes. So uh so there's like said, they're varies there's some viruses |
|
| 53:19 | that's what they do. They integrate the host chromosome. There's bacterial |
|
| 53:23 | What does that do that as Okay, so all different types of |
|
| 53:28 | . Okay. Um and so we really um this is one of the |
|
| 53:36 | things that people stumble over. It plus minus. And mm hmm. |
|
| 53:41 | does it do this? And not ? So one of the things you |
|
| 53:43 | to remember is is always what's the game for the virus is to make |
|
| 53:48 | of viral progeny. And then that's to exit the host and infect |
|
| 53:53 | Okay. So if step one is that process to make copy genomes, |
|
| 53:59 | ? Because we've got to put genomes all our assembly wired captives. |
|
| 54:04 | Well that means you have to copy or you have to copy that. |
|
| 54:10 | . What happened? Right. And you copy right, like I showed |
|
| 54:16 | , you copy a plus into a . If you're minus. Do you |
|
| 54:20 | if you copied into a plus? . That's why it happens. |
|
| 54:26 | And this will be this certainly is gonna be the last time I mentioned |
|
| 54:29 | . Right. But I figured that's kind of planted in your head now |
|
| 54:33 | we get there it won't be so , confusing. Hopefully. Okay, |
|
| 54:40 | , uh, let's look at I put this in just for yeah, |
|
| 54:45 | as a I know we're all sick coronavirus but you hear this, you |
|
| 54:52 | throw a rock at the picture if want. Um, uh, |
|
| 54:57 | so RNA virus. Okay. And , there's a table at the end |
|
| 55:03 | by no means memorize table that has the viral types and all the |
|
| 55:08 | Don't you memorize it? I put in there just to show really how |
|
| 55:15 | the viruses of group. There are many that us humans have interactions with |
|
| 55:21 | original are in a category. not just coronavirus, but the flu |
|
| 55:26 | cold virus, rabies virus, west virus which is endemic in this part |
|
| 55:31 | the States. Um lots of measles mumps, so many that are in |
|
| 55:36 | are in a category. Um This one of those plus. Right. |
|
| 55:41 | I mean it's genome can be can as a template to be for translation |
|
| 55:49 | . Um it has the spike proteins course. That's what the vaccine is |
|
| 55:54 | those um antibodies form will bind uh these spike proteins. Okay, of |
|
| 56:04 | , in doing so minimizes the chances greatly lessens the effect that they don't |
|
| 56:09 | host sex. Okay. Um it a genome you see here that is |
|
| 56:17 | . Right? So you see really lack of a of a one of |
|
| 56:25 | geometric caps. It's right. You really see that here in the |
|
| 56:30 | Right. It's because it's been replaced the capsule proteins binding to the |
|
| 56:36 | That's what you see here. Kind of that reddish copper ish |
|
| 56:41 | Those are those are called nuclear protein coding the genome. Right. |
|
| 56:46 | it kind of takes the place of , you know, for more general |
|
| 56:52 | of the capital we've seen. So proteins themselves, the capital proteins themselves |
|
| 56:56 | directly coat gene. Okay. Um so the so and again, don't |
|
| 57:06 | not gonna test you on this, just just if you don't know already |
|
| 57:10 | lineage of COVID are from 2000 to was the SARS a sudden acute respiratory |
|
| 57:19 | that actually was just confined, I it was Hong kong and didn't really |
|
| 57:23 | beyond That area to become a Um it subsided. And then just |
|
| 57:31 | years later it emerged that the Middle variety, again, it was pretty |
|
| 57:38 | just confined to that area. And third variation is third time's a |
|
| 57:44 | No intended. Uh that one obviously contained. Right, We can speculate |
|
| 57:49 | all the reasons for that. But that but they do share a |
|
| 57:56 | for sure in structure. They're all new viruses, coronaviruses, similarity and |
|
| 58:02 | oh, so much similarity, proteins things. So um so it's uh |
|
| 58:09 | and so one of the factors that to why it can cause this is |
|
| 58:15 | so for the delta variant, recall that had more severe symptoms. That's |
|
| 58:23 | the omicron we have now um as , in terms of the number of |
|
| 58:30 | uh if you're going to code it is the time to get it to |
|
| 58:33 | because it's not not near as severe what uh this form was. But |
|
| 58:40 | and part of it is the types cells, the solar cells in |
|
| 58:47 | that's a particular type of receptor found those cells and the covid virus actually |
|
| 58:52 | to that. So your LDL ourselves obviously in the if you don't recall |
|
| 58:57 | LBO lie right, a little small shapes, you know that we were |
|
| 59:05 | bronchial tubes all terminate, you know that's where the oxygen exchange occurs right |
|
| 59:09 | the line. And so certainly if cells are binding there, you're gonna |
|
| 59:16 | what's called an inflammatory response. your immune system will react. But |
|
| 59:21 | of the process is, you the fluid build up occurs in the |
|
| 59:26 | because of this effect and the inflammation um that you know, you |
|
| 59:33 | where are the symptoms like shortness of and uh it can lead to a |
|
| 59:38 | viral pneumonia. Okay. And obviously people died from this. And so |
|
| 59:46 | , the desert formulas of course, the delta variety, which of course |
|
| 59:51 | been now replaced by the omicron um doesn't have the severe effects like this |
|
| 59:57 | presume because the changes that occurred mutations these particular spike proteins such that maybe |
|
| 60:05 | doesn't bind as tightly or or maybe maybe doesn't reach down into the well |
|
| 60:11 | of our cells may be more upper track. Um so whatever the |
|
| 60:17 | it doesn't produce the same bad effects um anyway, okay, the |
|
| 60:27 | viral genomes. Okay, so um mentioned boxes small, nothing big genome |
|
| 60:35 | average size. It's probably in the base pair range. So here we |
|
| 60:42 | the zika virus which made notoriety maybe three or four years ago I |
|
| 60:50 | I think the first cases in South um affecting infants. Um, the |
|
| 60:58 | plus RNA virus it so some of kind of and I certainly don't, |
|
| 61:04 | don't have to memorize the specific viral that are synthesized but just to show |
|
| 61:10 | , okay, what are the types things the virus culture? Well, |
|
| 61:13 | proteins for sure. Okay. It have some other components that are involved |
|
| 61:19 | entry or exit of the cell, involved in the life cycle process. |
|
| 61:25 | very common for viral genes to be . They at different times. What |
|
| 61:31 | call early in late genes are very common to speak of viral genes |
|
| 61:37 | are turned on the beginning of the cycle and then turned off and then |
|
| 61:41 | that come later. And so we that initial parts of a viral infection |
|
| 61:45 | we'll get into the cell and the genome later parts of the infection are |
|
| 61:50 | and then exit. So there's going be different components needed at different times |
|
| 61:54 | that reason. Um The flu farmers bringing up again only for the fact |
|
| 62:01 | it's kind of unusual form of the . It's what we call segmented. |
|
| 62:07 | you see there's basically eight different segments . It's not one continuous chromosome. |
|
| 62:15 | so what that means is opportunities. for much more recombination occurring multiple viruses |
|
| 62:23 | a cell, Those segments can interact recombine with each other creating different |
|
| 62:29 | And so if you follow the lineage the flu virus, you're originated in |
|
| 62:36 | aquatic uh aquatic birds, ducks, , these kinds of things, wild |
|
| 62:42 | and then migrated into domestic birds, and so forth. Um And then |
|
| 62:49 | into swine. So in the re along the way it performs that eventually |
|
| 62:56 | humans. Okay. And you can at a flu virus genome and here |
|
| 63:03 | has been color coded. So you see the the lineage of yellow |
|
| 63:08 | avian or bird segments read I assume probably the swine segments, the green |
|
| 63:17 | the human form. So combinations and uh flu virus is constantly changing. |
|
| 63:23 | know, flu shot one year will work the next you constantly to get |
|
| 63:27 | flu shot. Um uh and so know, that's that's the nature of |
|
| 63:33 | flu virus, fortunately it doesn't have the level of mortality rate that the |
|
| 63:42 | the delta variant of Covid had. I think flu viruses like maybe .01% |
|
| 63:48 | . I think that delta variant was maybe 1% mortality doesn't seem like a |
|
| 63:53 | . But you know, when you talking about the population around the |
|
| 63:58 | it does become a lot. Um so hopefully we're gonna be in |
|
| 64:02 | state where with the omicron network it'll be around, it's like going |
|
| 64:12 | , but at least be manageable low like we can control and not cause |
|
| 64:18 | the stuff that has caused with So um any questions. Yeah. |
|
| 64:29 | . Actually I'm gonna do it again a 2nd 7 years. Hold on |
|
| 64:32 | I'm gonna end actually kind of with of that. And then it will |
|
| 64:35 | on next, you'll be sick of by the time this week is over |
|
| 64:39 | other. But yeah, I will into plus minus again shortly. So |
|
| 64:45 | talk just a bit about. So one viral roids and pry ons. |
|
| 64:53 | , um number one they're they're well forgot I had it written up here |
|
| 64:59 | . There are not viruses. You might say that virus like |
|
| 65:04 | because they require a host but they have the viral structure. I don't |
|
| 65:08 | a capsule. They don't have all other features. Okay, so a |
|
| 65:14 | basically is really only a concern. I can't say that because we depend |
|
| 65:21 | course many fruits and vegetables, that's of what the thyroids infected. So |
|
| 65:25 | were affected by that since we eat things. Okay. But in terms |
|
| 65:29 | directly affected, there's no virus the diseases or infections of humans as |
|
| 65:35 | as I know, it's strictly plants among plants, vegetables and groups seem |
|
| 65:43 | be the main one targets uh think version is the one that's been most |
|
| 65:49 | . But you know, in a aren't a it's basically infectious RNA with |
|
| 65:55 | , that's all it is. And uh we all know Arnie's not |
|
| 66:01 | stranded like DNA but RNA can fold . Right, so it's all complementary |
|
| 66:06 | parents. And so it can fold and that secondary structure we call it |
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| 66:11 | important to its viability. Its That's right. RDS can have catalytic |
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| 66:18 | . Okay, These are relatively You can see they're just under under |
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| 66:25 | nucleotides long. But remember that RNA RNA can be have enzyme activity. |
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| 66:32 | the RNA that makes up the small of the Viber zone is the one |
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| 66:36 | forms the peptide bond. Right? they can have that. But the |
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| 66:40 | implants is typically gene expression. I the virus itself can interact with proteins |
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| 66:47 | it can interfere with the expression of . Okay, that's basically what they |
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| 66:53 | . Okay, um now the Okay, so whereas viral roids are |
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| 67:00 | RNA molecules and that's it. Nothing more to them. And they do |
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| 67:04 | to host our memories to replicate But the Priam's now are just proteins |
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| 67:11 | themselves. Right. So prions um infectious proteins. There's no gas id |
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| 67:18 | nuclear gastric component. There's you it's just a protein. It folded |
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| 67:23 | . Right? And that structure is for its function. And so these |
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| 67:28 | um I think first discovered in sheep is a disease and sheep, it's |
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| 67:37 | neurological condition. It's the name, the legacy clinical name spongiform encephalopathy encephalopathy |
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| 67:48 | of describes kind of what it really. Um So in a affected |
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| 67:56 | it will pry on protein. So is a normal form that's present in |
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| 68:01 | and in other animals. Okay, has a function. We don't really |
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| 68:05 | what the function is. So the prion protein, as weird as it |
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| 68:11 | . I've seen that there may be role in copper copper metabolism. It |
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| 68:16 | been confirmed. But I see that lot in terms of potential functions of |
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| 68:21 | normal form it's found um a lot neurons. Okay. I think the |
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| 68:28 | membranes I believe. And so um the normal form is of course benign |
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| 68:36 | cause disease. That's when it becomes admiral form. You see there on |
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| 68:40 | right, that form is the one informed they form aggregates together. They |
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| 68:45 | of clump together. Okay. And disease which is called Creutzfeldt Jacob |
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| 68:52 | So apparently in each animal type it its own name. Okay. It's |
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| 68:57 | being goats. Um Creutzfeldt jakob in , I mean scrapie in sheep, |
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| 69:03 | don't even know that but that's that's because it um And so the the |
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| 69:11 | of these animal forms leads to uh generation death of the neuron eventually it's |
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| 69:19 | very slow progressing disease. Right? not doesn't happen overnight accumulation of damage |
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| 69:26 | neurons myth. And then when a uh dies. Okay, degenerates, |
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| 69:33 | left with basically uh an open spot the brain tissue. Okay. And |
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| 69:38 | these but they are sometimes called Um But basically the brain tissue becomes |
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| 69:45 | of holes where the neurons used to and that gives the the that tissue |
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| 69:51 | spongy consistency, hence the name So you get you get that kind |
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| 69:56 | form to it. Of course you imagine the effects of that uh severe |
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| 70:01 | impairment and motor lack of motor skills whatnot. Right? So but again |
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| 70:06 | slow progressing disease. Um and so quote air quotes replication, it's really |
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| 70:15 | binding. So so a misfolded form to a normal form and that in |
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| 70:23 | creates the abnormal form. So it like a chain reaction occurring again gradually |
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| 70:28 | time, where then it becomes more more full of these prion proteins. |
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| 70:35 | . Uh Apparently I guess because the it folds up, it can be |
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| 70:40 | resistant to chemical treatments. Uh Physical . High heat. Okay. The |
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| 70:47 | way you catch this is eating the of an infected animal. But even |
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| 70:53 | the number of cases of mad cow in the United States is like infinity |
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| 70:58 | , right? You're not that's something not gonna die of. Just put |
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| 71:01 | that way. Um But you in in the rare case you do |
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| 71:08 | eat meat of a suspected animal, basically beat the heck out of |
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| 71:13 | Okay, no, rare steak would super well done. Okay. But |
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| 71:18 | then I probably wouldn't want to eat anyway, but all because of the |
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| 71:21 | of the protein to these conditions. And so this little graphic here just |
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| 71:27 | kind of there's kind of shows the forming where the neurons used to |
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| 71:32 | Um And then uh kind of a or just showing red shows the accumulation |
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| 71:40 | the abnormal forms coming together. Um in the neuron will will degenerate, |
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| 71:47 | function. Yes, this aggregation Okay. Um there's no other kind |
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| 71:54 | prion human prion disease I'm aware of than this. Okay. There there |
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| 71:59 | is some evidence that aside from acquiring , you're eating infected meat. Is |
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| 72:06 | there may be a genetic component, I'm not sure how well established that |
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| 72:12 | . Then maybe you can share it then the leo for this misfolded |
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| 72:17 | There is some evidence to suggest Um Anyway, so that's so prions |
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| 72:24 | viruses, infectious RNA is infectious Okay. And no really no other |
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| 72:30 | components to either of those things. , um let's look at this |
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| 72:36 | Okay, what do you think about ? Any questions about thyroid problems? |
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| 72:48 | , he said it just takes a like I said, it's still progressing |
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| 72:53 | humans. It takes a while to if I assume it probably can mimic |
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| 72:59 | dementia. I would think that those of things would creep in as your |
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| 73:03 | slowly degraded. Um But yeah, it's it's slow progressing. So those |
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| 73:08 | kind of the kind of things. see. Maybe motor function begins to |
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| 73:12 | after the bad things. Yeah, not aware that they're there is. |
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| 73:20 | don't think there is any kind of for that, I think to be |
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| 73:24 | , I'm not really sure how far are actually working on that because it's |
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| 73:28 | rare to get it. But I'm aware that there is any kind of |
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| 73:32 | for it. Okay. Timer Oops. Sorry, mm hmm. |
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| 74:10 | . Any strangling and jump in hurry . Okay. Which could not be |
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| 74:17 | as the cartridge. You're right. gonna be can't ferment, right? |
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| 74:21 | not gonna be like an e coli it's gonna ferment the sugar or |
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| 74:24 | Okay. But certainly the other the are possible things you can use to |
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| 74:30 | viruses. Okay. Kind of the is um the Baltimore classification which basically |
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| 74:40 | what's what's the genome type and what's route to get to the M. |
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| 74:47 | form where you can then translate into proteins? Okay, D. |
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| 74:52 | A viruses that's fairly easy for us wrap our heads around because that's how |
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| 74:57 | do DNA RNA protein. Okay. now the RNA viruses mentioned earlier can |
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| 75:04 | a little trickier than the one thing have. Right, this is absolutely |
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| 75:08 | viral enzyme. Is this an independent april embrace? Okay. We |
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| 75:15 | What kind of memories do we We have a D. N. |
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| 75:20 | dependent much different. We only produce S molecules from DNA templates. |
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| 75:29 | That's not what an RNA virus It copies its art and you know |
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| 75:34 | to make another RNA is a copy that. Right. And that's what |
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| 75:38 | RNA dependent RNA polymerase does. So we would you carry those? |
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| 75:43 | don't have that enzyme. It's a enzyme. Okay. And so um |
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| 75:49 | the plus on a virus. The that directly is a template. |
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| 75:55 | ? It's it is an M. . You can make proteins from that |
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| 75:59 | proteins from that. Uh In the course the double strand has both |
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| 76:04 | Plus and a minus. So you directly uh copy the the translate to |
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| 76:09 | stream. The plus single strand of . Um is one that ah can |
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| 76:18 | copied into a minus and then copied a plus. Okay, he could |
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| 76:25 | form right here could serve right directly a as a template. Okay. |
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| 76:33 | protein senses but it becomes a numbers . Right? Remember they always from |
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| 76:38 | enemy. They make lots of You need lots of protein. So |
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| 76:42 | one genome coming in isn't gonna really enough to make a lot of protein |
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| 76:46 | quickly. So let's let's make more of that N. R. |
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| 76:51 | The only way to do that is go through this intermediate. Okay, |
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| 76:56 | , it's not because it's a It's because it's a nucleic acid base |
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| 77:00 | rules. That's all it is. . So if you wanna make lots |
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| 77:04 | copies of this then we have to lots of copies of the miners. |
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| 77:10 | to make probably the plus room. , so the plus minus again is |
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| 77:17 | um the relationship between the two nuclear acids, right? It could be |
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| 77:21 | . N. A. D. . A. On your right. |
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| 77:25 | just one of those the plus train carrying that coding information. Okay. |
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| 77:30 | other one is the anti sense we it. Okay. And you can |
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| 77:34 | the minus anti sense and copied into plus sense of strength. It's what |
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| 77:39 | do when we're when we're carrying out translation, right? We're taking a |
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| 77:47 | minus DNA strand and popping into a RNA strand. And that's the |
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| 77:52 | R. A. That goes to right. So that's what we do |
|
| 77:56 | ? The virus is not doing anything . It's just following those base pairing |
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| 78:01 | . Okay. So as mentioned right? The the the minus RNA |
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| 78:08 | be copied into A plus and then retrovirus into D. N. |
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| 78:15 | Questions. I'm gonna go over it . And you have to start next |
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| 78:18 | . But you can hold on I go to lab those things that many |
|
| 78:23 | you do. Um But for some you do but so I don't want |
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| 78:29 | hold you up. But we will we'll begin next lecture with this as |
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| 78:33 | . So plus minus think about Okay. Yeah mm |
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