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00:00 Wait, why is this? Goddamn ? Come on. Alright. Alright

00:29 . Uh Let's get started here. Alright, so we are back on

00:41 . So routine, right? Weekly blackboard quiz. And then a smart

00:48 assignment do. So just I sent an email like about 15 minutes ago

00:54 I came over here. So it's that. So it's got this on

00:58 . So just the specifics. So quiz opens tomorrow Basically what we talked

01:04 Tuesday viruses continuing today, we'll finish and start chapter 13. Okay.

01:12 Alright. So is there something Okay, I can't think of

01:19 Um All right. The I think forgetting something but if it comes to

01:28 , I'll stop and think of it I think of it. Anyway.

01:34 So just a little bit of a uh review brief review where we were

01:40 last time. So again. So going through um went viral structure right

01:48 week um defining a virus. The of the virus uh contrast with the

01:54 void and prion. Remember those two are not viruses, they're they're infectious

02:00 they're kind of their own unique things RNA infectious protein. Right? So

02:05 is pretty much what we're focused So um we looked at the structure

02:11 week um the basic structure right? caps it surrounding a genome of some

02:18 . But then of course we went all the variations of that structure and

02:23 last time began into viral life Right? So we started with bacterial

02:29 cycle? Bacterial virus life cycle. bacteria fage. Right. And um

02:37 so this viral replication uh like uh a virus, right? The estrogenic

02:46 ? Okay. Um the equivalent to was in a animal virus. Wright

02:53 the pro what we call a pro state. We'll get to that.

02:58 . Um very analogous to the So ginny. It's just it's just

03:03 viral chromosome inserting into the host Okay. And so am a virus

03:07 certainly do that as well. The papilloma virus we talked about

03:11 can insert itself and you know, that can be causes of cancer,

03:15 cancer, women. And so um HIV virus can do this. Herpes

03:23 can do this. And so um backing up here a second. So

03:28 then went into um animal viruses and course is gonna be a little complicated

03:34 animal viruses, in fact of course cells, right? Eukaryotic cells are

03:39 complicated so different organelles can get involved the replication process. Right? The

03:44 . R. And the plastic particular will be used for protein synthesis of

03:51 proteins. Um the nucleus can be landing spot for D. N.

03:59 viruses typically. Although there can be . RNA viruses tend to do their

04:04 outside the nucleus but again for this most things in biology where most will

04:11 a pattern. They're always gonna be outliers. Okay so um and so

04:18 with animal viruses and they're beginning with into the host. Right? The

04:23 process, the encoding is simply just the viral particle allowing its genome to

04:32 released into the cytoplasm because and that's initiates the replication process. Okay.

04:38 unless that viral genome integrates. So that's that's another scenario. But

04:44 it has to get in there of the recognition of the host cell then

04:51 in whether its diffusion um through endo process uh that genome is released inside

05:00 cell whether in the nucleus or outside nucleus. Okay. And so um

05:06 so we looked at last at this . N. A virus um

05:11 N. A virus life cycle. . And this is the papilloma virus

05:16 very typical for D. N. virus that goes to the nucleus.

05:21 encoding process occurring in the nucleus. , so here's the genome using host

05:31 um then there's gonna be events occurring the nucleus and inside so remember that

05:38 synthesis can only occur outside the That's when the components are at.

05:43 . And then viral proteins within commuting and that's where assembly will occur is

05:49 for a D. N. D. N. A virus.

05:52 , so the genome being copied in nucleus then assembling everything together intact viral

05:58 exit. Okay. And so the viruses okay, will acquire their envelope

06:09 they exit the cell. Okay. is not an enveloped virus um the

06:18 any case the you know whether if are viable virus, that's where you

06:22 acquire it. So as it comes it would wrap around the virus and

06:26 have its envelope and associated proteins. . And so not shown here because

06:33 the Golgi er and Golgi can be in the process um to produce the

06:39 viral particle. Okay. So the we're gonna focus on for the rest

06:46 the time as we finish up it's gonna be the RNA viruses.

06:50 . That's likely going to be the that causes some complications. Okay.

06:56 before we do that, is there kind of general questions to this point

07:01 anything? Whether it's vital structure would ? Yeah. Um I want to

07:12 yes they do. The ones that . Um the ones that vary well

07:25 mean let's say most will do that you can have variations of where the

07:31 doesn't go to the nucleus actually. um yeah they have their own host

07:38 polymerase. And so I think monkeypox like that. Um It could be

07:44 think I think that's an example of . But there are again outliers

07:47 So there's even the flu virus which an RNA virus actually does use the

07:52 as part of this process. And these are outliers So general thumb is

07:59 know d N a prior to go nucleus and do their thing are just

08:03 outside completely of the nucleus. But always a few that don't follow those

08:08 . Any other questions. Alright so let's look at this question. Okay

08:20 this is a segue into the army . All right. So um an

08:26 virus possessing a single plus we call strand RNA as its genome.

08:35 Plus RNA virus would first have to this into a minus what we call

08:42 sense RNA. Then translate from this anti sense into viral proteins. Is

08:50 what a plus strand would do? , true or false. Mhm.

09:39 posit briefly. Okay, here we counting down from three 21.

09:55 Okay. We need to clear that . Okay. All right. So

10:03 yeah with these are the viral life . The thing to remember is what

10:08 represents. Right? That's the form you can translate into proteins. In

10:14 words, ribosomes can plop down on and synthesize protein. Okay, it's

10:20 that form that allows that that's the to make proteins so it has to

10:27 there to be able to do Okay, so uh the question is

10:33 here is um so what happens is that of course is copied from the

10:41 . D. R. P. the RNA dependent RNA polymerase.

10:45 so whenever you copy this the whether it's no matter what kind of

10:51 peak after you're talking about if it's . N. A. Um you

10:58 plus and minus D. N. strands. Right. It can be

11:01 D. N. A. You that you form a minus D.

11:04 . A. Okay you can even a, you can copy into RNA

11:08 we know. Alright that would be minus RNA. Okay copy of minus

11:15 . N. A. Could be could be A plus D.

11:16 A. Could be a minus plus . Right? So the rules I'm

11:23 torturing with torturing you with these plus minus things because we're talking about RNA

11:28 . Plus the minus is simply a of how how nucleic acids work.

11:34 ? Because again um just that's a RNA. So au G.

11:43 Right? So if we copy that not copying it into a UGc.

11:50 ? So this were plus. That we'll be copying into a plus

11:54 Right? And that's not the rules how nucleotide bases match up.

11:59 So we make the complementary strand which be um not you. Thank

12:08 Bye. Alright uh you A. . G. Okay let me divide

12:17 here. So it'd be that. so that we're plus and this would

12:20 the minus strand. Right? So just simply the complementary base pairing

12:24 Right? That's that's what it's all . Whether your D. N.

12:26 . R. N. A. hybrid doesn't matter. You follow the

12:31 rules. Okay so um let me this off the board so just remember

12:40 . Okay um Alright so what we're then we can then only translate.

12:51 let me get this out the Uh Let's do this options. There

12:57 go. Okay, So um So minus is not translatable. You have

13:03 translate using the plus strand. So this would be the life cycle

13:09 plus RNA virus. Okay. And I understand is so as written,

13:17 question is false. Okay, So strand with first transcribing the minus.

13:24 correct. Right? But then that's first part of the question going from

13:28 to here. Okay. But the part is not Right. Right,

13:33 would be copying to another plus. , so again, I realized you're

13:39 Okay, what the heck? we're already here. It's a virus

13:43 has a plus genome. Why do have to go through all this

13:47 Why do that? That's insane. . Well, as I said at

13:51 beginning, way back a couple of ago in our last lecture, you

13:57 think of the perspective of the right? It's infecting itself the

14:01 Ultimately make lots of viral particles. ? And if you're gonna make lots

14:06 these This is my generic virus Okay, so that's obviously going to

14:14 protein. Alright, captured. Uh then we're gonna put a genome here's

14:22 genome, you know, genome Okay. Uh We got got to

14:30 it inside here. All right. , if we're gonna obviously a virus

14:35 gonna make more than one viral Right? We're gonna make tons of

14:41 things dang it tons of these. ? So, that obviously represents lots

14:51 viral protein synthesis, right? Protein proteins, proteins, proteins,

14:59 We have to put genomes and all things, genome genome genome genome

15:04 right? It makes 100 of these . That's a lot of genomes you

15:07 have. Right? So, that's you get So, it's infecting one

15:13 infecting with its plus genome. That's gonna be enough. Okay, make

15:18 of this. Right. And the to do it is to do with

15:20 route. And we have to do this route because of the copy of

15:23 into a minus minus into a That's just that's just base pairing

15:27 right? That's something diabolical diabolical plot , you know, torture you.

15:34 the way it works. And um so that's why it does it

15:39 ultimately at this point here, this lots of them, Right? Lots

15:46 lots of this. Lots of Right in this process. Right

15:55 And then it goes into a assemble viral particle. Right? So,

16:02 need lots of this. But of course, you need lots of

16:06 . Right? So, these templates lots of templates to make service genomes

16:10 stuff into the thing. But then lots of templates where rival zones can

16:15 on and make viral proteins. So this can all happen very

16:18 You have you have more stuff to with. You can make more in

16:22 more quickly. Right? So more these are around that means more opportunities

16:28 rival zones to do their thing and lots of viral proteins. So it

16:31 comes together to make of course these particles. Okay, so that's why

16:38 yes, even though it's a plus virus and its template directly serves as

16:43 template for make proteins, it's about of stuff and it's about making viral

16:49 get copies of the genome as And of course these guys this is

16:52 plus RNA virus. Then these all to be plus us are in a

16:59 . Right? Because that's what the is. That's the type it

17:03 So um that's why we have to this. Okay, and we're gonna

17:09 the same thing. We're looking at minus RNA virus the same process.

17:14 ? Um So, I'm basically gonna this again. So because that's the

17:20 slide. Alright, um so let's you that. Okay, so let's

17:27 here. Okay. Already said all . All right. So just to

17:32 of the templates for RNA viruses. . So if you're on the virus

17:36 can be a plus. Right, a template for translation. You can

17:40 a minus. All. Right. a template to make a A plus

17:46 . N. A. So, so this is not a template to

17:50 proteins. There's a template to make M. RNA which can make the

17:55 . Right? And then of course retrovirus is its own thing. It's

17:58 template for DNA synthesis. Right? it's RNA. DNA. RNA proteins

18:03 how retrovirus operates. Okay, as here. Okay so uh and it

18:11 the DNA intermediate because its mode of cycle mode is typically to integrate into

18:18 host chromosome. Okay so that's why first stop for its genome is copied

18:24 DNA. Because that's typically what it . It does this Okay then down

18:29 road at some point it'll go from form DNA back to RNA and then

18:35 to protein. Okay, we'll talk that at the end. Okay.

18:40 . So let's look at um look this. Right here is our

18:47 So we just we just went over in the question. Okay that was

18:52 example there. So uh I just some examples. So remember all the

18:57 viruses groups. Right. Have a of ones that contain human diseases of

19:02 types that we're all familiar with. So you're plus our name. So

19:08 drew it this way to really emphasize what's coming in and infecting the cell

19:14 it's gonna have to do this. ? Make lots of viral particles.

19:17 . Each one containing genomes. That's we have to make copies of

19:22 Okay and so we start with our independent memories. Okay so again this

19:31 not it couldn't get this from a cell because eukaryotic cells don't contain these

19:37 of RNA polymerase. We have what called D. D. R.

19:42 . P. DNA dependent RNA polymerase right? That's not what this

19:46 Right. Our preliminaries is our memories specific for D. N.

19:49 Okay, so they wouldn't be able get this from us. Okay,

19:53 they have it that's a viral particularly enzyme. And so the process is

19:58 make a copy and make the minus . Right? Plus the minus and

20:02 two plus. Okay. Uh and these are pretty much there's nothing it

20:07 really do with these. Right? because it's surrounded, that's because it's

20:12 way nucleic acids operate when you copy . This is just gonna be

20:16 Okay. But the point is, though they may not be as written

20:21 as the form of the rin completely , they are useful as templates because

20:26 we have lots of these, that can be made into lots of

20:32 . So that's the key for this or gal. Okay. Is this

20:37 realized I say this guy a I need to not say that and

20:41 be all inclusive. Okay, so that's sexist on my part. Um

20:49 way that you can refer to a as a he or she anyway,

20:52 it all right. Anyway. So so the point is, right,

20:58 though this is this is how you to do it. And so you

21:02 lots of these now. And so gonna serve us both templates to make

21:07 which it will need to do a of that and then can package into

21:10 particles as well. Okay. And assemble and in fact get out of

21:16 cell and infect more cells. Um so before you ask questions,

21:25 gonna stop for questions in a Let's go through this one minus RNA

21:30 . Okay, so um again, illustrated this way to show you here's

21:36 coming in here's what's gonna have to out for this for these viral

21:40 Right? So we need lots of RNA templates. Okay, so

21:46 viral enzyme makes lots of plus Okay. And for this particular virus

21:54 means it can make its proteins. it's not minus RNA virus but it

22:00 it into the plus minus two plus these are all templates for making

22:05 So here's how it's gonna make its . Okay, but we have to

22:10 make another round of replication of these again it's a minus RNA virus,

22:15 a plus. And so we do again to make our genomes which then

22:21 be stuffed in to our particles. so this is so both the minus

22:27 stranded minus and plus RNA is have go through these consecutive cycles of replication

22:33 because a that's how nucleic acids are plus minus or minus two plus

22:40 Um they they have the plus has the uh the platform is what you

22:46 proteins out. Okay. And for plus RNA virus it's also doubles as

22:51 genome. It's gonna use the stuff the viral particles for the minus

22:56 The plus form is critical because that's form that of course is translating the

23:00 . Okay. But it's not the that it can stuff into a assembling

23:06 particle because it's not a minus RNA , it has to go back and

23:10 these to make the minus RNA genomes that gets stuffed into that.

23:15 Um Not yet. Well yet. so this is an example of plus

23:23 virus. Okay so you see um of the host and uncoated process.

23:31 , releases the genome. Here's the proliferates. Okay. Um and then

23:39 I can use you know the host E. R. For um pretty

23:46 . Um Then uh capsule assembly of . It proteins insert genomes,

23:53 And it takes its envelope virus. will have that wrapped around it.

23:58 a naked virus, it won't have envelope. All depends on the

24:02 Okay. But um any questions about cycle or this cycle? Any questions

24:14 I really just think, you as I began both of these slides

24:18 this. Right. It's you have think in terms of that beginning and

24:25 . Alright. And how it gets and why it has to go through

24:32 ? It seems like a redundant but it isn't isn't. I mean

24:36 two rounds of copying, but each is creating a form essential for

24:40 Right. For this one, it's the templates to make proteins and then

24:46 producing the genomes to put into the particles. Okay. Um Yeah.

24:54 questions. All right. All So, here's a question. I

24:59 should be a slam dunk. I hope. Okay. Is which

25:06 of these? What does one of not need? An already dependent on

25:10 plane race. Okay, so, as you're mulling this one over?

25:33 So what about four slides? five comes the dreaded metabolism. Okay,

25:45 yeah, yikes. It's actually probably favorite thing to teach in this

25:49 Is that um All right. Oops. Be anonymous. Oops.

26:02 button. There we go. That's one. All right. Okay.

26:12 think I think everybody pretty much knows one driven by the everybody's answered already

26:19 down five. Will it be I predict. No. Okay.

26:28 , is not needed by retrovirus. , so retroviruses not copies of RNA

26:34 DNA. Okay, so, uh primaries it does use can just be

26:40 host preliminary because it copies its DNA RNA. So there's no requirement for

26:47 dependent RNA polymerase for it. so, um retrovirus is the one

26:53 does not need it. Okay. Alright, so retrovirus. So here's

26:59 retrovirus looks like it's life cycle. , examples. of course. I'm

27:03 you're aware HIV also the feline leukemia which is actually a model to study

27:10 . Um And so again, beginning in the end game. Alright,

27:15 it's gonna be a plus RNA Of course, we will have to

27:19 that genome inserted into viral particles. , so um so the reverse

27:26 So that's a uniquely viral enzyme for group. Okay, um copies and

27:33 here again, you can see, , copying rules from nucleic acids.

27:37 ? So RNA to DNA. Same . Right? Plus or a minus

27:41 . N. A. Okay, uh single strand. So then the

27:47 DNA plum race to make a double molecule and it has to be double

27:53 . Why isn't this why Why why this enough? Why can't just be

28:02 ? Ah correct. But the other to make a double strand is because

28:10 going to integrate into the host Okay, so um uh that's why

28:19 got to be double stranded. Um also like the minus strand is not

28:26 that you can yeah, it's because have to integrate into the host

28:32 So the uh so if it's in replication mode. Okay, so this

28:38 be a state where this is part chromosome, Right? This could be

28:46 of the host. This could be host chromosome and it's integrated into

28:51 Okay, his own. Okay. chromosome and there's the viral DNA stuck

29:03 the middle of it. All So um so that could be so

29:08 could be in that state for a but it could be in that

29:13 Stay in that state. And then synthesis of of transcripts. Okay.

29:19 RNA and translate the viral proteins assemble and then exit. Right. So

29:27 retrovirus is one of those that can be in multiple states. If you

29:34 it can be um sitting in a doing nothing okay at all. You

29:42 just sit in a chromosome and then direct synthesis of viral particles. Um

29:49 could just pop out pop out of genome completely. And just now then

29:54 up viral production. So all three those scenarios are possible. Okay.

30:00 and so we can see the actual here of a HIV infection. So

30:07 is very specific in terms of cell infects. Um So very narrow trope

30:13 um okay. Um and also narrow range. Right? So we'll talk

30:19 these cell types later in the We talk about immune system but t

30:26 cells and it's a specific type of helper cell. Right? There's different

30:30 of these. And so um to ourselves as we learn well we will

30:36 are instrumental in really controlling the entire system response, adaptive immune system

30:45 That's the part of the immune system produces antibodies and has other effects.

30:49 , so um can help ourselves of type of effect are very important in

30:54 . So you can imagine if you're off these things eventually it really devastates

31:00 advantage being system um in any So here is a retrovirus uh

31:08 recognizing the particular this particular proteins that that are only found on t.

31:13 cells uh gets entry on coding So here's our reverse transcriptase that it

31:19 with it um copying eventually into double DNA. Using the transcript place plus

31:27 DNA primary and then that will integrate the host chromosome. Okay and so

31:32 uh those that are uh H. . V. Positive. Okay.

31:38 remember when we talk about animal viruses they integrate into the chromosome we call

31:43 pro viruses. Right contrast with although in bacterial viruses we call the pro

31:50 . Right? With misogyny here, called pro virus with animal viruses.

31:54 . But both are similar in terms its it's the viral genome integrating into

31:58 host chromosome. So what we call state, that's where it's kind of

32:04 sitting in the um chromosome doing Okay. Just sitting there and it's

32:11 kind of along for the ride. as the host cell is doing whatever

32:16 doing multiplying or whatever the virus is sitting there. Okay. Um and

32:23 you don't know in fact it's so who's HIV positive would not test positive

32:33 in that viral state. So it's virus is in a latent state where

32:37 not doing anything just hanging out in chromosome not even producing any viral

32:42 So a person in that condition has symptoms of disease um would not test

32:49 HIV positive uh because HIV test is on is an antigen test antibodies a

32:58 for the presence of management. And viral particles aren't being produced at

33:02 There's nothing to detect. So then can't enter a state where it hangs

33:09 , still stays in the chrome zone then slowly direct synthesis of of viral

33:15 . Okay, so here's a budding . So these are enveloped viruses,

33:20 proteins that go into the envelope are not shown here, but they're probably

33:27 of the golgi. But then we to the surface and they have these

33:32 proteins sitting on the surface. And the viruses bud bud. Remember the

33:35 process? They'll have that wrapped around as they exit. Okay. Um

33:42 so we could do that at a rate. Right? A few viruses

33:45 a time and the cell remains Okay. Um but then, you

33:51 over time you'll build up enough viruses would be detectable and then you'll be

33:58 HIV positive when enough of these are that are floating around your body and

34:03 it can be detected. And so that that can be from time to

34:07 . This virus integrates into the chromosome you see detectable levels of virus could

34:13 months or years before that happens. . Of course in that time uh

34:22 cell that's in can multiply. And more and more cells t t

34:27 cells will be present containing each containing of the viral genome. So you

34:32 it's all of the virus technically by is a multiplying the whole cell in

34:39 in can be replicating and it can of perpetuate itself that way.

34:43 And then now you can have all infected cells begin to produce virus and

34:49 that's what can cause the body to overwhelmed by it. All right,

34:54 the immune system. Uh because I'm as you know people that have HIV

35:01 although nowadays you don't it's it's not it was back in the eighties um

35:07 it was just you know the death typically um now you know people live

35:12 lives full pretty much a normal You know with with this because it

35:16 be controlled with a variety of different drugs and whatnot. Although of course

35:22 not the case everywhere on earth because is still epidemic and parts of the

35:28 africa and elsewhere. Uh and that's whole other reason cultural and otherwise that

35:35 don't have access to the drugs. if you have access to drugs and

35:40 can be have a pretty normal Okay. But that's that's a whole

35:46 political medical issue otherwise. Right. like many things are these days.

35:52 So any questions? Okay so um then you have to go rage against

36:02 pharma. Right? It's a I I do sometimes but for different reasons

36:08 . Alright. Um Okay so animal plant post defenses. So we talked

36:15 this in the context of bacterial host of course. And talking about pages

36:21 of course. You know those that affected by viruses have ways to

36:26 Okay. Uh as with you a common defense is simply just acquiring

36:33 in those via mutation through the the on the surface by which the virus

36:41 entry. Right? So think of as a lock and key.

36:45 If you change the lock right then virus the virus key can't get

36:50 Right? So you change it and can't bind or binds very weakly and

36:54 infect very well. So that's a common way to counteract or minimize viral

37:00 . RNA interference is another one. talk about that later in the

37:05 But um that's a widespread mechanism. express RNA S. That can um

37:13 two viral genomes and interfere with expression viral genes. Another one we'll talk

37:20 later. So immune immune system you produce antibodies of course the viruses that

37:27 have various effects. We'll talk about later. Um innate immunity. So

37:33 real briefly. So I'm sure you this is your innate immune system compliance

37:38 what you're born with physical barriers you against infection. The various types of

37:45 barriers you have against infection um including of interferon. Okay I'm not gonna

37:52 into details now because we're going to about it later anyway. But basically

37:56 they do interference are um can are me to show you this. So

38:04 are triggered by a viral infection. here's a cell could be one of

38:09 cells that's infected with the virus and infection itself is what induces production of

38:15 . Okay so the virus infected cell the one that gets triggered to do

38:21 and so interference is secreted by the and so neighboring cells it can diffuse

38:27 and neighboring cells if they have the for it will bind interference and that

38:33 trigger the production of antiviral proteins. the infected cell will likely be sacrificed

38:40 die as well to the infection. it gives off the protective interferon to

38:46 these other cells that can produce antiviral to counteract infection. So that's that's

38:51 innate immune immune defense you have. to counteract the viral infection among

38:57 There's others will talk about and we into the immune system but this is

39:02 one of them. Okay um the last thing any questions. So

39:09 thing is a little bit about So this was at the beginning,

39:12 shoved it at the end. Okay because um this wasn't when I was

39:19 school um many centuries ago I um to me were always there was nothing

39:29 about a virus. When I was this there was nothing nothing about it

39:35 all that cause disease. There's nothing about. Of course that's changed.

39:39 so this is kind of what this meant to show is that viruses have

39:42 significant impact in terms of ecology. ? And so you know I think

39:48 to um intro bio um and ecology on one. Right. So the

39:56 diverse ecosystem is uh actually the healthier is um we have the contribution of

40:03 different species types in an area. lots of diversity. Um Overall that's

40:09 healthier ecosystem. And viruses can uh that that generate that in different types

40:18 ecosystems. And this is showing you marine ecosystem where viruses. So of

40:23 you have to have bacterial types in waters. You have periodic microbes,

40:30 , etcetera marine waters. And so that infect these types. Okay,

40:36 they're bacterial viruses, whether they're eukaryotic , they affect their particular hosts,

40:42 they allergy or whatnot? And uh destruction of those cells leads to production

40:49 organic materials. Right? Destroy that's organic materials and you those are

40:54 available for others to eat. So that in itself provides organic material

40:59 can help feed the ecosystem. Um also the viral infection can just go

41:05 the next slide here. Can um is what we're talking about here.

41:10 the this viral shunt, right? the eating or the infection of of

41:17 or eukaryotic cell types causing the degradation information organic matter that others can

41:23 You know feed feed ecosystem. But to the act of reducing these populations

41:29 can can make room for other species appear and grow and so kind of

41:35 diversity by minimizing so not letting not certain populations get too big and become

41:42 kind of lower their numbers and that availability of resources for others to maybe

41:49 diversity. That's kind of the idea . Um The other thing is so

41:53 you know. Yeah they infect a host but it doesn't mean they're gonna

41:58 them. That that doesn't happen because host itself can have one of these

42:04 , they both are evolving. So host itself although they may be reducing

42:09 to a degree, they're going to something that they're gonna be resistant.

42:13 so because viruses gonna have this effect the ecosystem, that doesn't mean they're

42:17 populations to extinction there, reducing But the hosts themselves can evolve and

42:24 resistant so there's always gonna be that and forth kind of thing.

42:29 But overall, you know viruses of type do help maintain ecosystems. Okay

42:36 in your own gut as well. so um so viruses aren't all bad

42:43 here. Okay, um, any ? It's actually probably a good segue

42:48 we're talking about nutrients and uptake and leads us into metabolism. Alright.

42:55 , um, so first I know metabolism you think, oh my

43:03 it's like a bazillion reactions and a enzymes have to memorize and uh organic

43:11 and this and that. Uh but I'm not gonna expect you to

43:18 every reaction. I don't even don't approach it that way. Okay,

43:23 it's more about the stages of what goes in what comes out,

43:27 the energy production kind of a So, um, to me,

43:32 me just flip the slide here, actually gonna start with that kind of

43:37 question. I'll come back in a . Well, I'll put it up

43:40 I'll talk while you're answering this kind a metabolism knowledge question and what do

43:46 recall or think you know about Or don't know. Whatever.

43:51 So while you're looking at this. I think as a I'm assuming everybody

43:57 here is a bio major or Okay, so I think there's certain

44:04 when you leave this place university as bio person that you should know.

44:11 , I don't mean no to the degree and you know, every

44:15 I mean just the conceptual knowledge of of central dogma. Right. How

44:24 flows. Right? How um basic principles. Right. So these things

44:32 should know. Okay, you don't to come out here and go,

44:36 his auto trophy? You know? would be horrific. I would don't

44:41 me. Don't tell me that. , so, well, I'm gonna

44:48 this tube in away. I hope not going to be make you

44:51 Okay. Yes. Ah Sorry, . Okay. Yeah. Real bio

45:32 . Okay. All right, counting . Okay. Um Yeah, it's

46:00 a lot of people. Yeah, most the two most popular answers are

46:04 That's fairly consistent. So, um oxygen you hail, hail, the

46:12 you inhale is converted to water is . Okay. Um That's that's that

46:21 except er right, auction terminal except respiration. So G is correct.

46:27 are all are true statements. So, uh I'm assuming you ate

46:36 donut. Maybe you didn't need a this morning, but uh whatever you

46:40 today, that's what your body sees basically as Okay, so, let's

46:49 way I do this um Like, I said, I'm not gonna expect

46:57 to memorize every metabolic reaction That's covered Chapter 13 or 14. It's more

47:08 going on, Because you can always to a book and find what what

47:12 enzyme and the specific reaction are. approach is more. Can you find

47:17 right book on the shelf? And no, kind of what's the

47:21 of that book if you want to up an individual action. Fine,

47:25 ahead. But it's more the somewhat you go into a little detail on

47:31 things. But not not memorizing all reactions. So, anyway, so

47:35 of what's going on here? So, if you think of bacterial

47:39 and culture growing, right, you , you talked about this in chapter

47:45 I think. Um so you produce of cells. Remember? This represents

47:49 of protein synthesis going on lots of replication, lots of energy requiring

47:57 Right? So this is going to something to supply that energy.

48:03 If you're growing and growing and Okay, So remember that the overriding

48:12 that has the biggest influence and this a carbon source. Okay. And

48:16 can come up obviously in a variety different forms. Right? So in

48:20 chapter 13 is pretty much focusing on hetero trophy. Right? If you're

48:28 scratching your head about a trophy, what you are. Okay.

48:36 Yes. Um so when you eat , you're likely eating all for these

48:42 and a bunch of other stuff. . And your body processes.

48:46 So um obviously, talking about energy conversions, right? Running energy

48:53 molecules and forming transforming into other types molecules. Okay, um and so

49:02 you can't biology cannot use the energy say burn something, right? You

49:09 burn glucose and get lots of energy that, but we can't use heat

49:14 that way. Obviously we would blow . We do use heat by heat

49:18 of metabolism for something else. What we use it for? Yeah.

49:25 . Body temp controlling your body So that's what makes us a endo

49:30 . Alright. Endo therms. So actually we use we do use

49:34 heat from chemical reactions to control our temp but we don't use them in

49:39 themselves to make a reaction going to . Okay. So um and so

49:46 we capture energy. Right? And you see so many reactions occurring like

49:51 from glenn calls through respiration is we're breaking down the molecule and then capturing

50:00 at different points and we can't do all at once or if you do

50:05 all at once it's actually kind of . You lose a lot of so

50:09 heat that very little is captured. we do it in increments and capture

50:14 at points along the way. And um and there are I know

50:20 familiar with uh I already answered that . It is a head or a

50:25 . Okay. Remember autotrophs? C. 02? Okay. Um

50:33 the uh I lost my train of . All right, I'll just keep

50:37 . So um everybody is aware of teepee. Of course. Right?

50:43 there's other energy molecules that we're gonna . Alright, there's the N.

50:49 . D. H. Okay. F. A. D.

50:54 To primarily that. Right? That not a big energy carrying molecule.

51:00 it's really about those two. And will lead ultimately these will lead to

51:10 lots of a tps as we'll Okay, so um the So the

51:19 we go through this process, Think about in terms of don't focus

51:23 much individual reactions necessarily. But what's stages that we're going through as we

51:28 ? And so like I said, is its metabolism? Okay. Um

51:35 uh can robotic process, soak anabolic , release energy. Okay. And

51:43 so what we're doing in a tropical taking complex organic materials, right?

51:47 lipids, carbohydrates, etcetera. And so what are we doing when

51:53 say we're producing these energy molecules? , Where is the energy actually coming

51:59 in the molecule? Where? What's you say bond? Right.

52:11 . Breaking bonds. Breaking bonds, are electrons sharing of electrons. So

52:17 capturing energy through really oxidation. And reductions are big in this

52:24 Okay? Um so redox reactions. so we're carrying electronic carrying energy.

52:31 . And so in real reactions, gonna form in the N A.

52:37 . E. Is the electron carrying . So we're going to reduce N

52:40 D N A B H. And also F E G H two.

52:46 . And so there's going to be main energy carrying molecule that we're going

52:50 do something with. Okay, so is what in essence what hetero tropes

52:56 organa tropes same thing. Right. now in fermentation, okay, we

53:04 doing what's called an incomplete oxidation. when you when you um break down

53:10 uh a carbon source and fermentation you're taking it all the way to

53:15 02 and water. Right? As do in respiration. Right? You're

53:20 to molecules like this right? In by definition is also no auctions.

53:25 . Right? So metabolism without Remember pasture. Okay, so um

53:30 the end product of things like acetic , formic acid, ethanol butin all

53:38 your c wants to see fives you to see four more common. Um

53:46 with these uh in products there's still lot of energy left. Okay.

53:51 bacteria can grow on acetate, bacteria grow on ethanol. So we know

53:57 energy still there. Okay. And can just see it in terms of

54:01 in contrast to C. 02, sio two is super stable.

54:07 Company break down SEO to write biological . Okay, so um but certainly

54:14 lots of energy left in these molecules that are in products of fermentation.

54:18 , that's the nature of fermentation, um produces less energy because of the

54:24 they do their metabolism and they end with products that have um energy left

54:30 them. Okay. So uh to a fermenter doesn't mean they can't grow

54:36 high density they can if you give enough of their carbon source. Um

54:44 they also have another thing they're And that's the end products themselves can

54:48 inhibitory. They're producing acids, These chemicals are inhibitory. So fermenter

54:54 to deal with that as well. . So um but let's talk about

55:00 later. So let's put that on shelf for now. But the point

55:03 uh um in respiration we are capturing lot more energy compared to fermentation.

55:10 . And so um and we produce energy carrying molecules, right? In

55:18 , the only energy you're producing is the form of A. T.

55:22 . Okay. And it's much Much less. Much much less.

55:28 . Um but we produce lots of in respiration. Okay. And the

55:34 about although comparatively speaking, fermentation looks basic and it is compared to

55:41 Respiration involves several stages, a lot reactions uh different processes, right?

55:48 have um electron transport system comes into . Okay, that's where auction has

55:53 role. Right? If your aerobic , the other thing to remember is

55:57 bacterial archaea world. Alright. You the ability to use things other than

56:04 . Okay, nitrate respiration is very . Uh You can use other things

56:10 um iron even and so forth. a lot more diversity with precarious compared

56:18 us. Okay. In terms of . So um so we have so

56:24 feeding this thing. Right? So have uh the process of respiration or

56:30 both require a source of food, ? An electron source. Okay.

56:38 feeding the feeding the engine, so speak. Okay. And uh and

56:43 the respiration. We have a terminal . Okay. For us it's oxygen

56:48 ? Or something else? If you're a robe. Right. So this

56:52 the a robe. Oxygen and a . Something other than oxygen.

56:56 Arab and arab. Okay. And um so photo retro. So you

57:01 like I said for the most in chapter 13 this is basically what we're

57:05 on. Are these two process respiration fermentation? Okay. We'll look at

57:11 14. We'll look at photosynthesis and trophy. Okay. But we do

57:16 while we're here head or a Photo hetero trophy. Okay so the

57:21 word there is hetero trophy. So is likely with with photosynthetic organisms.

57:28 Oh they fix C. 02. . Which is true. But your

57:32 patrols don't they can't fix co. . They still have to have organic

57:37 . Two as a carbon source. they can get energy using photosynthesis.

57:43 . So they have the ability to a TPS using light but they still

57:47 organic carbon for their source. Um and so again, we already

57:52 different things can be used for Different types of organic carbon sources.

57:58 . And so uh so last again is what we look at this

58:03 These processes in chapter 14. So but just to mention here

58:09 Right. So completely inorganic materials like iron H. Two S reduced inorganic

58:19 . H. Two S. Ammonia . Service energy sources for little tropes

58:24 Mogens can use hydrogen. And so um but again, most of these

58:31 also autotrophs. They have to have . 02 as their carbon.

58:36 so again, so the question the energy for this right, comes

58:42 either light reactions. That's a photo trove. Okay, Or from oxidation

58:49 inorganic materials like I just mentioned Two S etcetera. That's your lift

58:54 trophy or chemo water trove. Same thing. Okay, so uh

59:00 this is the last So I'm not mention this again until we get

59:04 Right? But just you know, for completeness, throw it in

59:07 So let's look at let's look at question. Okay, so respiration.

59:15 what you remember about respiration. So does it not require on this

59:23 Okay, what does it not I'm pretty sure you're gonna get this

59:33 100% on this one prediction. Uh Can be lots of things.

60:02 . Be a donut. Don't overthink . That's the that's the lesson.

60:27 . Mhm. Already too. here we go. Yes, pretty

60:38 . It is all required. All . So and I'll uh show you

60:48 here in this uh diagram. So gonna see this um diagram a lot

60:56 the next two weeks. Okay. I'm gonna add to it. This

61:02 kind of a basic form of It's not basic. Okay, um

61:10 gonna add to this. But so point here is Okay, um and

61:18 got some questions coming up that relate this diagram. So I'm not gonna

61:21 everything yet. Okay, so the to remember here um maintain electron

61:28 Okay. You your your respiratory system you're in a robe, right?

61:34 can meet and a robe. This is still operating okay. Um

61:40 production of a proton gradient is the is really what it's all about about

61:48 , producing and maintaining in gradient is what this whole thing is about.

61:53 . Um you're basically alive because your are doing this okay, maintaining those

62:01 . proton gradients because you're gonna And the other thing to remember here is

62:07 if you maintain a proton gradient, maintain a TP production. And so

62:14 I realized I'm not getting specific here I have I'm gonna throw in some

62:17 first. Before I get more Okay, So then becomes how do

62:22 do this? How do we maintain ? Right. And what do we

62:27 to maintain? Okay, I'm being little bit cryptic here, but there's

62:32 point to that. Um and so , it's all about redox reactions.

62:36 reactions involved, of course, molecules give up electrons and the process become

62:42 and those that receive those electrons become . Okay, so, and both

62:47 things go hand in hand. And so it's it's respiration is full

62:52 these things. Okay. And so thing to remember. Is this all

62:57 ? A couple of energy requiring processes energy reducing process. That's what that's

63:01 we're doing all the time here in . Okay. Because it's it's it's

63:08 , you can say well, if something needs energy, let's just

63:11 it a teepee and that will Right? That's not that's not always

63:15 most efficient way to do it. other ways to do it,

63:18 And so where you can do things maybe save a tps or other processes

63:23 that's more efficient. And we'll see that happens. This concept happens time

63:29 again. It's happening on this diagram here in multiple ways. Okay.

63:38 . Alright, so again, I I'm being a little bit. Uh

63:42 really everything yet, but there's a to the madness. Okay. All

63:47 , so here's question one. We are inside E. Coli if

63:54 e coli anaerobic clear aspiring. Um location? 12345 would easily indicate slash

64:09 show this to us deposit. oops. This one. There we

64:21 . Okay, So areas circled areas . Is this anaerobic or aerobic?

65:03 . Okay. We're not sure. okay. No crime. Alright,

65:16 Down From 3 : one. Um I'm gonna answer this. Let's

65:29 move on. Okay. Okay, a minute. Is that I have

65:38 have another question. Let me just consult the oracle here. Um Oh

65:48 . Oh yeah, you said. , hold on. Okay, here's

65:52 question. All right, sorry, are inside the bacteria were still inside

65:56 . Coli no, we're not inside coli because it's not a little

66:01 This is more like a trophy. location would be looked at to

66:07 It's a little trophy. So you to look at the same, same

66:12 , same labeled sections. Now, question is it's a little trophy.

66:17 would you know that? Where would look? What would you look to

66:21 that out? Yeah, that's the question. Okay, so this time

66:52 it's a little trophy. How would know that? What would I look

66:55 assess that? Okay. All counting down from nine. So make

67:03 pick. Even if you're not 7654. Here we go. All

67:19 , nice. Okay, so, here, here and here. These

67:32 two locations. So this was this truth or not the trophy or Head

67:41 12 maybe. Okay, let's look the head trophy. Look there a

67:49 and a real question mark. You there. Okay, so of course

67:57 differentiating between the donor electron donor for whole process, which is a a

68:03 the reduced form oxidized X. Um electronic and they are going to electronic

68:10 chain electron flow is important. So gonna ultimately go to a terminal except

68:16 which is be reduced picking up electrons to G. So that be can

68:23 oxygen. It could be something out the action nitrate, what have

68:27 Okay, so the point of this uh that that I just mentioned electron

68:35 . Right? You have a donor this whole process and um something at

68:40 end receiving. Um and in the , let me just I'm gonna go

68:44 gonna go ahead up to here. remember this. Right, right,

68:49 requiring energy releasing go together. So, I'm gonna put this all

68:53 here. Okay, so membrane super because if you're trying to maintain a

69:03 gradient is about, you know, from high to low concentration, right

69:09 difference. Right? The membrane allows to kind of differentiate that.

69:14 So you stuff molecules on one side a higher concentration than the other and

69:18 membrane Of course, that's what allows to do that. Okay, the

69:23 of the membrane also allows you to maybe some potential energy there because we

69:27 a gradient with molecules that are right? They can't come easily back

69:32 a membrane. Right? They repelled the membrane. Right, so that

69:36 sets up like some kind of potential difference as well, high concentration outside

69:40 in they can't get in because of membranes to two hydrophobic. Right,

69:46 now you have some potential energy that can do something with if you allow

69:49 to come in. Right, so to that in a second. So

69:54 transport system. Okay, again, into a membrane. Right uh you

70:00 stuff a lot of these into a . So the action of respiration occurs

70:04 with the membrane for that reason. . For the senses the same way

70:09 stuff into a membrane. Okay. we have electronic transport system. So

70:14 have to feed the electrons of Right, so that's where the electron

70:17 comes in. So you have to between two things. Think of this

70:22 a food. This is a food . This is a donut.

70:27 Um ultimately becomes oxidized. Right, we have digestion of course that breaks

70:33 large particles are small but then we to get to molecular scale.

70:37 So break it down like into glucose other carbohydrates and what have you Right

70:45 , is it organic or inorganic? your little trophy versus Peter trophy if

70:50 trophy difference. Okay, now, that source. Right, of course

70:58 example all the time for this Right, so glucose is the source

71:04 glucose doesn't interact with the electron transport directly. Right, Michael gets oxidized

71:11 steps are gonna capture the electrons using guys right in A. D becomes

71:17 to N A. D. These are the things that will interact

71:21 interact with electron transport chain. so while this is the source of

71:26 of the electrons the electrons are actually via these N. A.

71:31 Going to N A. D. molecules. Okay. And so now

71:35 feed the electron transport system. And this is comprised of various components

71:41 components that each pick up and then off electrons to its partner.

71:46 And so this is an energy coupling . Transfer electrons releases energy.

71:53 And that energy is used to pump out as we'll see electron flows to

71:58 terminal except er. Okay. And maintain electron flow is essential.

72:04 So it's aerobic can be oxygen and , something other than oxygen.

72:10 And so you can probably reduce, have molecules on this side of front

72:17 say left side that are better at off giving up electrons. We call

72:23 donors right? And progressively to stronger stronger except ear's. Right. So

72:31 markets that like to give up electrons to those that more progressively like to

72:36 electrons. And when you have a like that you maintain flow.

72:42 And oxygen is the most biological The most highest affinity for electrons.

72:48 we call highest reduction potential biggest ability grab electrons is oxygen. And that's

72:55 of the reason why electrons flow that and they flow. The energy released

73:00 transfers pumps protons out. Okay, that then so here's your potential energy

73:07 these things can easily cross the membrane charged won't go through unless you give

73:13 a conduit. And that's a P. S. A. T

73:17 in place. So this this force both a force due to electrical attraction

73:24 the inside of the cell is negatively . And also the concentration difference.

73:29 the proton motive force are both those . And so energy releasing process protons

73:36 down a gradient, energy requiring process a. T. P.

73:41 A couple of those things together. make lots of 80 P.

73:45 So it's all about flow. If don't believe it, there's an easy

73:49 to test that. Get a plastic , put it over your head and

73:56 that. Okay, you will You'll stop that, right? And

74:05 stops everything up. You're dead. right, folks. See you go

74:11 the lab, see you next I think about that. You don't

74:17 sons.

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