| 00:00 | Yeah. Yeah. Right. OK. Testing. Testing, |
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| 00:48 | testing. OK. Folks welcome the before the storm. OK. Um |
|
| 01:02 | everybody doing? Um Yeah, I everybody does well tomorrow on the exam |
|
| 01:15 | , or Saturday whatever day you're taking , um, still available for last |
|
| 01:21 | questions. Um uh talk you off ledge if necessary, but that's a |
|
| 01:29 | , shouldn't say that. Um you , relax, take a deep |
|
| 01:35 | OK. That's what I'm trying to . So, um something. All |
|
| 01:45 | . So today, what we're talking today is on the exam. |
|
| 01:50 | So, II I assume you know , but uh today we are starting |
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| 01:56 | two, starting it today. Uh hope you at least flip through the |
|
| 02:06 | lecture for this material, right? today is one of those flipped Flippity |
|
| 02:12 | classes. OK? They're gonna need lot of questions. Uh started on |
|
| 02:19 | three stuff in time. So approximately , uh 56789, 9, 30 |
|
| 02:38 | , 10 if we get that 10, 11, something like |
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| 02:41 | 11 questions if we get that Um But we're gonna start the discussion |
|
| 02:47 | that, right? So we have talking about uh metabolism, right, |
|
| 02:54 | various contexts, contexts, right? uh the uh like like cause cell |
|
| 03:04 | , he autotroph phototropic and then uh into the aero tolerance, right? |
|
| 03:12 | microbes behave in the presence of oxygen ? Um um and then finished up |
|
| 03:23 | uh a little bit about microbial so to speak nitrogen cycle. So |
|
| 03:29 | , all that's metabolism as well, ? And so now in this |
|
| 03:36 | which is uh three chapters, 34 and six. OK. So |
|
| 03:44 | the you know, and metabolism is gonna be a part of the things |
|
| 03:49 | really talking about in this unit. uh not to the same degree, |
|
| 03:54 | there's gonna be some applications of So especially in in in chapter uh |
|
| 04:00 | chapter on growth, right? Because that goes hand in hand with |
|
| 04:04 | OK. So um so, oh should say remember there's no, no |
|
| 04:13 | quiz this week, no weekly quiz worry about no smart work assignment. |
|
| 04:17 | um so just focusing on the But then of course, today taking |
|
| 04:22 | little break from the unit one So today and next time is about |
|
| 04:27 | cell. So now we're going inside pro Caro cell um and outside because |
|
| 04:34 | gonna kind of start books, do different ways, books, you |
|
| 04:37 | some start on the outside and go and different variations, right? So |
|
| 04:42 | chapter is all about um if it's is a really easy one to see |
|
| 04:49 | you get it all is at the , you just draw a circle or |
|
| 04:55 | your favorite microbe shape is, Oops. Favorite. Um So busy |
|
| 05:00 | for a second. Um Favorite pro shape is right? Is the |
|
| 05:04 | is the circle, whatever. Just draw that. Just draw that |
|
| 05:08 | your paper and you go OK. do I know about this? |
|
| 05:11 | Well, it can have a cell . If it has a cell |
|
| 05:14 | it may be looks like a gram envelope or gram positive blah, |
|
| 05:17 | blah. And she just how much can fill in on that. That's |
|
| 05:20 | indicator of what you know, because really what we're doing here in, |
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| 05:23 | three years. Here's the features in pro cell, here's what it |
|
| 05:28 | And so basically a list of those . OK? So um four is |
|
| 05:35 | growth, six is about viruses. ? So that's unit two. And |
|
| 05:40 | let's uh uh before we go any questions on anything, any questions |
|
| 05:46 | it. OK. Anything at OK. All right. So let's |
|
| 05:51 | here. So this is what we're . OK. So proo cell um |
|
| 05:58 | while I'm here, I'm at the of you that are in lab. |
|
| 06:03 | ? Those of you in lab. I noticed this week that um if |
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| 06:08 | not in lab, you're probably it's only because you didn't get, |
|
| 06:11 | weren't able to enroll this semester. you'll probably be enrolling next semester. |
|
| 06:14 | , still applicable is, or maybe already taken lab? Ok. Is |
|
| 06:20 | already taken lab? Taking lab? . So if I, you, |
|
| 06:27 | , you, this week you did um stains, right? You made |
|
| 06:30 | slide, right? And so I show here's a plate, right? |
|
| 06:34 | got growth on it, right? so you take a wire loop, |
|
| 06:40 | ? And you take some of the , which is the best way to |
|
| 06:43 | it. Take your loop and go right through all the growth and make |
|
| 06:48 | slide from that. Is that what would do? What would you |
|
| 06:54 | OK. Now we're talking about making slide and thinking of some of that |
|
| 06:58 | . OK. Are you gonna streak your whole loop through all the all |
|
| 07:01 | growth on the plate? No, touch it, just touch it, |
|
| 07:06 | at the plates uh this morning that used, streak marks all through the |
|
| 07:12 | , right? Get the idea is concept here is um to look under |
|
| 07:17 | make a slide, look under the , even to inoculate another plate or |
|
| 07:22 | liquid medium. You don't need to a blob of stuff. Trust |
|
| 07:28 | you can just touch it, you'll tens of thousands of selves. |
|
| 07:34 | So less is better, especially if making a slide. So remember |
|
| 07:40 | OK. Um There's a lot of in microbiology that that are seem fairly |
|
| 07:47 | but a lot of it to do , do it well, it takes |
|
| 07:50 | little bit of touch to it. . So, um, you don't |
|
| 07:54 | to see a big blob to know there. You just gotta touch |
|
| 07:57 | you know? And, you you don't have to see microbes and |
|
| 07:59 | they're, they're there. You get , right. Do you ever see |
|
| 08:02 | things coming at you to make you ? No. Ok. So |
|
| 08:08 | let me get off that soapbox. right, back to the bacterial |
|
| 08:12 | OK. So uh basically, I list of all these things here and |
|
| 08:18 | more uh but you know, gonna familiar with this and so the the |
|
| 08:22 | , that term bacterial envelope. So first question relates to that. So |
|
| 08:26 | gonna go through all these structures and Caro um what makes it up? |
|
| 08:32 | makes it tick and um various functions so forth? OK. So let's |
|
| 08:38 | at this first question. All let me get this over here. |
|
| 08:43 | while you're looking at this, as do have, I was looking at |
|
| 08:46 | earlier and I do have one slight to make about the envelope. |
|
| 08:54 | Um So, uh so this is which is true regarding a bacterial cell |
|
| 09:04 | . Um And then we'll get into kind of the definition of that. |
|
| 09:11 | . So I'm gonna go ahead and the timer since we had a bunch |
|
| 09:15 | these here. I'm kind of kind go through them uh once the clock |
|
| 09:21 | up here chime. Mhm. Ok. Counting down from 11 |
|
| 09:49 | 11 10 98. Hm 210. . All right. Um The let's |
|
| 10:10 | at the definition here. OK. the envelope. OK. Um |
|
| 10:21 | Whatever the dinging is who's dinging? gotta ding it's driving me insane. |
|
| 10:27 | . All right. So the So are you we used to people |
|
| 10:31 | to say, oh what kind of walls the bacteria have? OK. |
|
| 10:35 | may have that but they may have things in addition to that. |
|
| 10:40 | So is more correct to use the envelope because that refers to what's |
|
| 10:48 | what's, what's what's external to the membrane, right? The plasma |
|
| 10:54 | if you will the the membrane that the cell, right? There's, |
|
| 10:58 | there's that that membrane main membrane if will, but then bacteria can have |
|
| 11:04 | is beyond it. That's the OK? But in thinking about that |
|
| 11:10 | , the the inner membrane itself is of that as well. OK. |
|
| 11:17 | I'm gonna slightly amend this and you know it, it the the |
|
| 11:21 | also includes that inner membrane, So what is it? What is |
|
| 11:28 | like? 10 here it is, a, here's our membrane. So |
|
| 11:33 | is it? That's my pen is working there we go. What is |
|
| 11:40 | ? That's all out here. What's there now being a cell you're gonna |
|
| 11:46 | you're gonna have that. All OK. That's why you may have |
|
| 11:49 | a little bit um uh confused by you pick C or didn't pick |
|
| 11:55 | right? The answer is all of A B and C. OK. |
|
| 12:00 | we're saying that the inner membrane is , right? But it may not |
|
| 12:04 | a wall or may have a wall other stuff. OK. So because |
|
| 12:09 | are bacteria that lack a cell OK? But a cell is not |
|
| 12:13 | cell, it doesn't have a right? That's what defines, that's |
|
| 12:17 | thing that defines a cell. You have a membrane. OK? But |
|
| 12:21 | you may have other stuff, other components. OK. So um you |
|
| 12:27 | look at answers c and go Well, it doesn't have anything. |
|
| 12:30 | right, has no membranes, right? But, but, but |
|
| 12:34 | meant to by this, I meant say it only has a membrane and |
|
| 12:39 | else and there are bacteria that are that. OK. So I just |
|
| 12:42 | make that distinct. OK. Is clear or is that, does that |
|
| 12:46 | it worse? All right. So what needs to be changed? |
|
| 12:53 | anything that is? So it could uh a cell wall is a chemical |
|
| 12:58 | . It could be um an outer . So gram negative has an outer |
|
| 13:03 | in addition to a cell wall. all those are chemical components that |
|
| 13:08 | that include the that core membrane, associated with it if we're the |
|
| 13:20 | which is why I pointed out c maybe. Yeah. Right. |
|
| 13:24 | Exactly. That's why I wanted to that. So, yeah, because |
|
| 13:28 | never have a cell that had nothing there, right? It wouldn't be |
|
| 13:31 | cell, right? So what I trying to, so that's why I |
|
| 13:35 | to kind of amend that. So I say cell envelope, it also |
|
| 13:39 | actually include that membrane. OK. OK. Any questions about that? |
|
| 13:47 | . So one more time this is basic cell, right? So we're |
|
| 13:51 | call here and including the membrane. out here? OK. What |
|
| 14:01 | what are the components that are Right? Maybe it's nothing, maybe |
|
| 14:05 | just that just the memory and that's . But maybe it has some other |
|
| 14:10 | out there. So we're gonna see variations. OK. So um |
|
| 14:18 | So true regarding a bacterial envelope, could contain another membrane, it could |
|
| 14:22 | a cell wall, it could contain but just the membrane itself, nothing |
|
| 14:28 | external to it. OK. So are the options there. OK. |
|
| 14:34 | All right quantities. So now it's um the molecules making up a cell |
|
| 14:45 | pro cell, OK. Or Archaea forget about them, right? Archaea |
|
| 14:51 | . So um so this is asking quantity molecules for a cell. |
|
| 14:59 | The most abundant in the bacterial cell OK. Come down to 10 |
|
| 15:39 | Oh Yeah. Yeah. Yes, is water. OK. Water |
|
| 15:45 | OK. So, I mean, gonna be the same answer for any |
|
| 15:50 | thing. All right, it's, is full of water. All |
|
| 15:54 | 70% water, more or less. . The water molecules. Uh |
|
| 15:59 | certainly DNA is, you know, be the biggest. Right. |
|
| 16:04 | Most visible perhaps. But it's just molecule in a bacteria. It's just |
|
| 16:09 | for the most part, right? chromosome and a bacteria. Um So |
|
| 16:16 | what I call it information the molecules the cell proteins. Uh RN am |
|
| 16:22 | A et cetera. The the box that amounts to about 25% quarter of |
|
| 16:28 | cell components. OK. Um oh DNA as well in there. The |
|
| 16:37 | and so things of course, like and, and metabolites molecules that make |
|
| 16:43 | the the different metabolic pathways and of course, are part of this |
|
| 16:47 | the, in the cytoplasm. Um fossil lipids making it membrane. Um |
|
| 16:56 | uh that amounts to about maybe OK. Uh This group here. |
|
| 17:03 | so the um the uh question here . So these, these, these |
|
| 17:11 | here are all for an eco an coli. OK? An E |
|
| 17:16 | And for most of these numbers, not gonna differ that much from one |
|
| 17:21 | or archaea to another. But you see some difference here in this constituent |
|
| 17:28 | glycan. OK? Pepto glycan is cell wall material. OK. So |
|
| 17:35 | coli has that value of, of percentage total weight of 0.8%. |
|
| 17:43 | Um why is staff has a number much bigger than that. So that's |
|
| 17:49 | of what staphylococcus versus E coli. , it's grand positive. Staff is |
|
| 17:55 | positive. So it's gonna have they a lot more of this pep I |
|
| 17:59 | material. Ok? So as we'll . Ok. Um ok, so |
|
| 18:06 | is one that people always get kind fishy about, ok, you covered |
|
| 18:11 | concept in intra bio, I'm pretty . So here we have a liquid |
|
| 18:15 | of E coli uh incubating at 34 . OK. You increase the incubation |
|
| 18:24 | to 42. So eight degree Um So which picture are, you're |
|
| 18:30 | see it in a second uh with inner membrane of E coli most closely |
|
| 18:36 | after it responds to the temperature change it will respond. OK. So |
|
| 18:42 | go to 42. OK. You like A or B. So |
|
| 18:47 | another thing to think about is why it, why does it? |
|
| 18:54 | It's bad English. Why does, it, why does it need to |
|
| 18:58 | ? OK. So, and it OK. So we're at 34 we |
|
| 19:05 | to 42 and makes a change. it gonna look like? OK. |
|
| 19:10 | Let me open this up. Sorry answer. OK. Yeah. Do |
|
| 19:47 | ? Hm. Um OK. Counting . OK. So let me pause |
|
| 20:13 | three seconds. See if I can you out. All right. So |
|
| 20:18 | at 34 degrees, that's what our looks like. So if um we |
|
| 20:23 | up the temperature several degrees, that thermal energy will translate to kinetic |
|
| 20:31 | , right? The molecules will begin kind of bounce around more now, |
|
| 20:36 | ? And uh and in doing right, bouncing around um maybe create |
|
| 20:42 | space in between the members, the , right? So that bouncing |
|
| 20:51 | you know, creating maybe more space sometimes, I mean, not so |
|
| 20:55 | that what can happen as disconnect energy really making those micros bounce around. |
|
| 21:04 | ? And something come in out of cell more easily. Yes. |
|
| 21:08 | you get leakage, right? So kind of temperature change will increase, |
|
| 21:15 | attempt will cause those connections to kind cause these molecules kind of bounce around |
|
| 21:20 | , right, more freely. And those are opportunities for stuff to come |
|
| 21:24 | and leak out. So what's the to fix that? Right? So |
|
| 21:30 | you are, if you want to your mind, change your mind |
|
| 21:33 | OK. So we're gonna go Boom. Oh OK. I clear |
|
| 21:45 | the correct answer is a just Anybody. OK. You in the |
|
| 21:54 | . Hold on, let me come , let me come to you. |
|
| 21:57 | right, you are correct. you know why you picked a if |
|
| 22:03 | were explaining everything bouncing around, hold . All right. What do you |
|
| 22:08 | ? OK. So I picked a there's more leakage so that, |
|
| 22:12 | the cell memory they need to be so that the leakage doesn't affect |
|
| 22:17 | um, uh, compromise the function the cell. Correct. Very |
|
| 22:22 | Give her a hand. All So you were saying what you need |
|
| 22:31 | respond to the, yeah. Right. Exactly. Right. So |
|
| 22:37 | pick a, OK, good. . Correct. So that's, that's |
|
| 22:41 | going on. So, ecoli doesn't , it wants to counteract this effect |
|
| 22:47 | occurring because the kinetic energy and causing uh molecules to lose their associations with |
|
| 22:57 | neighbors, right? It wants to those associations with those neighbors. |
|
| 23:03 | So the way to do it if a fossil lipid is to um you |
|
| 23:08 | , because they rely on hydrophobic right? Get the hydrophobic parts |
|
| 23:13 | right? And create less distance. so you, you, you decrease |
|
| 23:18 | distance by by changing number one, this, right? Those little |
|
| 23:24 | right? Those are due to uh bonds that are in the chains creating |
|
| 23:28 | king. So get those out, . So, and, and so |
|
| 23:32 | you recall, you know the right? Saturation, you saturate your |
|
| 23:39 | acid legs, if you will, ? The fatty acid chain, you |
|
| 23:43 | those double bonds out and make them straighter. And that's what the effect |
|
| 23:47 | to take the double bond out is make it as straight now and that's |
|
| 23:51 | allows them to kind of come Now, I've, I'm, |
|
| 23:55 | I'm slightly exaggerated in A and B for effect. Just to show you |
|
| 24:00 | , you know, the goal is kind of make it more tighter if |
|
| 24:04 | will to reduce leakage. OK. there will be a, the point |
|
| 24:10 | the proportion of the degree of saturation change. OK. To make those |
|
| 24:15 | acids come together to prevent, you , the, the leakage that's occurring |
|
| 24:19 | the high temp. OK. And um it wouldn't want to increase. |
|
| 24:25 | B is basically, is basically promoting the formation of more double bonds and |
|
| 24:33 | keep things apart, right? So is kind of worsening the problem than |
|
| 24:38 | it. A is helping the What's going on with it. |
|
| 24:42 | And so these things happen very they happen on the fly. |
|
| 24:47 | You can, you can change, this and uh um you know, |
|
| 24:52 | not just bacterial cells that do you know anything with a membrane can |
|
| 24:56 | this. OK. And so um there any questions about that? Does |
|
| 25:01 | makes sense? I in saying? , don't answer that. OK. |
|
| 25:07 | So that's the idea just to, just as well, you could go |
|
| 25:11 | , you could be freezing. And the membrane can actually uh |
|
| 25:17 | Oh Sorry. Wow. Can really together too much and, and actually |
|
| 25:22 | . OK. So that too can uh because remember the membrane, I'm |
|
| 25:28 | showing it here, but the membrane full of proteins, right? And |
|
| 25:31 | help molecules get in and out, can have enzyme functions, et |
|
| 25:35 | And so you can affect their functioning well. And so freezing, it |
|
| 25:40 | also have an effect. So you of wanna trace of space as |
|
| 25:45 | right? For optimal function. So um and so just briefly about |
|
| 25:52 | membrane, right, we've all, all had this before about membrane |
|
| 25:56 | fossil bio layer, the fluid mosaic . you probably heard those terms. |
|
| 26:03 | I'm not gonna go into all Uh you know, the core of |
|
| 26:06 | membrane structures, these fossil lipids and have both water loving and water heating |
|
| 26:11 | , red collar, nonpolar and they together, they form a bilayer and |
|
| 26:17 | proteins within a membrane are what provide functionality. OK? Um Because membranes |
|
| 26:25 | be very different in terms of what can do, right? Mitochondrial |
|
| 26:30 | for example, right? Full of enzymes, right? Um uh photosynthetic |
|
| 26:37 | , full of photosynthetic pigments, et , right? So um the the |
|
| 26:44 | membrane of a bacterial cell, uh functions on different parts of the |
|
| 26:50 | OK. Um So it it it's about the proteins and it's roughly probably |
|
| 26:56 | 1 to 1 protein to fossil 1 to 1 or 4 60 40 |
|
| 27:02 | in there. OK? Um Because what's needed. So remember the the |
|
| 27:07 | of the fossil lifted bilayer itself is selective permeability, right? And so |
|
| 27:14 | only only certain things can come in out of a fossil lifted bilayer or |
|
| 27:19 | that. And so to, to of really um allow other types of |
|
| 27:26 | in and out and other functions, you put proteins in it. |
|
| 27:29 | So, and the proteins kind of what, what the functioning of that |
|
| 27:33 | is and can be. OK. um OK. The what to know |
|
| 27:41 | in terms of uh so we just about, so here's what we talking |
|
| 27:46 | the the creating pinks, right? bonds do that, right. So |
|
| 27:51 | versus um cyst versus trans, for , straight chain or pink chain, |
|
| 27:57 | ? So that's kind of influences the of the membrane. But bacteria can |
|
| 28:03 | do this, right? They can these cyclic uh connections with these fatty |
|
| 28:09 | , right? And that too promotes of the straight chain confirmation. |
|
| 28:15 | Also helps keep maintain integrity of that by having these cyclic types of |
|
| 28:22 | Um A Kia membranes, right. they have um these di Glycerol di |
|
| 28:29 | molecules, OK? Especially the type their that are thermoph fis and hyper |
|
| 28:35 | files live at extremely hot temperatures. ? And so these are very as |
|
| 28:41 | can see, very hydrophobic, they're just hydrocarbon chain, it's gonna |
|
| 28:46 | 50 60 carbons long and they're very and they can pack together very tightly |
|
| 28:53 | they can also polymerize right, to even longer chains, right? So |
|
| 28:58 | is what enables these kinds to, live in these very, extremely hot |
|
| 29:03 | . OK. Um And a an for, for that environment. |
|
| 29:09 | Uh They too can form this, cyclic types. These are called cyclo |
|
| 29:14 | rings, but the same um function maintain the linearity of the chain and |
|
| 29:23 | it. OK. And so that them maintain membrane function at, at |
|
| 29:28 | elevated temperatures. OK. And they're thermoph files that have, they all |
|
| 29:33 | these uh dither type things, but do have adaptations that enable them to |
|
| 29:39 | temps. But you don't see bacteria are typically in the hyper Theophile range |
|
| 29:45 | archaea. OK. Um OK. um All right. So look at |
|
| 29:54 | question, turn this thing on uh now we're gonna kinda get into |
|
| 30:00 | transport stuff. I know you probably probably more, less a review for |
|
| 30:04 | , but let's just kind of go this. Uh So again, |
|
| 30:09 | and this is kind of a um number one microbes of course have to |
|
| 30:18 | in material nutrients and things to they get rid of material. Um |
|
| 30:24 | so remembering how molecules move, across a membrane that in many |
|
| 30:34 | the microbe is at the mercy of surroundings, you know, not everything |
|
| 30:37 | set up so that they have the concentrations and types they need optimally. |
|
| 30:44 | you have to do some things to counteract that. OK. So |
|
| 30:49 | guy is living in a pond with very different salt concentration, sodium but |
|
| 30:58 | in inter it's maintaining a much higher than what's on the outside. But |
|
| 31:04 | is it doing that? OK. . OK. All right. Let's |
|
| 31:36 | down from five. Remember if if the answer in your head is |
|
| 31:43 | there, then you know what you do. Sure. OK. Um |
|
| 31:59 | right. So what we're doing here sodium bac, so sodium is coming |
|
| 32:08 | the cell, the bacterium is doing . And we know so because the |
|
| 32:13 | is much higher than what's out OK? It's bringing it in. |
|
| 32:20 | think it'd be going the other right? Because remember concentration gradients, |
|
| 32:26 | ? Molecules will naturally move down right? High to low. |
|
| 32:32 | It doesn't require energy, right? so you think, well, they |
|
| 32:36 | be going this way, right? that's the concentration gradient of high to |
|
| 32:40 | but they're not, it's concentrating these inside the cell, it's pushing up |
|
| 32:46 | , right? And that's what is ? Yeah, is active transport up |
|
| 32:53 | ? No, right? So you E OK. So the so facilitator |
|
| 33:00 | , simple diffusion, not a choice . These are passive processes, |
|
| 33:06 | These um molecules move down concentration which what it's about. It's about |
|
| 33:14 | OK. Passive movement means you're you're not expending energy, you're actually |
|
| 33:19 | energy. And we know that right? Proton gradient, right? |
|
| 33:23 | come back down to a TP release and that helps you make a TP |
|
| 33:30 | . But active transport, right? being pumped out, right? Actively |
|
| 33:36 | protons that takes energy and we know already, right? Because the energy |
|
| 33:40 | do that comes from from what? , what's my little diagram? You've |
|
| 33:51 | this a bazillion times in the last weeks, electron transport chain. It |
|
| 33:55 | be throwing up by now. You've it so many times, right? |
|
| 34:00 | The energy comes from electron transfers in example. OK. So um |
|
| 34:08 | so it's active transport, we're actively protons across. OK. So osmosis |
|
| 34:14 | water movement of water molecules, pinocytosis that's the term usually for use for |
|
| 34:21 | cells and and how they can bring water in, for example, um |
|
| 34:26 | don't really have a pinocytosis. Um the the facilitate diffusion or simple |
|
| 34:32 | they're all about movements downgrade it. . Accurate transport you go the other |
|
| 34:39 | . OK. So let's look at question. OK. We'll, we'll |
|
| 34:44 | all this here shortly. OK. . So again, context here, |
|
| 34:51 | know, having talked about metabolism um you know the the molecules you |
|
| 34:58 | in there like the so electron right? You eat those eat, |
|
| 35:02 | , eat it, you take it , you gotta take these things into |
|
| 35:05 | cell. So transport processes obviously are be a critical for that and there's |
|
| 35:12 | ways things enter the cell. And so another, you know, |
|
| 35:22 | hypertonic hypotonic that can kind of confuse sometimes. So we'll mention that. |
|
| 35:59 | . Yeah. The, ok, count down from 22. I, |
|
| 36:27 | . Two seconds. Oz. Uh 10. Oh, all over the |
|
| 36:40 | . That's a good distribution. All right. Um E start at |
|
| 36:49 | bottom go up. So, e absolutely makes sense because, um, |
|
| 36:56 | saw the use of this, We're using energy here this time. |
|
| 37:01 | supplying a TP instead, right? To pump protons out. Right? |
|
| 37:10 | which way is sucrose growing it's going to high, right? So |
|
| 37:18 | that's an active process, right? how are we pumping sucrose out? |
|
| 37:23 | using the energy from protons going down gradient, right? Hi. Um |
|
| 37:34 | using the energy released from that to sucrose out. OK. So proton |
|
| 37:39 | can be used for lots of right? Making a TPS to, |
|
| 37:45 | transporting molecules. So that certainly makes , right? The old energy requiring |
|
| 37:50 | energy releasing, putting those together Uh This is D is basically |
|
| 37:57 | That's just the definition of it, ? So we'll see how that |
|
| 38:00 | So they um they do create those of problems. OK. Group |
|
| 38:07 | That's what that is. OK. diffusion. Yeah, it doesn't well |
|
| 38:13 | diffusion involves a protein but simple does . OK. Um So it's this |
|
| 38:20 | that's false. OK. So the hypertonic, OK. Actually let's just |
|
| 38:30 | about it here on the next OK. So they are your |
|
| 38:35 | right? Simple diffusion, things like , small molecules, water can actually |
|
| 38:43 | across a membrane even though it is , it's, it's small. |
|
| 38:48 | Um So those don't need help. . But the movement is based on |
|
| 38:56 | way is the gradient set up, ? So it's always gonna be high |
|
| 39:00 | low. OK. That's the movement for simple and facilitated. OK. |
|
| 39:07 | sort of these things like sugars, , amino acids, um they're larger |
|
| 39:15 | molecules, uh charged molecules as They need help, right? They |
|
| 39:22 | a specific transporter to get in, it. And again, the movement |
|
| 39:25 | based on which way is the gradient up. OK. High to |
|
| 39:30 | OK. So active transport is the one that you you can pump against |
|
| 39:36 | concentration grade um takes energy. Uh osmosis um if you need to |
|
| 39:45 | , so you can have so generally , coos and like most, most |
|
| 39:52 | cells try to keep themselves slightly hypertonic . So remember the two terms are |
|
| 40:01 | to each other. So it's hypertonic , it's hypo tonic outside. |
|
| 40:08 | And so it refers to the solute . So hypertonic high. So is |
|
| 40:12 | high solute, sub hypotonic has less . OK. So water always moves |
|
| 40:20 | the high solute side. OK? hydrate those solute molecules, right? |
|
| 40:28 | why that's why water is going there the high solute side. OK. |
|
| 40:34 | So what like I said, water move across a membrane without help. |
|
| 40:39 | if a cell is under osmotic OK. It needs to move water |
|
| 40:47 | , whether in or out or then can do so with aqua pos. |
|
| 40:51 | aquaporin help move water more quickly. . And that can, and, |
|
| 40:56 | bacteria can do that when they're, they're under stress. OK. Um |
|
| 41:02 | bacteria have many bacteria, of have a cell wall. I probably |
|
| 41:06 | do that don't. Uh And so cell wall plus being hypertonic inside water |
|
| 41:12 | in. OK. And then kind presses against the cell wall. So |
|
| 41:16 | kind of helps maintain shape and Uh plants do the same thing. |
|
| 41:23 | . Um OK. So just back this question real quick. So hypertonic |
|
| 41:30 | means a hypertonic outside and the water gonna move that way, it's gonna |
|
| 41:36 | out of the cell. OK. hypo in hyper come on, not |
|
| 41:47 | work. OK. So let me one more time here. So hyper |
|
| 41:53 | outside. OK. So we are to the high, high. So |
|
| 41:57 | OK. Uh OK. Group translocation transporters. So here uh so group |
|
| 42:06 | relies on that uh concept of molecules , independent of each other. |
|
| 42:14 | So we have glucose uh comes into cell. OK. And because it's |
|
| 42:21 | modified right, to adding phosphate to glucose six phosphate, these two are |
|
| 42:29 | molecules. OK. And um let's , try it here. So glucose |
|
| 42:36 | months, right? And glucose. if it gets modified as soon as |
|
| 42:39 | comes in and So that means the of glucose inside the cell is super |
|
| 42:46 | because it's always getting converted to the , six phosphate. So that means |
|
| 42:51 | glucose can freely come in the right? It keeps coming in as |
|
| 42:56 | as it's rapidly converted. Ok? we didn't have this, right? |
|
| 43:02 | we didn't have that reaction and there just, there was just glucose here |
|
| 43:06 | glucose there and you had 10 molecules glucose out here, they'd keep flowing |
|
| 43:12 | until when keep she was like five and five, then it, |
|
| 43:20 | there's no more movement. OK? because we, we are converting that |
|
| 43:26 | , we are converting it to then this is van vanishingly small, |
|
| 43:32 | ? And so it just keeps coming coming in, keeps coming in, |
|
| 43:35 | in. OK. Uh Same as is the exact same thing, different |
|
| 43:40 | and it gets converted here to So they diffuse dependent on each other |
|
| 43:45 | it can keep coming in until of , you know, the glucose does |
|
| 43:49 | inside then that will stop it. if it's not, then it keeps |
|
| 43:54 | . Um it's very common in bacteria transport sugars this way. Um ABC |
|
| 44:01 | are a little more specific in terms having a molecule that binds to the |
|
| 44:06 | , OK, binding into a transporter in. This is uh this of |
|
| 44:15 | , is a active process by the of A TPS being, being |
|
| 44:20 | So in bring things like uh many acids follow this process of bringing them |
|
| 44:27 | um that not necessarily coo specific. think there's probably other members as well |
|
| 44:35 | do this but very common. And then the membrane, permanent weak |
|
| 44:40 | base. So this is all based your, your call from chemistry, |
|
| 44:44 | old uh uh conjugate acid base OK. So here uh here we |
|
| 44:53 | a a weak acid. So remember contrast to something like cl hydrochloric |
|
| 44:57 | it all it all dissolves to um and chloride ions, right? So |
|
| 45:07 | you were to have a test right? And you drop HCL, |
|
| 45:12 | you'd see are these OK? This beyond nature of a strong acid, |
|
| 45:19 | concept for a strong base. But with these uh weak acid |
|
| 45:26 | OK? You will have, for , up here, all, all |
|
| 45:32 | of these species are present. So key here is the um the uh |
|
| 45:40 | there is this form, here is , the H A, right? |
|
| 45:47 | neutral. And so that's they're only small molecule and you can it through |
|
| 45:52 | membrane, OK? And when they inside the cells, when they can |
|
| 45:56 | an issue, right? Because you it, it only partially dissociates, |
|
| 46:00 | , that's the thing. And so does. So and that acidity occurs |
|
| 46:05 | the cell P drops, you of course, that can be stressed |
|
| 46:10 | the cell it's gonna have to neutralize it generally um what they do |
|
| 46:16 | they, they use amino acids that in the cell. These act as |
|
| 46:20 | and amino acids have both properties of acid and base. And they can |
|
| 46:24 | of help to neutralize the effect of increasing acidity or it's becoming more basic |
|
| 46:30 | the same thing can happen with a base like you see over here. |
|
| 46:35 | . So um you know, just the things that micros have to |
|
| 46:40 | with. Um you know, these of these kinds of compounds are what |
|
| 46:46 | see often as preservatives of food. something like citric acid is a very |
|
| 46:51 | preservative and it has the properties of , of a weak acid. And |
|
| 46:56 | you see it in bread and other and, and, and it's there |
|
| 47:00 | preserve it to keep microbes from growing it does it by this, this |
|
| 47:04 | here. OK? Because this is be a gross inhibitory effect on the |
|
| 47:11 | that's undergoing this and it's gonna keep from growing unless it can really counteract |
|
| 47:16 | . And that's many, many food have this effect. OK. Um |
|
| 47:22 | questions about these transport, transport things . OK. All right. |
|
| 47:29 | uh so now the next several minutes on the cell wall. OK. |
|
| 47:38 | Next questions rather. So gram gram negative. So why should you |
|
| 47:42 | about that? Um Graham stain was 120 something years ago. OK. |
|
| 47:53 | is done to this day. It's um you know, you're in |
|
| 47:59 | lab doing work like this, identifying . What have you um you may |
|
| 48:06 | have all this, all the bells whistles, other labs have in terms |
|
| 48:09 | technology and you know S DNA and . Graham is still valent. |
|
| 48:15 | it's a way to really differentiate group root bacteria. OK? It can |
|
| 48:22 | a first step in identification. And so it, they can have |
|
| 48:28 | implications as well depending on where you're a sample from. If you get |
|
| 48:33 | sample of your uh cerebrospinal fluid, . Which is the fluid that bathes |
|
| 48:40 | brain and spinal cord. And you under the microscope, you do gram |
|
| 48:44 | and you see gram negative gram negative that are paired like this called diplo |
|
| 48:54 | and they're floating around in your spinal and the gram negative. That's pretty |
|
| 48:58 | telling you you have the meningitis OK? If you get the same |
|
| 49:03 | from a uh throat throat swab and gram po positive cox chain, so |
|
| 49:11 | strep throat, OK? It's not definitive, but it's certainly presumptively indicates |
|
| 49:18 | right. So there has diagnostic value well. OK. So um and |
|
| 49:24 | I only put this in here because may see this, you know many |
|
| 49:29 | you are taking like these mcats and , right? And I've seen references |
|
| 49:34 | fermi cuts and proo bacteria. So these are the two groups, you |
|
| 49:40 | , positive negative they're big, they're taxonomic groups. And so they differentiate |
|
| 49:46 | based on the nature of the cell in time. So uh OK. |
|
| 49:54 | let's look at some questions here. right, this all relates to the |
|
| 49:58 | wall, so wall structure. So two types of bacterial cell envelopes |
|
| 50:06 | shown. What is the structure A? OK. So this one |
|
| 50:25 | one, identify the gram type. . How a native and then |
|
| 50:41 | Mhm China. OK. I take breather at five seconds. The next |
|
| 51:15 | one and the next four or five have the same picture. OK. |
|
| 51:25 | , all right. All right. ce E is E is five. |
|
| 51:40 | that's right. LP S layer. thinking about that myself. So |
|
| 51:44 | that is LP S layer, So that's the same slide. |
|
| 51:52 | See I would change G now it's there's G there's G OK. |
|
| 52:00 | OK. I can answer. So G is the little black snake |
|
| 52:16 | looking thing A on six. Counting down. Yeah. Uh BB |
|
| 53:12 | two is correct. That's right. right. Um What's the least |
|
| 53:22 | two types? Which label represents lipoprotein protein? Mhm. Oh OK. |
|
| 54:17 | . Come down 5432 one. It's . Yeah. Yeah, it's, |
|
| 54:33 | , you know uh one more are ever gonna end? Ah OK. |
|
| 54:43 | next 30 slides are gonna be each picture, same picture check. |
|
| 54:55 | I think you get the point of slides, right? You gotta know |
|
| 54:58 | different parts of the cell wall, ? So cell envelope. OK. |
|
| 55:27 | yeah. OK. Let's count down three that yeah, two of the |
|
| 55:59 | . Let's see. And I, I assume theoric acids in this |
|
| 56:11 | All right. That's the cell wall . So here, here, so |
|
| 56:18 | is peppered. The glide can And that's what contains, there's two |
|
| 56:23 | but one of them is an aic . OK. Um OK. So |
|
| 56:31 | is a particular question. OK. um just listing the various components to |
|
| 56:38 | familiar with really? OK. Um I handed this to you, could |
|
| 56:43 | fill out all the letters here? ? So I think I actually do |
|
| 56:48 | here. OK. So o Energen hard to li a poly. So |
|
| 56:57 | negatives very positive as you obviously figured negative positive. The give away of |
|
| 57:10 | , there are several, the 11 the main ones being the appearance of |
|
| 57:13 | outer membrane. So there's two membrane in a gram negative. OK. |
|
| 57:18 | Both of course have a, the , this is so now because we |
|
| 57:21 | an outer membrane and a gram we use the term inner membrane to |
|
| 57:27 | here. But essentially it's the equivalent what the gram positive have has we |
|
| 57:32 | call it the inner membrane because there's one there. OK. So E |
|
| 57:36 | C are equivalent. OK. Um uh so of course, with the |
|
| 57:42 | negative, you have the little polysaccharide here. You don't have these tyco |
|
| 57:48 | , so little dark things here If you will those help to reinforce |
|
| 57:53 | pepto glycan, there's so much of in the gram positive, you need |
|
| 57:57 | extra reinforcement. OK? Uh Because have an outer membrane, you now |
|
| 58:04 | a space, this what we call paras space in the gram negative. |
|
| 58:08 | . The endotoxin that's part of the material. OK? You, you |
|
| 58:14 | mentioned that cross bridges. Um it's that obvious here, but certainly in |
|
| 58:21 | gram positive you're gonna have it. what kind of helps link along with |
|
| 58:26 | Coke acids. The cross bridges are links within the petrol. I can |
|
| 58:33 | gram negatives have that. Uh although may not be the is not that |
|
| 58:37 | here, but you can have overlap this chain here that can create the |
|
| 58:45 | bridging. So you're not gonna have much in a gram negative but you |
|
| 58:48 | have some but certainly a lot in gram positive, right? Uh Pepto |
|
| 58:53 | kind of course is is the purple lipid A is only in the um |
|
| 58:59 | negative lipid A is what creates the effect. OK. Then of |
|
| 59:08 | the the two building blocks of the like are right here. And then |
|
| 59:13 | protein is what connects the anagram negative is what connects the cell wall material |
|
| 59:19 | the uh outer membrane. OK. um OK. So let's look at |
|
| 59:26 | real quick here, basics of the wall, as just mentioned in these |
|
| 59:32 | , right? So we've got a repeating, so kind of analogous to |
|
| 59:38 | DNA right in the sugar phosphate so to speak, kind of a |
|
| 59:42 | structure in terms of repeating repeating sugar , uh the glucosamine and aic |
|
| 59:50 | And so it's the mic acid residues where the cross bridging occurs. |
|
| 59:57 | Um The uh the strand basically forms , this would be what surrounds a |
|
| 60:05 | shaped cell, for example. Like so and basically it wraps around |
|
| 60:10 | like a, a basket, they it, call it a sacculus. |
|
| 60:15 | it can be of course several layers . Uh it helps to maintain |
|
| 60:18 | So cells tend to be slightly hypertonic comes in, think of, think |
|
| 60:23 | a balloon, a balloon in a box and the cardboard box is a |
|
| 60:27 | wall, fill the balloon up with . It's gonna press against the side |
|
| 60:31 | help maintain integrity. So it's kind goes hand in hand and kind of |
|
| 60:36 | maintain the shape of the cell. . That the uh osmotic pressure plus |
|
| 60:41 | cell wall. OK. Um the uh other thing was um I'll |
|
| 60:53 | of it in a second. Um OK. So here kind of |
|
| 60:57 | close up of how these connections are . Um And so because of |
|
| 61:05 | cell wall synthesis is a uniquely procaryote and of course, is a target |
|
| 61:12 | antibiotics, right? There's several enzymes in bringing this about both synthesis and |
|
| 61:19 | bridging, et cetera. And these all targets for different antibiotics. |
|
| 61:24 | Penicillin, we know of uh ampicillin. These are all target different |
|
| 61:30 | of cell wall synthesis. OK. so uh a man called my, |
|
| 61:36 | . So here's the connection that And so uh this is a very |
|
| 61:42 | peptide sequence is the gluten acid. don't need to memorize these. Uh |
|
| 61:48 | it can vary, it can vary from bacterial species to species. Um |
|
| 61:54 | when you make the connection, it's this unique amino acid here called amino |
|
| 62:06 | . OK. And so it connects an alanine. So you see that |
|
| 62:12 | , there's two terminal aines, one when the connection is made. |
|
| 62:17 | Um And so the effect of penicillin course targets enzymes that synthesize solo material |
|
| 62:26 | uh does as well. And so actually will bind it, bind |
|
| 62:33 | OK. This is a Myerson, will bind here. And so preventing |
|
| 62:40 | cross bridge from forming. OK. What happens is remember there's a cytoplasmic |
|
| 62:48 | underneath this, right? And you interfering with so a synthesis not making |
|
| 62:55 | bridges, then that cell membrane underneath to kind of come through these where |
|
| 63:06 | connections are broken, the membrane kind comes through and, and vices |
|
| 63:12 | And so the cell dies, So um very important to maintain the |
|
| 63:18 | of that, of that cell wall . Um And so, of |
|
| 63:23 | we're aware of resistant types. So can have bacteria that will um basically |
|
| 63:31 | the penicillin. These are what beta mass do. Um Vaicin resistance comes |
|
| 63:36 | through um altering, basically altering the terminal Alay. So if they have |
|
| 63:45 | mutation that occurs, that changes this acid to maybe something like lactic acid |
|
| 63:55 | one change. OK. And we that in fermentation that now Vankin does |
|
| 64:02 | recognize it, OK? Because it's for recognizing Alay, right? But |
|
| 64:08 | it sees this right and can't So essentially now it's resistant to bank |
|
| 64:15 | because you don't get the effect OK. So um anyway, so |
|
| 64:21 | different types of resistance. And so uh um so side by side, |
|
| 64:28 | can see the contrast between these 2 positive gram negative. The um um |
|
| 64:35 | , the cell membrane in both. then as you go beyond, you |
|
| 64:39 | the differences, right? Petrola can thin layer, uh very thick and |
|
| 64:43 | gram positive. We take co acids in a gram positive to keep um |
|
| 64:48 | integrity. I'm sorry, cell wall . The um li of proteins connect |
|
| 64:55 | cell wall to the outer membrane to it in, in place. Uh |
|
| 65:00 | space here but not seen in a positive uh the outer membrane like completely |
|
| 65:07 | in a grand positive. OK. And lots of lipid material out here |
|
| 65:14 | S layer OK. That is really you're doing the grand stain this |
|
| 65:20 | That's really what the difference comes down is you stain both cells with a |
|
| 65:27 | violet, makes everybody purple. You then uh then iodine helps to |
|
| 65:33 | that, that uh mean keeping that violet color. But then you add |
|
| 65:38 | decolorize agent right? 95% ethanol, dissolves membrane material. So the ethanol |
|
| 65:44 | essentially just kind of dissolves all of . And the stain comes out, |
|
| 65:50 | ? It doesn't happen in the gram . You don't have that lipid |
|
| 65:54 | So uh you have to. So order to see a gram negative |
|
| 65:58 | you gotta add color to it. for whatever reason, saffron is called |
|
| 66:03 | . So gram positive purple, gram is pink. OK? So um |
|
| 66:11 | uh the LP S layer and the effect, we'll talk about that later |
|
| 66:16 | the semester uh in the context of . Um but um all gram negatives |
|
| 66:23 | have endotoxin that can produce an OK? Obviously, it's a main |
|
| 66:29 | with pathogen types. OK. And when we look at the LP S |
|
| 66:35 | , there is um I go for sec there is you can see a |
|
| 66:43 | , it is in both sides. you have this inner side and the |
|
| 66:49 | side of the outer membrane, you see you have different molecules on this |
|
| 66:53 | compared to here. OK? And LP S molecules OK. Have with |
|
| 67:01 | . This material here, OK. lipid A material. So here is |
|
| 67:07 | we call the old polysaccharide. This antigenic activity. You can interact with |
|
| 67:14 | , right? Immuno immunogenic activity. The oh polysaccharide Ogen we talked |
|
| 67:25 | oh, we haven't yet. We'll about that soon. The Ho One |
|
| 67:28 | Engine. So my favorite E right? The Chipotle E Coli |
|
| 67:35 | OK. The O comes for the A. So this was developed decades |
|
| 67:42 | as a way to identify medically important of E coli and salmonella and similar |
|
| 67:51 | due to their LP S layer. we have uh antibodies basically to the |
|
| 67:58 | types of O and H and And so it allows us to quickly |
|
| 68:02 | and there's a food blown outbreak and suspect E coli uh we can take |
|
| 68:07 | sample, add antibodies for the various H engines and identify it very |
|
| 68:14 | And so the 0157, that's O number 157. OK. So it's |
|
| 68:21 | for the H antigen as well. . And so the endotoxin effect comes |
|
| 68:27 | when the cells die and then you this material is released when the cells |
|
| 68:34 | . OK. This acts on immune cells in your body. So your |
|
| 68:44 | , your immune system cells see this react to it. OK? And |
|
| 68:49 | we'll learn later, the response is production of different what we call |
|
| 68:54 | different chemicals that tell your cells what do. Ok. And if it's |
|
| 68:59 | local response, we're built for Right? Because that's what it's made |
|
| 69:04 | . You. You have an infection a certain part of your body. |
|
| 69:07 | effect occurs to help deal with But if you're not, if |
|
| 69:11 | if it's a condition where you're, bacteria are throughout your body, we |
|
| 69:15 | septicaemia or in your bloodstream. potentially all of your immune system cells |
|
| 69:22 | react to it. And when it's body wide reaction, systemic reaction, |
|
| 69:28 | overwhelms the body too much and we handle it. We go into shock |
|
| 69:32 | , right? That's essentially what the effect is. It's overwhelming the body's |
|
| 69:37 | system. Of course, the, gram negative pathogen causing this, the |
|
| 69:44 | effects occur with this. If it's into your bloodstream, ok? If |
|
| 69:50 | advanced that far, if it's still a localized infection, you generally can |
|
| 69:55 | that. But if it gets more , then you may have issues. |
|
| 69:59 | . That's, that's when fatalities can . So with a gram negative |
|
| 70:05 | you can't fool around with it for reason, right? Um You don't |
|
| 70:10 | , don't let it advance to being getting into your blood. Ok. |
|
| 70:15 | again, we'll elaborate on that later the semester. But the um other |
|
| 70:21 | here is, you know, don't also think of a cell |
|
| 70:26 | especially in the grand positive. That a lot of the material and it's |
|
| 70:29 | a brick wall, it's actually very flexible, it's porous, |
|
| 70:34 | it's not very restrictive stuff. stuff can get in there fairly |
|
| 70:38 | but you have the membrane to kind restrict what can come in, |
|
| 70:42 | So the cell wall is not, , is not super rigid, there's |
|
| 70:47 | , it's porous OK. The S is seen in both both gram mega |
|
| 70:52 | gram positive actually. OK. Think that as kind of a a net |
|
| 70:58 | like covering of the cell. It has protein structures in there like |
|
| 71:04 | see a range like this. Not a lot is known about it |
|
| 71:10 | cells lose it while they're growing OK. If you have a a |
|
| 71:15 | in the lab on a plate, example, bacteria can kind of lose |
|
| 71:20 | lot of their features. And s is one of those uh motility is |
|
| 71:25 | , a multi organism can lose its its flagellum because typically in a |
|
| 71:31 | you're growing that thing up, you , under super nutri, under super |
|
| 71:37 | conditions, right? Doesn't have to around to find food because you're growing |
|
| 71:41 | in, you know, really rich . And then those con con conditions |
|
| 71:45 | the cell will lose it on because expend the energy to move it? |
|
| 71:49 | I don't need to move, I'm fed this buffet of food, |
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| 71:53 | Very common for Australians in the lab kind of lose some of these features |
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| 71:56 | that reason. And s layer is of those two we can lose |
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| 72:00 | after a while. But nonetheless, kind of a covering, it's very |
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| 72:06 | . Uh but there is some evidence shows it, it, it can |
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| 72:10 | in, in adhesion in some maybe a protective kind of coating for |
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| 72:15 | but, but that's kind of here there nothing you know that, that |
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| 72:20 | , these features are common to all of bacteria. But here and there |
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| 72:24 | seen evidence of that. OK? again, we see it both in |
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| 72:27 | positives and gram negatives. OK? That's, that's a good place to |
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| 72:33 | folks. So remember none of this we're talking about today is on exam |
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| 72:38 | . All right. So it's all next, next exam. OK? |
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| 5999:59 | |
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