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BIOL 2321_Microbiology for Science Majors - 2321_MW4_3_9_23_Lecture
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00:03 Yeah. Ok. Hey folks. welcome. Let me get this thing
00:26 . Testing. Ok. Uh Let's . All right. So um today
00:36 gonna finish uh 14 which ends Unit . OK. So um back from
00:44 next week, um we'll start the unit. Of course, none of
00:50 is on uh exam two. Of , it's on the next exam three
00:54 is in April of mid April. Anyway, so uh we come back
01:00 we've got uh at the end of week of that we uh too.
01:07 . So, uh remember that the right? That's gonna cover six and
01:13 and 14 that we've been covering and go through tomorrow, but you'll have
01:18 until 20. So you basically have days to complete that and uh then
01:27 workers do the, the same, same Monday. So uh lots of
01:32 between now and then. Ok. So what we gonna do is we
01:41 basically three things to cover in photography um I wanna uh then end kind
01:48 with uh just based on some uh , some people come by and they've
01:53 about this about the reduction potential So understandably I get that. That's
02:00 you look at that and go, , I still don't get it.
02:02 fine. So I wanted to spend little bit of time on that,
02:06 , of, um, other questions away. So, but,
02:12 I think it's important thing to understand terms of the concept of it.
02:17 we'll spend a few minutes on it we have a question. I kind
02:21 frame it around that. OK. , but let's uh first start with
02:27 what we usually do, which is recap. OK. So, um
02:35 . So again, in context so we started this metabolism section with
02:42 metabolism, right? Chapter 13. how hetero eat basically, right?
02:49 And what and how, how uh gets energy from that, right?
02:53 mean fermentation uh you can, you start with glycolysis, right?
02:57 then then you can either go through or respiration, right? Which is
03:02 the stages of pyro that you look and um cycle. Then we we're
03:10 up energy molecules along the way, ? And the h primarily uh fa
03:16 two in the crab cycle, um couple a couple of spots to pick
03:21 A T P S now by that level phosphor, right? And
03:26 but then we're gonna take these, these electron carriers, of course,
03:30 to electron transport chain, right. we're oxidizing the source, right?
03:37 that source is providing the electrons for red reduced carriers, right, the
03:42 A DH, right? And they up going to the um electron transport
03:49 and then that would kind of delve that in, in the respiration section
03:53 time and time before uh the components this up, right. And uh
03:59 energy from that um uh it's a negative delta G process and the energy
04:05 used upon protons, right? And that stored energy is then used uh
04:12 make a T P S right energy as they go down the gradient,
04:16 talked about this, right. uh but in restoration, so we
04:20 at a restoration last time, So that of course, depends on
04:24 going on there, right? It's other than that, right? And
04:29 uh we looked at uh Lio Hydrogen Trophy method. So these are
04:36 of related, of course. And um Hydrogen Trophy is kind of that
04:44 metabolic energy producer, right? The two oxidize that uh protons and
04:51 And so that's used among not just but he like E Cola can do
04:57 . Um And then uh of li relate to what is the nature
05:02 the sources inorganic, right? Um genesis is a property only of a
05:10 of Archaea. OK, making methane CO2 and uh hydrogen right there.
05:18 so um then as similar to dissimulator . And so I should mention
05:23 you know, in the context of restoration, right? With the n
05:28 and sulfur compounds right here. But they have diff can have different
05:34 , right? Depends on the oxidation of the molecule, right. It's
05:40 oxidized, that tends to be the that becomes an acceptor and is
05:45 right? So they have different roles that role is kind of defined right
05:51 . OK. So you can have molecules that serve better as a terminal
05:57 , right? For anaerobic respiration, can serve as a source for Liro
06:03 . So you can be either here here depending on the nature of your
06:09 oxidized you are. OK. And similarly with sulfur compounds, right?
06:16 those can be used for restoration that more oxidized, these forms and more
06:22 forms service energy sources. So where fit, right? Depends on kind
06:26 their what they're best suited for. . Chemically. And then finally,
06:33 assim toy disc simulator processes, So remember that assimilation is once something's
06:39 , does the cell hang on to or does it become part of its
06:44 part of its biomass? Right? it is, that's in a simulator
06:47 or pathway, right? This simulator released. Uh But then it's it's
06:53 to be used by others in the . OK. So I hope that
06:57 of recaps everything. Uh But we then talk about uh a little bit
07:03 photography. OK. So uh now concepts, we talked about in
07:11 the context of respiration, this right? It doesn't, it changes
07:18 in kind of the components evolved in . But the idea and the process
07:23 holds true in phototropic, OK. just that light is a driving force
07:28 . OK. Obviously, hence photo . So, um so of
07:33 I'll anyone that's a photo trope, all have some things in common.
07:39 course, if you're absorbing light, gonna have molecules that are made to
07:43 that, right? So they're gonna chlorophyll based, non chloral based,
07:48 you're gonna have some kind of light molecules, right? And these are
07:51 be and the membrane is gonna be part of it as well because you're
07:55 stuff the membrane full of the Um The membrane also serve the purpose
07:59 being able to create that gradient right? Because we're all gonna generate
08:03 proton gradient as a result of this then um taking it and converting energy
08:10 light energy into energy molecules, A T P and A B P
08:16 . OK. Um So that's gonna common to uh photo but may not
08:24 be common. Is this one right ? OK. The photos reaction.
08:29 uh most all those of the four processes all just like this diagram
08:36 They need a source. OK. source water served the purpose for
08:43 algae santi bacteria. OK. Um molecules serve that purpose for other photos
08:52 . But there is one process that started with that doesn't use this for
09:01 kind of photo trophy. OK. , well, so we'll begin that
09:06 a question to kind of cover OK. So which is true?
09:10 this is the bacteria or adoption based . That's the, that's the unique
09:16 if you will. OK. It involve any kind of chlorophyll molecules.
09:20 me move this here, open OK. So which one of these
09:26 true with respect to that? All , let's count down here.
10:39 21. OK. So um so remember you but your adoption based
10:49 right? It's going to uh that's system that doesn't need uh an electron
10:54 . It's a absorption of photons strictly it is and they have that unique
11:00 protein and retinol combination, the retinol light and because it's covalent bound to
11:07 protein, it, it absorbs light changes in terms of its configuration and
11:14 change changes the protein configuration, which enables it to pump protons out.
11:20 it's basically a light driven proton OK. And so um The uh
11:29 statement here is this one. So they um are photo heros,
11:36 ? They don't fix C O OK. So they absorb um green
11:41 , they absorb green light and as result of pure purpleish color,
11:48 Um And so that eliminates these two correct choices. OK? Um Doesn't
11:54 ation of a donor again, just of photons of light is what
11:59 what uh how the system works and doesn't use less chlorophyll, of
12:04 uses lies Bater adoption. Ok. , she is the only one
12:08 So, um so, but we'll about the rest of the time on
12:12 chlorophyll based systems. OK. um and so in looking at
12:20 of course, I'm assuming your what you're exposed to most is
12:27 is the oxygen photosynthesis the way plants algae side bacteria photosynthesize. OK.
12:37 you can really boil it down to types we're looking at today into if
12:42 recall oxygen photosynthesis, right? Has photos, right? One is associated
12:49 A T P production, one with A B P H production.
12:55 So uh all plants algae santa bacteria photosynthesize do with that they have both
13:03 . OK. The other types which only found in bacteria, not in
13:11 , not in plan. Uh certain of bacteria can, can photosynthesize by
13:19 only one of those two. They're not combined, they only have either
13:25 one or two and that's it. that's basically the separation of the three
13:29 . Is that OK? Then of , the, the fourth one is
13:33 bacterial adoption group that we talk about . OK. Which is completely
13:37 OK. So, so that's what look at that in a little bit
13:41 detail as we go through, but in a nutshell. That's those are
13:44 three differences in terms of the chlorophyll . OK. So, of
13:48 uh the oxygen photosynthesis is what you um is in terms of amount of
13:57 activity is probably likely the greatest, know, it uh utilizes a lot
14:01 obviously co2 um planet on earth and atmosphere fixes. Uh And that's what
14:07 of the energy is going to. , that uh the light reactions that
14:11 called are going to fix CO2. ? Because they're auto um there are
14:18 couple of exceptions. Uh We already one bacteria adoption based, they're photo
14:23 , there's another group in here that's a photo Hetro in China. But
14:28 . So with oxygen and photosynthesis, the um uh based on chloral,
14:35 chlorophyll lighting pigments. And so remember this group really is the foundation for
14:43 ecosystems for the terrestrial plants, aquatic , cyanobacteria, um algae. Um
14:54 , they're the foundation, they'll be highest biomass, right? Producers,
14:59 ? Then you'll have successive layers of uh consumers on, on top of
15:03 . But unless they're mouth for the kind of shape, OK.
15:07 uh of course, they're critical to on this planet. And so uh
15:13 chlorophyll base uh being these things are membrane bound molecules, they're gonna have
15:19 area that's a very nonpolar part of molecule mean to stick to a
15:25 OK. The part here is what the light right, what they call
15:31 chroma. OK. And so uh chromeos are not just um part of
15:40 fields. I mean, uh if in lab, the stains you use
15:43 saffron and crystal violet and these their chroma have chroma forces as
15:48 that's why they have these really bright . Um And so the um the
15:57 types, there's two, a couple types A and B, they differ
16:00 slightly. Um but regardless the arrangement these components, so you've got a
16:07 of proteins, chlorophyll molecules and you other pigment molecules like xanthophyll carotenoids and
16:18 . And they kind of helped to broaden the wavelengths of light they can
16:24 . OK. And so that's really it's all about is maximizing light
16:29 OK. And that is all dependent on uh the types of pi of
16:34 you have the orientation of those molecules to light. OK. And uh
16:42 that's absorbed, it's not absorbed the way every time, right? Because
16:47 molecules will be slightly different in orientation whatnot. So, you know,
16:51 the ones that first pick up light be here or maybe here or what
16:55 you. But once that happens, they uh those photons of light that
17:00 is transferred among these what we call complexes. They're the ones receiving
17:06 the photons of light. And then that the that energy is shuttled to
17:13 the middle, which is a reaction here. OK. And as energy
17:20 , is transferred from component to there's, there's it becomes less and
17:25 energetic. But that that pair in middle, those chlorophylls in the
17:29 OK are maximized for absorbing that light . And then using that to
17:36 push pro electrons out. So essentially molecule, this is what we call
17:42 in this entirety. That's a photo , right P S, they call
17:47 P S one P S two, that's a photo system. OK.
17:50 so the light energy is meant to out electron from the system. And
17:56 it goes through, we'll see this , but it goes through a series
17:59 um electron transfer proteins. OK. that's how this begins. OK.
18:05 so the the photo systems in the losing electrons is becoming oxidized.
18:12 And so then you have to, of that you need to replenish,
18:16 ? Just like we have to replenish aspiration, you have to keep feeding
18:20 , you have the same thing right? And so for oxygen
18:25 it's water, right? H2O is donor of electrons to the system.
18:31 . So uh now, in terms how this is structured in the
18:36 OK. So you're obviously aware of cods, but your familiarity is likely
18:42 the context of a chloroplast. So you kind of have to uh
18:47 it out of your head because that bacteria don't have co OK. But
18:53 do have membrane and that membrane can highly folded up, which is what
18:58 seeing here. OK. And and, and it just really represents
19:03 plans of membrane that's highly convoluted has little connections between parts of the membrane
19:10 kind of keep it all all OK? But lots of surface
19:15 right? That's stuff full of pigments to have barrier, right, to
19:18 the, the proton radium. but they it's called the thyroid,
19:23 ? That's it's stuffed with these pigment , OK? Have them too,
19:29 ? But they're just contained within an within the cell. This is not
19:34 here. This is a bacterial cell has this just really folded membrane structure
19:40 of these pigments. OK? so looking at absorption of light,
19:46 , that's what it's all about. so chlorophylls absorb in the red and
19:51 range. And so I have peaks you see here. OK. Uh
19:56 then you know, it's, it go a little bit beyond that because
19:59 see there's kind of a a right? And that's due to the
20:03 accessory pigments that are part of the along with chlorophyll, OK? And
20:08 this is what your oxygen types will . OK. So red and absorbing
20:14 and blue means you reflect green So hence they look green. So
20:19 plants, santa, bacteria of are pretty much green and so bacterial
20:25 have peaks outside this especially over So remember light wavelength, the energy
20:32 it is proportional to the length So long wavelengths means less energy,
20:40 wavelengths, more energy. OK. clearly what bacterial chlorophylls absorb is rather
20:47 energy that's like infrared, far infrared OK. And um so the uh
20:57 terms of hierarchy, if you have mixture of these which you do in
21:01 say a aquatic environment, your oxygen , particularly at the top parts,
21:07 tier um absorbing is more high energy . OK. Then this light as
21:14 gets absorbed, then this light trickles this lower energy light and cashes down
21:22 the lower layers are where the types that light are at. OK.
21:26 kind of in the middle of the , right? And they can be
21:31 the sediments, even certain types of this light, really low energy tend
21:35 be kind of in the sediments or in the lower depths. OK.
21:40 But you know that's, that's the they absorb and that's how they can
21:44 their energy. OK. So when look at um uh the, you
21:51 heard it called disease scheme uh but oxygen and photosynthesis. So starting with
21:57 of the flow of electrons who are from water to the photos systemss to
22:03 OK. And so again, they've the two systems together, right?
22:08 all the photosynthesizes that do it this have the two photos systems together.
22:13 and, and two comes first because was discovered first, but it's actually
22:20 in the order. OK. So kind of why it doesn't like
22:23 you know, descending order here. regardless, so we have light
22:27 electrons knocks them out and then you like in respiration, right? A
22:32 of cytochrome quinones or the things that up the respiration transport chain, same
22:39 here. OK. Different molecules but functions. OK. So electron transfers
22:46 to a negative delta. That's a to be a delta sign. Let
22:50 try it again. OK. Uh uh delta G. OK. Not
22:58 better. OK. So they built G proton motor force, right?
23:03 so we pump protons out and then have an A T P A over
23:07 . OK? And uh A T synthe and so the protons will come
23:12 . This is the same thing we've before, right? In the process
23:17 T P is made, OK? protons come back in the same exact
23:22 , right? Osmosis, all that's same poll is gonna be a little
23:26 different. All the A T P is not gonna be that much
23:29 OK? But that result is making . OK? And that's, and
23:35 is only part of photos systems OK? It's important to kind of
23:41 that because when we talk about the types of tropes, they're only either
23:44 have just one or the other. if they have PS two, then
23:47 gonna have all that. OK. , so then of course, the
23:54 uh from where they begin here to here Lost energy, right?
24:02 but they, that's what feeds photos one. OK. Right here.
24:09 . Let me erase some of this of the way. A little
24:12 OK. So here is our um system uh here and so electrons are
24:23 then feed that from photos systems two again, light abortion, they get
24:29 again. And here's another uh chain electron carriers, but we're not forming
24:35 gradient again, like they're just going N AD P which is reduced to
24:40 AD P. OK. So um not a, there's not a similar
24:45 T P proton pump mechanism associated with part and P S one but there
24:51 the N AD P H production. this is was associated with P S
24:56 . OK. So, um so , light driven oxidation, right?
25:03 electron like that has become oxidized. we gotta, we gotta fuel
25:07 we gotta keep adding electrons to And that's where water comes in.
25:11 flus, water become oxidized, giving electrons and forming 02. Hence the
25:20 oxygen. OK. So uh so so electron flow Or the energy I
25:27 say that comes as a result of light dependent reactions right goes to in
25:35 part to fix co2 that takes a of energy, right? Remember we're
25:40 that to build things like C six 12 06. So that's a big
25:46 . OK. So um that takes lot of energy to do that.
25:52 . And that comes from what you from the light reactions. OK.
25:57 that's oxygen photosynthesis, plants, algae bacteria. OK. Um So water
26:05 oxidized. Uh Oxygen is simply just product of the oxidation. OK?
26:10 is not being reduced or oxidized. just a product of the water
26:14 OK? Um So uh now, we look at the other two
26:21 OK. And again, here is flow. OK. Right here.
26:31 in this fashion here. So here go. Um any questions about
26:39 I guess you probably heard this a times already um in bio and before
26:44 um but the next part is really bacteria that have bacterial photos that have
26:51 P S two or P S And then, and the things that
26:53 associated with it. The first Uh I did it this morning.
26:57 , I forgot I had this picture here again, just showing you kind
27:02 an actual membrane and the components. . You don't need to memorize things
27:07 and uh cytochrome B F, don't about that. Uh But it's very
27:13 to what you see in respiration, ? Cytochrome quino molecules transferring of electrons
27:20 the photos reaction providing those electrons um hitting. Uh But then of
27:28 formation of proton radiant right here is A T P ase here. So
27:33 energy production that we saw in respiration similar. OK. Um And so
27:39 the middle, there's A P here's the P S one.
27:43 And again, associated with N AD H production. So, uh the
27:49 energy uh that result of oxygen of course, N AD P A
27:57 um uh OK. So let's look these other two. So the first
28:03 is, so both of these processes up now are an oxygen oxy is
28:10 produced, it's not produced because a to the system, when those are
28:16 , they don't form oxygen. So that, that's what we call
28:19 an oxygen. So they use something than water. OK. And the
28:24 sulfur bacteria typically use hydrogen sulfide but can use things like hydrogen in some
28:32 , iron kind of a species specific . Um but they absorb, you
28:38 , relatively low wavelength. So 8 compared to what we just saw like
28:42 the seven hundreds. OK. Um they use sources again, that is
28:48 other than water. OK. Light , same concept here. Uh electron
28:54 kicked out and then a series of carriers finally to make an A DH
29:00 an AD P H, it kind varies sometimes. Um But uh if
29:06 look at it on the right so this, it's not an
29:11 OK. But it is a struct structure you find in these types.
29:16 It doesn't have the lipid bilayer that organelle would have. OK. It
29:22 have fossil lipids. OK. You're arranged in that bilayer form. It
29:26 have proteins here. OK. Uh what it does have is packed full
29:31 these bacterial chloro molecules. That's what green blobs are. OK. So
29:36 a light absorbing factory basically. So absorbing light, OK. And
29:44 uh electrons being kicked out. And um then resupplied by the
29:52 which is example is H two S . So now being a type that
29:59 the P S one system, it have the, the system linked to
30:05 T P production, but obviously, can still make A T P S
30:09 . It can create a proton So you see the products of the
30:15 here. So here's protons here, ? So it can produce a proton
30:19 by simply oxidizing the donor molecule And then it will have an A
30:24 P A associated with it. And It, it will certainly produce ATP
30:29 way. It's just not part of , of a PS two system.
30:33 . Um the other thing here is they are auto trust, OK.
30:38 do fix co2. uh the the last group we're gonna look at
30:43 has the PS two system, their header tropes which I um And so
30:50 really what, what, what this is. So the next one is
30:54 one that has just photos systems but also is an oxygen.
31:01 Um Now, this is a little unique in that. Um it's a
31:07 low energy, OK, like far , which is really low and that
31:14 a consequence to that. OK. what it means is it's such low
31:20 absorbed it, it doesn't have enough really grab electrons from something else like
31:26 photos reaction as everything we've seen uh the chlorophyll based group half.
31:32 So what do they do? they absorb light, they do uh
31:38 the electron out, right? But it recycles back. So it's a
31:44 kind of process. OK. And , because it's such a low energy
31:50 by this photo systems that not uh it's not a powerful enough oxidizing
31:56 to grab electrons from something else. it just keeps recycling. OK.
32:00 we call it cyclic photo correlation. . And so it does, you
32:07 , because it's P S two, has the A T P A s
32:10 the ability to form a T P . But it relies on being a
32:16 to provide its carbon to uh produce like an A DH. OK.
32:24 Again, really, because of the they absorb is so little energy but
32:28 enough to be just A P S it still is a heterotrophic. So
32:31 the operative term here. So whenever see header troph, regardless of what's
32:37 front of it, right, in case, photo, It cannot fix
32:42 , it's gonna do what he which we saw in, in previously
32:47 metabolism. That's what it's gonna but it has its ability to,
32:51 do this as well. So, know, somewhat a very kind of
32:55 organism in a way. OK. And this is the type you find
33:00 the, in the sediments, sediments aquatic areas, we land environments um
33:06 kind of where they live because they is where you get the low energy
33:09 absorption time. So if you're gonna of recap this all in one you
33:17 , right? So we started with photosynthesis. OK. So the two
33:22 systemss, right? Uh the A P production here um and ad
33:29 So uh the flow of electrons. the whole, the whole thing,
33:35 , plants algae kind of bacteria. we break it down with the two
33:40 . We have um photo system, the green sulfur bacteria can do this
33:48 ad P H formation associated with Uh They are autotrophs. OK.
33:54 And it's anoxic because they're using uh other than um water, right?
34:04 oxygen is not produced. OK. then the last one we just talked
34:10 is the purple non sulfur bacteria. . And so they um will ATP
34:20 for the system for system two um produce um energy. But again,
34:26 heros. OK. So they do on complex organic molecules to oxidize.
34:32 ? Um and so that's all three . Any questions about that? So
34:39 in the super detail here, but kind of just know basically what's going
34:44 , that's really what we're going for . OK. So let's look at
34:51 put a pin in there, so speak the this question. OK.
34:58 which is true. Let me pause concerning photo trophy among halo, a
35:08 bacteria, green sulfur bacteria and non sulfur bacteria. These are four
35:14 that we looked at in the, the photo. OK. And it's
35:39 , I'll talk a little bit about readout potential and, and what that's
35:44 about. OK. Or recap what about? Give you a couple of
35:50 to think about it. OK? Gonna Start Timer. You're 28.
36:33 , OK. Yeah. If you D that's correct. OK. So
36:41 uh remember that's gonna be bacterial adoption . OK. Um Cy bacteria are
36:50 be oxygen and oxygen proponent sulfur light via bacterial chlorophyll. Not with
36:57 OK. So, yeah. D the only one. OK. So
37:03 let's go here. So any Yeah. So let's uh so let's
37:14 this uh next kind of recap, of re rediscuss it a little bit
37:22 a question. Let's just start with question. Then we'll kind of explain
37:25 around. I'll explain it around this . OK. So um which statement
37:32 false among a DC regarding the redox shown? OK. Pass that and
38:01 is the extent if you wanna call , if you wanna call us a
38:04 , this is the extent of the you'll be asked to do. There
38:08 be at least a couple of questions this on the test and you'll see
38:12 , you'll see one on the um as well. That doesn't require a
38:18 to do forward shit. All So let's look at, I'm gonna
38:47 back to this. Let me go . It is true and I'll come
38:53 and we'll look at some of these here. So the way to look
38:59 this table and I get that, like what's going on with this
39:03 OK? So it's best to think it. Well, the way to
39:08 of it is don't even look at yet. All right. Take that
39:15 . It's a table of rankings of electronic sector. OK? So it's
39:21 focusing, focus on that. And so if you have a ranking
39:29 anything right, there's gonna be some are good and some that are
39:33 it's gonna be a uh worst the , right? And so the ranking
39:40 is based on reduction potential, the ability of a molecule to um
39:47 electrons, OK? Reduction potential. we measure that as a plus a
39:52 reduction potential. So we're focused on right now, reduction potential,
39:57 That's what establishes the rank OK. so we can kind of do this
40:06 kind of this is the deviation between and minus, right? We everything
40:11 is plus, everything above is OK. So um so that's one
40:18 , the other thing is to remember this occurs in pairs of molecules,
40:25 ? So you can have, for , we looked at this pair,
40:29 ? Or this pair, right? it could be nitrate, nitrite,
40:36 could be sulfate H two S Every it's all redox pairs. One
40:43 is the form that becomes reduced. the acceptor. And that's what this
40:49 is. It's a ranking of OK? I can make another
40:54 That's a ranking of donors. And if I did that, I'd
40:59 to take, I wanna make, wanna put the I, I put
41:03 blue column with the red with the colum that right? And I wouldn't
41:08 reduction potentials. I put donor I make up something OK? Good
41:15 , right? I put my blue on the red ones that if I'm
41:17 do that, I'm gonna have to the reaction, right? Because if
41:22 going to look at this pair H H two, I'm only looking at
41:27 here as the table does as as a ranking of how good is
41:31 as a accept? OK? Because two is not an acceptor right.
41:39 a molecule that's a donor. And so, um, so like
41:44 things, if something, if if it's bad at something at one
41:48 , maybe it's good at something else that's what this is as well,
41:52 ? If you're a bad uh acceptor weak, right? They use the
41:55 weak and strong. OK? You that in the question, right?
42:00 strong equals something that is good right? Obviously. OK? And
42:07 if you're weak, you're not very at being an accepter, right?
42:10 how do we equate that we equate in terms of the reduction potential,
42:16 ? So one really basic way to about this is electrons are negatively
42:22 right? If you are a good , you have a really high plus
42:28 , right? So think of it plus attracts negative, right? So
42:34 high plus value you're gonna attract lots electrons, you're gonna be really good
42:38 it. So hence oxygen is the OK? The highest reduction potential,
42:43 positive value OK? If you're not good electronic sector, then negative doesn't
42:49 negative, right? Go go apart each other. And that's what these
42:53 are right up here. All negative . So they too have a best
42:58 worst, right? In terms of being good at um uh accepting.
43:04 um so that's kind of how to at this. OK? So if
43:12 then look at the next part Is Delta G. OK. So
43:19 the relationship between reduction potential and delta , OK, that if you
43:25 if you're a bad accepter, This guy um that equates to a
43:31 positive delta G. If you're a good one, good, except for
43:37 oxygen, that's a really high native , right? So, so the
43:43 of combining, so what you try do is have a really good
43:48 right? And have a donor that's good. And a good donor would
43:51 one that releases energy doesn't require energy go. OK. And so if
43:58 going to evaluate the donor, then . And we have to look at
44:06 and we have to reverse The So for example, we look at
44:14 to H plus right plus two OK? And so that's the only
44:21 we can evaluate it as a dope becoming oxidized, giving up electrons,
44:26 ? That's how we do that. right. And so um not like
44:32 . So um so that's how we this. OK? And so we
44:40 to reverse the reaction and reverse the , right? So, and,
44:45 , and reduction potential is not really value you put on a donor as
44:49 donor. We're asking not how, the tendency to accept electrons? It's
44:53 a tendency to give up electrons. . So we, so, you
44:59 , focus on the delta G, ? Um And so the, the
45:03 G will change, right? So we look at H two,
45:07 That becomes a, not a plus a negative delta G, right?
45:13 81. OK. So that's kind how to look at this.
45:19 Um Glucose as a donor, Glycolysis, respiration, right? That
45:26 1 86 minus 1 66 then be G. OK. Metabolism releases
45:32 That's there you go. OK. um so that's kind of how to
45:38 this. OK. Um So if go back to the question,
45:44 Uh A is pretty straightforward, Because we're just reading it off the
45:48 in this fashion, right? It energy, reduced, sulfate. Oh
45:53 , we can see that positive Delta . OK. Sure. B higher
45:58 sulfide would be considered a strong electron . Think of it as a good
46:05 donor, right? What's gonna make good if it releases energy as it
46:09 this? OK. So we have look at the reverse reaction,
46:13 And so that then becomes a minus one. So, all right,
46:22 we look at the reverse reaction, ? So it would be a
46:26 considered a strong killer because of OK. So that's true. The
46:31 trite is a stronger term acceptor than there. Again, we're just reading
46:35 straight off the table, right? Delta G is much different. So
46:42 would be better. OK. So how to look is it help,
46:48 any questions about that? So that's of logic how and how to look
46:52 it. OK. So um you , that's the, that's the logic
46:57 , that's why um that's this is we back up here. Why Um
47:07 to this picture here. Yeah, one that this ah get my pen
47:18 here. OK. That's why this , that's why this specifically,
47:27 This part right here. It all everything we've been talking about the proton
47:33 , the component of electron transport the the the source that the term
47:38 all links together, right? And logic of, of how we can
47:44 this flow this way, which is we need, right? Or what
47:49 needs because that represents uh negative delta . OK? That's needed to pump
47:57 out, all right, that's Then um as they flow back down
48:02 this energy, we use that to a T P S. Um So
48:05 all connected, right? And so , so the choice of source and
48:10 right comes down to energetics. Uh bacteria and they have a variety
48:16 options, right? You play a of different options, for example,
48:20 you put together well a what's available what what is available you try to
48:24 together where it's most favorable, You mean you hopefully a negative delta
48:29 which translates into a strong proton gradient equates to directory equates to how much
48:35 T P S you get. So of course determines how fast you can
48:40 is one factor certainly. But um , it just, it's all
48:45 right? It's why you're sitting there , right? Because of all
48:48 that's happened. OK? Especially in brain tissues. OK? Um So
48:55 I said, hang on day it all boils down to electrons,
48:58 ? In some form or fashion. . Maybe electrons are protons, let's
49:03 , OK. So um I, I do want to um because we're
49:08 about nothing. The last three weeks think, except metabolism. I just
49:15 throw a question at you about something haven't talked about in a while.
49:20 is to see what you remember is as the test is coming up in
49:24 couple of weeks. Let's uh fast . Not this one. This
49:31 viruses. Anybody remember viruses? It's a while. OK. Just uh
49:38 see what you remember. OK. come down here A 210.
51:10 Um Who answered, who was one the 25 that answered h fess
51:20 Nobody. Anybody Give you $100. fess up. Wow. Hey,
51:27 $100? Jeez. OK. Because right, you picked. OK.
51:34 minus single strands aren't a genome It's a template to make a plus
51:40 , right? The plus strand is is the template for translation,
51:44 The minus genome is not that The triage M 13 does not form
51:50 prophage it's in sits inside of a and makes viruses but it's not integrated
51:55 the chromosome. OK. Um CRISPR not a bacteria. It's a,
52:00 a resistance mechanism. Ok. But have temperate sage. No, they
52:07 , they have like cycle and OK. Or any viruses.
52:13 they're commonly uncoded at the cell membrane because they do their stuff outside the
52:19 . Ok. Tropism is not, is describing host range, right?
52:28 is ability to infect multiple cells in same host. OK. And a
52:35 is, that's not true because retroviruses possess a pen. So none
52:42 OK. So that's all I got folks. So we'll see you have
52:47 good week. Uh Hopefully do something . OK? And we'll see you
52:54 here in several days
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