/sci/ - Science & Math

>>6920200
What do you mean by constant displacement of electricity?

>>6920107
The entire cable has electrons. The appliances that run on electricity have electrons. Alternating current does not "supply" new electrons; it moves the electrons that already exist.

>>6916655
That's fair. He was arguing against an older model which has apparently been abandoned.

>>6915847
http://www.pnas.org/content/69/12/3561.full.pdf
http://www.bme.umich.edu/labs/biomembrane/publications/papers/insulating_tethered_lipid_bilayers.pdf

Neither of these studies measured the resistance of a cellular lipid membrane; they measured the resistance of artificial lipid membranes.

Earlier, you said:
> Applying a voltage to a cell and measuring the current shows a high resistance.

But that's not what you've demonstrated

>>6916573
That does not seem to be the case. When nafion is placed in an environment with water and latex microspheres, the microspheres are excluded from a zone (the EZ) around the nafion. This also happens with other hydrophilic surfaces, like a piece of muscle.

The size of the EZ is a function of the amount of light, especially infrared light. The EZ also has interesting properties:

It is charged. Placing electrodes in the EZ and immediately beyond it causes a current to flow.
It has high pH.
It is denser than bulk water.

This does not seem to require a catalyst. Especially, a piece of muscle tissue produces the same effect, which suggests that a similar effect may occur within a cell.

>>6916472
>the surface of the muscle itself will be moist even if exposed to air, which will allow sodium ions to accumulate, and muscle fibers are permeated with blood vessels which are contiguous with outside surfaces but would almost certainly retain moisture despite his centrifugation protocol.
I had not thought of this, but it is possible.

>Ling also directly states that he assumes that the bulk of intracellular ions are free in the cytoplasm - this is patently false.
This is not what Ling believes. This is his impression of the membrane-pump model, which has apparently changed since the time of that writing.

Anyway, thank you for providing an intelligent response.

>>6916416
>Hydroxide would reduce OsO4 to a compound with a distinct purple color. OsO4 stains are black. There is little if any osmium reduction if it's not purple, so it certainly isn't coordinating with -OH at the edge of the cell.
Then it might not be reacting with the hydroxides. But it has been demonstrated that osmium tetroxide will stain a gelatin gel, which is essentially protein and water, and an analog of a cell under the AIH.

>Charged groups and ions cause water to solvate around them, not split.
Light, especially infrared light, causes the water to split. The charged amine and carboxyl groups cause these water and hydroxides to form a structure. In Gerald Pollack's work, light, especially infrared light, increases the size of the exclusion zone.

>That's specifically regarding glcoSPHINGOlipids, not glycolipids in general. It's a subset.
Yes, though I did not see a comment about glycolipids in general.

>>6916310
Then please tell me what it shows.

>>6916241
>Gelatin contains lipoproteins.
What? Gelatin is protein. It's pure protein. It's hydrolyzed collagen. Collagen is a protein.

Gelatin is not a lipid!

>DO ALL POLAR SUBSTANCES HAVE DOUBLE BONDS FOR OSMIUM TETROXIDE TO REACT WITH
No, and nor do many lipids. Osmium tetroxide oxidizes things, making polar products. Osmium tetroxide staining is an indicator of oxidizability and the products are polar.

If osmium tetroxide staining were a good indicator of lipids, it would stain tripalmitin. But it does not.

Osmium tetroxide stains gelatin gels (not a lipid), which further demonstrates it is not an indicator of lipids.

Osmium tetroxide can stain unsaturated lipids, because they are oxidizable, but its presence does not indicate a lipid.

Again, if gelatin contains lipoproteins, please prove that, because even Wikipedia disagrees with you on that. According to Wikipedia:

>Gelatin is a mixture of peptides and proteins produced by partial hydrolysis of collagen
>Collagen is the main structural protein of the various connective tissues in animals.

>>6916229
>If model membranes are produced in aqueous solutions, why would the dyes have any specificity when water is polar?
Osmium tetroxide is a Lewis acid and an oxidant. It binds to Lewis bases and things it can oxidize. Hydroxide is like that, but bulk water is not.

>What induced this charge and what maintains it?
This is a longer answer. Gerald Pollack's work demonstrates it. In cells, extended proteins have charged amine and carboxyl groups. The water bonds to these, more water bonds to that water, etc.

>How does one charge water in the first place?
Split it into hydronium and hydroxide.

>What atomic structure does charged water have?
Ice is hexagonal sheets, with protons between them to hold them together. Structured water appears to be hexagonal sheets with the protons excluded. The sheets are stacked atop each other, but staggered, so positive parts are adjacent to negative parts. This holds the structure together and the exclusion of protons makes it negative. Gerald Pollack has demonstrated this fairly well.

>>6916229
from your study:
>Folch extraction of labeled cells and analysis of the upper phase revealed little if any [3H]fucose-labeled glycosphingolipids.

Also, that's not even the same study. You (I'm assuming you're the same Anon) presented a study earlier in which you claimed fucose was a lipid precursor. But in that study, I saw no indication that fucose was incorporated into lipids. So I don't think that study on membrane ghosts proves anything.

>>6916241
>Yes. how does that contradict what I said? Does the paper state anywhere that osmium tetroxide is staining anything besides lipid moieties?
Here's what you said:
>That study specifically states it's testing tissues. Tissues made of cells. Cells with lipid bilayers.
Bovine pancreas is a tissue with cells. Gelatin gel is not.

>Does the paper state anywhere that osmium tetroxide is staining anything besides lipid moieties?
Gelatin gel is not a lipid moiety.

>>6916161
>That study specifically states it's testing tissues. Tissues made of cells. Cells with lipid bilayers.
Here's a quote from the paper itself:
>As test objects served 0.5-1.0-cm cubes of gelatin gel (30% and 40% gelatin in Na-barbital-acetate buffer, pH 7.2, and bovine pancreas.
They used bovine pancreas, a tissue. They also used gelatin gel in a Na-barbital-acetate buffer (which had pH of 7.2).

>Again, you haven't explained why osmium tetroxide suddenly stains charged water, when we have never seen this phenomenon. It really should be easy to get a picture of stained charged water if it's true. Where is it?
Every picture of a cell stained with osmium tetroxide. Or the study previously posted. The water in gelatin gel is structured in the same way.

>>6916157
>Tripalmitin has no phospholipid head, therefore it does not bind to it.
If the presence of a polar phospholipid head is necessary for osmium tetroxide binding, then it cannot be said to be an indicator of lipids. It's an indicator of polar substances.

>>6916076
>If the dye selectively binds to lipids (demonstrated in the models), why wouldn't it bind to the lipids in the cells?
The phospholipid heads are polar. If something binds to the phospholipid heads, that does not imply that it binds to lipids. That implies it binds to polar things. It might bind to the polar head of amphiphatic lipids, but that's irrelevant, because all we see is it binding to something polar.

>If structured water excludes solutes, how would these dyes make their way to both sides of the interface to form two rings?
They're beyond the structured water. The effect is an electrical double layer:
http://en.wikipedia.org/wiki/Double_layer_(interfacial)
The structured water is charged and the double layer forms beyond it.

>And that fucose is demonstrably used to produce glycoproteins.
Are these lipids? How is that relevant?

>>6915931
>>6916084
Whoops, I posted the wrong study. Sorry! Here's what I meant to post:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1072717/pdf/jcinvest00750-0067.pdf

Potassium is only pumped IN when rubidium or cesium are absent.

>>6916031
Behold: osmium tetroxide stains gelatin!
http://jhc.sagepub.com/content/16/3/157.short

Gelatin is an analogue of the model of the cell I believe, so this is completely consistent with my model.

If osmium tetroxide only stains lipids, why does it stain gelatin and not tripalmitin?

>>6916028
>Rubidium has been known to be an analogue for potassium for some time, so no, no rubidium pump is necessary.
If rubidium is an analogue for potassium, then why does the presence of rubidium cause potassium to be pumped out? If the two are interchangeable, then both should be pumped in.

>>6916031
>No, it's completely correct that osmium tetroxide is a lipid stain.
It's a Lewis acid. That means it bonds to Lewis bases, not lipids. It doesn't even stain tripalmitin.

This is the standard explanation for osmium tetroxide:
It diffuses into the lipid membrane, reacts with the double bonds in hydrocarbon chain, forms polar compounds, and diffuses out to bond with the phospholipid heads.

But we don't see all of that. All we see is two dark rings. Supposedly, those are the phospholipid heads. But the two dark rings give us no indication that the osmium tetroxide originally stained a non polar hydrocarbon; that's just postulated. All we see is the end product.

Two dark rings are also explained by the electrical double layer:
http://en.wikipedia.org/wiki/Double_layer_(interfacial)

>>6915925
>http://link.springer.com/article/10.1186%2F1746-4811-8-28#page-1
That's just a review article. Show me an experiment and I'll give you my response.

>Is that a common occurrence? Why would unincorporated fructose do that?
I see you did not read your own study. They used fucose, NOT fructose. Read your study.

If the lipid membrane takes up fucose, a polar molecule, then that gives no indication of the membrane being a lipid. Here is an alternative explanation of what was observed:

A cell was punctured. This did not destroy it. Then it was exposed to fucose (not fructose). It absorbed some fucose. The end.

You previously called fucose a "lipid precursor." How is that even relevant? A cell took up fucose, a sugar.

>If hydroxides are all over inside cells, why would the tetroxide be concentrated at the outside?
This was already covered. Structured water excludes solutes:
>>6913935

>>6915874
Originally, I asked for evidence for the lipid membrane. Your response is now to ask me for evidence for the model I believe. I'd still like to know what I originally asked, i.e. when was the lipid membrane first proven? Which experiments verified it?

>Show an example of evidence for AIH
Gerald Pollack's work was posted earlier in this thread. He has demonstrated that hydrophilic surfaces structure water in a way that excludes solutes. That is the basis of AIH. You can see it happen in real time. Solutes are excluded, no lipid membrane necessary.

Here's more evidence for the AIH:
http://jp.physoc.org/content/280/1/105.short

Among the alkaline metals, the ion with the highest atomic number is accumulated, while all others are excluded. This contradicts the lipid membrane model, in which the Na/K ATPase always pumps potassium in. Also, to be consistent with the lipid membrane model, accumulation of rubidium would require a rubidium pump. Yet somehow, this pump also reverses in the presence of cesium.

>You've been given several pieces of evidence. All you've done so far is either ignore them or call them interpretations.
They are interpretations. When we see two dark rings around a cell, that's an observation. When we say it's because the dye is binding to phospholipid heads, that's an interpretation. It's not directly evident. It's the lipid-membrane-model's explanation of the evidence.

>You have not explained why freeze fracturing and dissecting the membrane shows lipid molecules
I don't think it does. This was discussed earlier:
>>6914528

Freeze fracturing shows something, and it was assumed to be the lipid membrane, because that was the only way to interpret it consistent with the existence of the lipid membrane.

>You have not explained how every lipophilic stain is being fooled by charged water.
People said osmium tetroxide is a lipid stain and that turned out to be totally wrong. That was also discussed earlier in this thread.

>>6915789
>Dyes like HTMA-PFP behave the same in artificial lipid membranes and in vitro/vivo. We know how they bind to lipids in artificial scenarios
Show me an example. People basically said the same thing to me about osmium tetroxide and it turned out to be totally different.

>>6915808
I asked for an example, not a definition of resistance. Show me an example of resistance across a cell membrane.

>>6915808
I asked for an example, not a definition of resistance. Show me an example of resistance acro

>>6915560
Also, I read most of your study:
http://www.jbc.org/content/246/16/5162.full.pdf

I don't think it shows what you think it shows. They "ruptured" cells and collected what was left over. They assumed this was only the membrane, because they assumed that the rest of the cell would leak out without a membrane to hold it together. That's their assumption.

Then they showed these "membranes" incorporated the various tagged substances, like fucose (a sugar). You call these lipid precursors. I admit fucose, as a sugar, can be a lipid precursor. Sugars can be converted into fat via de novo lipogenesis. But this study gave no indication that this had happened. They just found fucose in the "membranes."

So really what happened is they punctured cells, exposed them to fucose, and found fucose in whatever was left in the cells. If cells have no membrane and the cytoplasm sticks together all on its own, then the cell would still be somewhat intact after the rupturing. So it's not surprise that it absorbed some sugar.

I don't see how this proves a lipid membrane. And why would a lipid membrane take up sugar?

>>6915791
>That assumes the cell membrane doesn't spontaneously reform after cutting, which we already know lipid membranes
First, this does not seem realistic, based on experience. A punctured bubble pops; it does not reform. If a lipid membrane were punctured, one would expect the hydrophobic portions to congregate, rather than to push through the water to re-connect.

Anyway, someone made the same argument before and posted an experiment that supposedly showed the "spontaneous reforming" of the lipid membrane. That's not what it showed.

In the experiment, they punctured the cell and measured the amount of calcium that leaked in. Because very little calcium leaked in, they took that as evidence that the lipid membrane reformed. I don't believe in a lipid membrane and structured water has already been demonstrated to exclude solutes, so their interpretation is not the only one.

This is what I see every time. Someone conducts an experiment and they interpret the results under the assumption that the lipid membrane exists. Then they present this experiment to me and say "See? This demonstrates the lipid membrane!" No. You interpreted it in a way that involves a lipid membrane.

Can you show me an experiment in which the lipid membrane definitely reforms?

>>6915777
>No, it's the interpretation of scientists whose job is to interpret the evidence.
Appeal to authority.

>That's my point. Charged water would show low resistance. Nonpolar hydrophobic molecules resist electrically charged species, which means high resistance.
Then give me an example of what you mean.

> Lipid stains are not attracted to charged water.
Give me an example. People said the same thing about osmium tetroxide and it turned out to be totally different.

>>6915721
It takes more than just a picture to prove a model. Explain this:
http://jp.physoc.org/content/280/1/105.full.pdf+html

It directly contradicts the idea of a lipid membrane. In fact, the entire purpose of the experiment was to disprove the lipid membrane, and it appears to do so.

>>6915716
>Applying a voltage to a cell and measuring the current shows a high resistance
Okay
>This is due to the hydrophobic core of the lipid membrane.
That's your interpretation.
>If the membrane was water we would see a lower resistance.
It depends on the state of the water. "EZ" water is charged, as has been demonstrated by Gerald Pollack. Cell water is not liquid bulk water.
>Fluorescence microsocopy with lipid stains shows the structure of the bilayer.
That's your interpretation.
> And no if the membrane was made of water, these dyes would not adhere to the membrane.
I don't think you appreciate the model I'm presenting, because you misrepresent it.

>The AIH cannot explain these results.
Your incorrect impression of the AIH cannot explain these results. If cell water is charged, it creates an electrical double layer.
http://en.wikipedia.org/wiki/Double_layer_(interfacial)
That explains the double-ring image you see.