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Water in other substances and extracting it.

  1. Jan 20, 2004 #1
    Before I can even pose a question, I need to know whether or not the water is chemically bonded to the other substances in things like juices and fruit.

    If it is chemically bonded, it the seperation of water from these molecules something done by digestive enzymes, or a process which uses ATP?
     
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  3. Jan 20, 2004 #2

    FZ+

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    What do you mean "chemically bonded"?

    I think it is usually a case of suspension, or solution. Osmosis and filtration is enough.
     
  4. Jan 20, 2004 #3
    I'm pretty much a layman, so I probabally used bad terminology.

    I meant, essentially, in something like orange juice, is it just water with other things suspended in it, or does the water form any sort of bond which would take any expendature of ATP to seperate the water from whatever substance it might be bound with.
     
  5. Jan 21, 2004 #4

    Monique

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    Water is very good at forming Hydrogen bonds with polar substances, but these are non-covalent interactions. The best way to extract the water would probably be destillation.
     
  6. Jan 21, 2004 #5

    Another God

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    I think the answer you are looking for is that everything is Desolved into water....just like salt. Orange juice for instance, just happens to be water with a lot of stuff in it which happens to be specific for oranges. Distillation is simply a process of turning the water into gas so that it leaves all of the dissolved substances behind as the gas floats away. The steam is then cooled back down to liquid temperature again into a container that is seperate from the first.

    this is the most basic purification technique available (although it doesn't really purify. The steam can carry some stuff along with it. It will get rid of most of it though)

    And yes, any aqueous thing is water with solutes in it. Milk, Juice, Acid, Detergent, blood etc included.

    I think alcohol is one of the rare exceptions, and then other obvious liquids like mercury..and there are a few more.
     
  7. Jan 21, 2004 #6

    Nereid

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    minerals

    wasteofo2, would you mind clarifying a bit further? I read your initial question quite differently: is water (H2O) bound chemically to other substances?
    And the answer is yes!

    In geology, there are a lot of mineral pairs which differ only in that one has 'water' in it and the other doesn't. For example, anhydrite (calcium sulphate) and gypsum (hydrated calcium sulphate)
     
  8. Jan 21, 2004 #7
    I don't believe what he is talking about is a chemical bond. They are "intermolecular forces". In this case Hydrogen bonding, which is not an actual bond, in fact it is only 5% as strong as a covalent bond. It would, also, have some dipole-dipole and london (dispersion) forces,but these would be insignificant. I believe Monique was correct in mentioning distillation or in some cases vacuum filtration would even work.

    Nautica
     
  9. Jan 21, 2004 #8
    Not really non-covalent interactions!
    Hydrogen bond is about 10% covalent bond, formed by electrons delocalized from sigma bond! A credit to this discovery goes to L. Pauling, and some to humble me :) (Not knowing for his work), of course nothing without HUP.

    Extracting the water ? Usually you extract something out of water, but there’s no real difference, in both cases you get water and something;). Most common way is working with polar and non-polar solvent (e.g. using proper hydrophobic solvent you’ll get separated water from more hydrophobic molecules in two phases, and similar) …
     
  10. Jan 21, 2004 #9

    Monique

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    Some to you? Explain more.. :)

    Um, yes, but water is extremely good is solvating substances, there will be a lot of stuff in it..

    For a bottle of orange juice, I'd centrifuge the sample, boil the supernatant, cool the steam, this will already be relatively pure, you can make it purer by restricting the boiling temperature at which you condensate the gas. But it greatly depends on the scale you want to do it at.. I wouldn't recommend using a boiler to purify water for city supply..

    You can use reactive carbon to pull out contaminants or filter it through piles of sand (dunes), but I don't think the purification process was asked for in your inquiry :P
     
  11. Jan 21, 2004 #10

    Monique

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    Actually an interesting thing I'd like to mention not really related, but a little it is.. it is about the three-dimensional structure of bacterial K+ ion leak channel and why they conduct K+ better than Na+ (while Na+ is smaller).

    size of K+ 0.133 nm (is conducted 10,000-fold better)
    size of Na+ 0.095 nm

    Turns out that for a K+ ion to enter the filter, it must lose almost all of its bound water molecules and interact instead with carbonyl oxygens lining the selectivity filter.

    So why you ask, can't the smaller Na+ pass through more freely?

    Well, the carbonyl oxygens are too far away from the smaller Na+ ion to compensate for the energy expense associated with the loss of water molecules, required for its entry :)

    Smart people those chemists to figure that out :)
     
  12. Jan 21, 2004 #11
    I'm not good at asking questions it would seem.

    What I wanted to know is: When you drink something, like orange juice, milk, soda etc. by what means, in the body, is the water seperated from the other things in it which made the solution you drank. Also, does the seperation of water from everything else take the expendature of ATP?
     
  13. Jan 21, 2004 #12

    Another God

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    Since the water isn;t really attached to the substance, it is never 'seperated' physically. Remember that we are essentially all water....with stuff in it....

    If we drink or eat something with water in it, the water is the fluid upon which that subjstance is moved around in. But the substance itself is the only thing that is reacted with or used etc, while the water is present so it can be used... Everything in biology happens in an aqueous environment.
     
  14. Jan 22, 2004 #13

    Monique

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    Maybe you are interested in how the bowel absorbes liquids, since in sickness we get diarrea? Or how kidney's work maybe too?
     
  15. Jan 22, 2004 #14
    I was actually interested in whether or not ATP was used to get water from things like juice to determine if it wasmore beneficial to get the water for respiration from pure water.
     
  16. Jan 22, 2004 #15

    Monique

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    Then why didn't you say so in your first post
     
  17. Jan 22, 2004 #16
    The OJ you drink is mostly water. It's got some suspended solids in it in the form of pulp, which gets digested by acid in your stomach. It's got a lot of sugars, and vitamins, and other various biological compounds in it. When it gets to your intestine, the water, and other compounds, is taken through your intestinal wall, and to the necessary parts of your body via the blood stream. the water itself spreads mostly through diffusion. The OJ is mostly water, but so are your intestinal fluids, your intestines, your blood, and every single cell in your body. If you ran a labelling experiment and drank labeled water, in a very short amount of time that water would be just about everywhere in your body. So it does not take any energy to take in water. Since your intestinal wall is essentially a semipermeable membrane, you can chalk this up to osmosis.
     
  18. Jan 22, 2004 #17

    Monique

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    Water uptake in the bowel
    http://www.siumed.edu/mrc/research/nutrient/gi42sg.html

    It is a passive process based on osmotic gradients. So wouldn't pure water pass through more readily?

     
  19. Jan 23, 2004 #18

    Another God

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    In theory, yes... If it is based on osmotic pressures, then pure water would increase the osmotic pressure dastically and diffuse outwards. On the other hand, assuming OJ had a lower salt conc. than your body, it would also raise the pressure and push outwards too, so you could drink tons of OJ and raise the osmotic pressure quickly through shear volume.

    *shrugs*
     
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