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Are All Polymers Hydrolysable?

  1. Jan 26, 2010 #1
    My book is talking about Condensation & Hydrolysis reactions & has said that Polymers are "digested" to become monomers in hydrolysis reactions, i.e. when water is added to a polymer.

    I just want to clarify,

    1) Does adding water to all polymers break them apart instantly? i.e. are all polymers hydrophobic or just specific polymers?

    2) Do amino instantly break apart when added to water or do the side chains attached shield them or something?

    3) Do Proteins instantly break apart when added to water or does the folding shield them or something?

    NOTE: By Shielding I mean would a hydrophobic side chain prevent the water from causing polymers to break apart?


    4) Do these polymers break apart in water because of polar reactions, i.e. the partial charges break apart the bonds?

    For example, in this picture - http://www.bio.miami.edu/~cmallery/150/protein/c8.8x13.hydrolysis.sucrose.jpg

    If I poured sucrose into a glass of water does electronegativity & hydrogen bonds account for these polymers breaking up

    5) Maltose (formed from a condensation reaction of two glucose molecules) is in crackers, (you know crackers - the wafer biscuit things you eat), well when you put them in water they break apart and dissolve...

    Does Hydrolysis explain this, i.e. the polarity of water pulls the molecules of the cracker apart?

    With great sincerity I appreciate any help anyone can give me, thank you :smile:
     
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  3. Jan 26, 2010 #2

    Andy Resnick

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  4. Jan 26, 2010 #3
    Re: Are All Polymers Hydrophobic?

    Yes I'm aware of the distinction.

    1) Hydrolysis breaks apart polymers. What I meant by "are all polymers hydrophobic" was do they "hate" water. I misused it I suppose. I'll restate:

    Does adding water to all polymers break them apart instantly? If so, is this because of polarity and partial charges.

    I'm still hoping for answers to all 5, I've been looking for two hours trying to answer these to no avail.
     
  5. Jan 26, 2010 #4

    Monique

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    Re: Are All Polymers Hydrophobic?

    The answer is no, not all are. Plastics are addition polymers and are notoriously hard to break down.

    The answer is also yes, but only in the case of condensation polymers (water is formed as a by product during the polymerization reaction). The peptide or ester bonds may be hydrolysed by a reverse reaction. It would depend on the reaction kinetics what the direction of product formation is and how easily it is accomplished. Condensation polymers are potential candidates for biodegradable plastics.
     
  6. Jan 26, 2010 #5

    Ygggdrasil

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    Re: Are All Polymers Hydrophobic?

    Most biological polymers (proteins, nucleic acids, carbohydrates) can be hydrolyzed into monomers. However, the activation energy for the hydrolysis reaction is high enough that the hydrolysis reaction does not occur very quickly at room temperature (hence, this is why our cells which are full of water are not falling apart right now due to hydrolysis). In order to get the hydrolysis to occur, you would either need to raise the temperature or add a catalyst (e.g. enzymes that promote the degradation of these biological polymers).
     
  7. Jan 28, 2010 #6
    Re: Are All Polymers Hydrophobic?

    That makes a lot of sense.

    It sems like a great idea, - great for the environment. But if the soymilk in my shopping bag accidentally broke open on my way home the bag would disintegrate via hydrolysis & I'd lose all my shopping :rolleyes:

    I have to give a 2 minute George Carlin link as it is extremely relevant to the discussion



    --------------------------------------------------------

    Also, to expand upon one of my original questions,

    3) Do Proteins instantly break apart when added to water or does the folding shield them or something?

    10 amino acids are hydrophilic due to their R group side chains, so the carboxylic & amine groups are unaffected by the polarity of water (hydrogen bonds don't pull these off of the molecule) & the hydrophilic side chain will not be pulled apart unless the activation energy is considerably higher than 37-42 degrees celsius.

    Is that accurate?

    --------------------------------

    5)Maltose (formed from a condensation reaction of two glucose molecules) is in crackers, (you know crackers - the wafer biscuit things you eat), well when you put them in water they break apart and dissolve...

    Does Hydrolysis explain this, i.e. the polarity of water pulls the molecules of the cracker apart?

    I really messed up my language for this question, I didn't mean to use the term "hydrolysis", I meant to ask does the waters polarity cause the cracker to dissolve in water?

    These are the ingredients : Unbleached wheat flour, water, whole
    ground corn, whole ground wheat,
    canola oil, olive oil, dried onion,
    dried garlic, yeast and sea salt.
    Additionally, rye cracker will contain
    whole ground rye.

    this is a cracker http://classes.uleth.ca/200301/fa2020a/Images/CRACKERS.JPG

    What I'm asking is: do crackers dissolve because the molecular make-up of it's constituents are made of molecules that are pulled apart by hydrogen bonds...?

    :smile:
     
    Last edited by a moderator: Sep 25, 2014
  8. Jan 28, 2010 #7

    Ygggdrasil

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    Re: Are All Polymers Hydrophobic?

    The amide bonds between amino acids in a protein are fairly strong and stable bonds (they bond is slightly stronger than the average single bond because of a resonance structure where there is a double bond between the carbonyl carbon and nitrogen). Protein folding can help protect the amide bonds against hydrolysis. Certainly the amino acids that lie in the interior of the protein and are shielded from water will not be very susceptible to hydrolysis. Furthermore, hydrogen bonding formed between the hydrogen of an amide group and the carbonyl of another amide group will help to stabilize the bond by making the nitrogen's lone pair more available to delocalize over the C-N bond.


    Crackers are mostly made of starch (polymers of glucose). Because these carbohydrates are very polar, they will easily dissolve in water. So, yes, you are correct. Crackers dissolve in water because it is made up of molecules that can form hydrogen bonds with water.
     
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