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How can something hydrophobic hydrogen bond?

  1. Mar 15, 2008 #1
    1) The nitrogenous bases of DNA hydrogen bond with each other yet they are also characterized as hydrophobic? How can something hydrophobic hydrogen bond?

    2) How many chromosomes are present in a human somatic cell after S phase (DNA replication). Is it still 46 or 92?
  2. jcsd
  3. Mar 15, 2008 #2
    Where have you read that there are Hydrophobic bonds? In protein structure, I have only heard of Hydrophilic Bonds, where have you got that information from?

    It does seem a bit funny that something can be hydrophobic and still not be repelled by a hydrogen bond which is what water consists of. If this is the case, I guess I will have to let someone else takke over from here :smile:
  4. Mar 17, 2008 #3
    There aren't hydrophobic bonds, but the nitrogenous bases are hydrophobic. This is why they are on the inside of the double helix, away from the aqueous environment. My question is: How can the bases be hydrophobic and still have hydrogen bonding?
  5. Mar 19, 2008 #4


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    When you're talking about hydrophobic bases, you have to think about the whole molecule and what parts are exposed to the "outside." The hydrophobic part is what is left "sticking out" after the DNA is all assembled. There can still be local hydrogen bonding in other parts of the molecule. You'll get this same concept with amino acids and protein folding.
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