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Some general bio concepts

  1. Jan 23, 2005 #1
    which of the following will most likely be disrupted by a change in pH?

    1) hydrogen bonding
    2) ionic bonding
    3) hydrophobic interactions
    4) disulfide bonds
    5) neither

    -I'm pretty sure its not 1) and 2) since changing the pH won't affect the electronegativity of an atom...Pretty sure that its not disulfide bonds either, so from that im guessing that its hydrophobic interactions..am i right? or is my concept wrong?

    A nucleotide containing a purine, ribose, and a phosphate group could be a building block for?

    a) dna
    b) mRna
    c) tRna
    d) rRna
    e) b,c,d

    -Ok it is NOT A for sure, so im assuming that a nucleotide contaning a purine, ribose, and phosphate group could be a building block for all b,c,d....am i right ? or am i missing an important concept?

    A DNA molecule with 5'ATCGTAC3' = 3'TAGCATG5' right?

    If one thousaidn glucose molecues arrive in a cell, and the 1000 glucose molecules join together into a starch molecue, what changes occured with the synthesis of the starch molecule?

    -well this is an anabolic pathway since we are building something small into something bigger. So entropy decreases, since this is a non-spontaneous system. However, does the entropy of the universe decrease, or the entropy of the cell decrease?

    Dehydration syntehisis will decrease entropy within a system right? since its the formation of smaller molecules into bigger ones?
  2. jcsd
  3. Jan 24, 2005 #2


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    You are right it is not A. Ribose is in all the type of RNA. rRNA requires some protein component. tRNA also require an amino acid to be complete. Although, C and D would be incomplete, they, however, only ask for building block, and E is the answer

    It is right but you should put in 5' to 3'
    5' GTACGAT 3'
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