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Very very easy question about size of macromolecules

  1. Apr 28, 2010 #1
    Hello guys,

    I have a very quick question. They say nucleic acids are very large molecules and they cover some large distance I can not remember. Are they saying the length of these molecules are long or the size(meaning they are big with width). I don't understand how they can fit in a cell if they are that big. I can understand how they can wind a lot inside a cell, but that only explains the length. It is those trivia like things where they say this can cover the size of a tennis court and such things. Just give me your opinion. Thanks :smile:
  2. jcsd
  3. Apr 28, 2010 #2


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    This may be useful: http://en.wikipedia.org/wiki/DNA" [Broken]. Does this link answer your questions?
    Last edited by a moderator: May 4, 2017
  4. Apr 29, 2010 #3
    Let's look at chromosome 1. It has ~250million base pairs. Each base pair is about 3.4 angstroms long. And 1 angstrom = 1x10-10 meters.

    250 million base pairs x 3.4angstroms/base pair = 850 million angstroms long.

    850 million angstroms x 1x10-10meters/angstrom = .085 meters. Chromosome 1, the largest chromosome, is roughly 8.5centimeters long when stretched out completely. What allows such a long molecule to fit into a small nucleus are the histone proteins that wind DNA into tiny spindles, which are then wrapped around themselves again.

    If it helps, if you could cut a meter stick into a billion pieces, each piece would be 10 angstroms long.
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