Largest organic compouds

Discussion in 'Chemistry' started by Chatha, Mar 2, 2007.

  1. Hercules Rockefeller Beatings will continue until morale improves. Moderator

    Only one person has answered correctly. DNA is by far the largest organic polymer in existence. Nothing else comes close. Let’s take human chromosome 1 (the largest human chromosome but not the largest chromosome in nature) as an example:

    A chromosome is comprised of one continuous double stranded molecule of DNA. The two stands are held together by hydrogen bonding, so each single strand is its own distinct molecule.

    Chromosome 1 has 247,249,719 bases (each strand).

    • Purines (adenine and guanine) have 5 carbon atoms.

    • Pyrimidines (cytosine and thymine) have 4 carbon atoms.

    • Ribose has 5 carbon atoms.

    • Phosphate has no carbons (PO[sub]4[/sub][sup]-[/sup])

    So, let’s use the average of the number of carbons found in purines and pyrimidines for each position in the DNA strand:
    4.5 carbon atoms.

    Each position on the strand is comprised of a base (either purine or pyrimidine), a ribose and a phosphate. These three items together are called a “nucleotide”.

    Total carbons for each nucleotide (base + ribose + phosphate) is:
    4.5 + 5 + 0 = 9.5 carbons.

    Multiply this by the number of nucleotides in chromosome 1........

    9.5 x 247,249,719 = 2,348,872,330 carbons!!!!

    My quick calculation of the complete formula for the DNA molecule in chr1 is:


    This may be a little off as I have taken averages for the composition of the four nitrogenous bases, but it will be pretty close.
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  3. Positron Agony: Not all pain is gain Registered Senior Member

    Well I would agree DNA is the largest organic molecule but that's something most people know already. I'm still curious as to the Second largest though.
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  5. Facial Valued Senior Member

    DNA is a coded polymer, meaning that it would have monotonous digital properties.

    Just about every other polymer, outside RNA, would carry no information and have a single monotonous analog property.

    A protein is very large, and in general they have non-monotonous, or unique, analog properties.

    It really depends on what functional properties you want to look at.
    If it's all-out biggest, then I would probably say a protein polymer, such as spider silk (I don't know the actual one).
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  7. Chuch Registered Member

    Buckyballs are kinda large but they have a long way to go for being the largest. However they are most certainly smooth and very nice to look at.

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    Honestly I find fullerenes very impressive. You can hear about new idea or invention concerning these almost every day.

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  8. exchemist Valued Senior Member

    I'd nominate graphite I think. Any giant structure can be made large enough to exceed the molecular weight of the largest molecule. And graphite is simply the extreme case of the fused ring category of organic compounds.

    But in a way it's a slightly silly exercise.
  9. DaveC426913 Valued Senior Member

    Is graphite a molecule? I thought it would be a crystal. Aren't they bound differently?
  10. exchemist Valued Senior Member

    Yes, it's a giant structure. But the OP asked about organic compounds, not molecules specifically. (And molecules form crystals, too.)

    I have my tongue a tiny bit in my cheek, but when you consider fused ring systems, for example pyrene:
    or the asphlatene family (familiar to me from my time in the hydrocarbon industry):, you can easily see that by fusing more and more 6-members aromatic rings you eventually end up with a graphite sheet.

    One can argue the toss as to whether graphite should be classed as "organic" or "inorganic", but it is in effect the limit case of a fused aromatic ring structure, with sheets stacked on tope of one another and bound by Van der Waals forces.
  11. DaveC426913 Valued Senior Member

    I understood that carbon alone is not considered a sufficient qualifier to be organic.

    Seems by some accounts, organic is synonymous with hydrocarbons,i.e.: carbon backbone with hydrogens.
  12. Write4U Valued Senior Member

    From wiki
    Hazen calls these the cause for the rare species which emerge in specific environments, the rare species which combined have a larger bio-mass than the entire population of the earth.

    Well, we know that we have at least one chromosomes which is twice as long as was originally designed.
    And an actual visual of the modified chromosomes is demonstrated here:

    One less chromosome than apes, but twice its normal size....

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    Last edited: May 1, 2018

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