What is the Longest Molecule Ever Discovered?

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SUMMARY

The longest molecule ever discovered is a subject of debate, with examples ranging from DNA and polyethylene to theoretical constructs like covalent bonds spanning the Earth's crust. Key discussions highlight the definitions of molecules, distinguishing between macromolecules such as proteins and lipids, and the implications of polymer length. Notably, the giant polyoxymetalate cluster, consisting of 240 molybdenum, 740 oxygen, and 20 sulfur atoms, is recognized as a significant molecular structure. The conversation emphasizes the need for clarity in defining what constitutes a molecule, particularly in the context of polymers.

PREREQUISITES
  • Understanding of molecular biology concepts, including DNA and macromolecules.
  • Familiarity with polymer chemistry and the properties of polymers.
  • Knowledge of chemical bonding and molecular structure.
  • Basic principles of thermodynamics as they relate to molecular stability.
NEXT STEPS
  • Research the definition and characteristics of macromolecules versus micromolecules.
  • Explore the properties and applications of giant polyoxymetalate clusters.
  • Investigate the synthesis and limitations of long-chain polymers.
  • Learn about the role of thermodynamic fluctuations in molecular formation and stability.
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Students and professionals in chemistry, molecular biology, and materials science, particularly those interested in the definitions and properties of large molecules and polymers.

mollwollfumble
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TL;DR
Longest DNA, nanotube, polymer, silk, nylon, glass, wire
What is the longest molecule? Are we talking about of order of magnitude:
  • 1 metre, eg. DNA, carbon nanotube, polyethylene (UHMWPE)?
  • 1 kilometre, eg. silk strand, monofilament nylon?
  • 100 to 1,000 km, eg. steel wire for suspension bridge, copper wire, optical glass fibre?
  • 12,700 km, covalent bonding connecting the whole of the Earth's crust?
 
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What have you found so far?

Why do you think things you listed count as molecules? What is a molecule?
 
Carbohydrates, Proteins, Lipids, Nucleic acid are Four Large Molecules
 
Seconding Borek's question: you should first learn what defines a molecule. That will make the answer to your quiz quite simple.
 
naresh123 said:
Carbohydrates, Proteins, Lipids, Nucleic acid are Four Large Molecules
Carbohydrates and nucleic acids can each by up to of order two metres long. Aren't proteins and lipids very much smaller?
 
mollwollfumble said:
Aren't proteins and lipids very much smaller?
I think only lipids falls in micromolecules and proteins are macromolecules.
 
I had a professor that said it was the ocean since water is always in the process of taking/borrowing hydrogens. He said that touching a water molecule along the shore here in North America had an effect on a water molecule in Antartica. I always wondered how he would prove something like that...
 
What is the distinction between a crystalline solid (or a metal) and a molecule? There are individual atoms and variously stable agglutinations of atoms: to me the other designations seem arbitrary (and possibly capricious!)
 
An nth-length alcohol or something similar would probably be the longest.
 
  • #10
Can't one make certain polymers as long as is desired? Maybe thermodynamic fluctuations produce a practical limit?? Seems like you just add another monomer.
 
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  • #11
hutchphd said:
Can't one make certain polymers as long as is desired? Maybe thermodynamic fluctuations produce a practical limit?? Seems like you just add another monomer.

That was my understanding. You can just keep stitching carbon atoms on the end in a DNA-Like structure and keep going forever. I wonder if a degenerate star counts as being a molecule? I suppose it has to be pure chemical forces and not gravity holding it together.
 
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