The Why behind Nature’s Choice of Biomolecule | Ramanarayanan Krishnamurthy | TEDxDelNorteHighSchool

The Why behind Nature’s Choice of Biomolecule | Ramanarayanan Krishnamurthy | TEDxDelNorteHighSchool

RNA Structure and Function

  • The speaker, a synthetic organic chemist interested in the origins of life chemistry, discusses the molecule RNA and its structure.
  • Scientists question why RNA is composed of specific components such as ribos, phosphate linkers, and four specific nuclear bases.
  • Experiments involving different sugars and bases revealed that RNA's specific structure provides optimal function and base pairing properties.
  • The speaker highlights the importance of studying alternative structures to understand why a molecule is essential.

Selection of Biomolecules

  • The speaker discusses the concept of "just right" selection, where nature selects molecules that are not necessarily the most complex or efficient but are optimally suited for their function.
  • The speaker emphasizes the role of the environment, particularly pH, in shaping the selection of biomolecules.
  • The pKa values of natural nuclear bases correspond to a pH of around 7, suggesting that the early Earth's pH may have influenced the selection of these bases.

Parallels between Biomolecules and Soap Molecules

  • The speaker draws parallels between DNA and RNA structures and soap molecules, highlighting the role of hydrophobic and hydrophilic interactions in their behavior.


  • Understanding the physicochemical properties of biomolecules at the molecular level can provide insights into higher-order functions and the selection of molecules by nature.

Additional Points

  • Purines and pyramidans are the two types of bases in DNA and RNA with different structures that affect their base-pairing properties.
  • The ribos backbone is the best way to stack the bases in the center and keep them far away from the water molecules.
  • The cyclic structure of the ribose sugar is essential for the base-pairing properties of RNA.
  • RNA is likely a product of chemical evolution as it is the only molecule that can meet all the requirements for functional genetic material.

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