Study Guides/Biology/Phosphodiester Bond
Study Guide · Biology

What is a Phosphodiester Bond?

In Biomolecules (Class 11 Biology / Chemistry), understanding how DNA and RNA are built is essential. The structural 'glue' that holds our genetic code together is the Phosphodiester Bond.

Question (Click to Flip)

What is a phosphodiester bond?

Answer

A phosphodiester bond is a strong covalent bond that links the phosphate group of one nucleotide to the sugar of another nucleotide. It is responsible for forming the sturdy sugar-phosphate backbone of DNA and RNA.

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Key Facts

Function: It connects nucleotides together to build DNA and RNA polymers.

Location: It forms the 'Sugar-Phosphate Backbone' of the DNA double helix.

Chemical Link: Connects the 3' carbon of one sugar to the 5' carbon of the next via a phosphate group.

What is a Phosphodiester Bond?

A Phosphodiester Bond (or linkage) is a strong covalent chemical bond that links nucleotides together to form the long chains of DNA and RNA.

  • Think of DNA like a ladder. The 'steps' of the ladder are the nitrogenous bases (A, T, G, C), but the long 'side rails' of the ladder are made of sugars and phosphates.
  • The phosphodiester bond is the exact chemical link that connects the phosphate group of one nucleotide to the sugar molecule of the next nucleotide, creating this strong, unbroken 'Sugar-Phosphate Backbone'.

How does it form?

In chemical terms: It forms when exactly two hydroxyl (OH) groups in phosphoric acid react with hydroxyl groups on two other molecules (the sugars) to form two ester bonds. Specifically, it links the 3' (three-prime) carbon atom of one sugar molecule to the 5' (five-prime) carbon atom of another sugar molecule.

Questions and Answers

What is a phosphodiester bond?+

A phosphodiester bond is a strong covalent bond that links the phosphate group of one nucleotide to the sugar of another nucleotide. It is responsible for forming the sturdy sugar-phosphate backbone of DNA and RNA.

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