What is the primary function of phosphodiester bonds in nucleic acids?

What is the primary function of phosphodiester bonds in nucleic acids?

• A. Hydrogen bonds between bases
• B. Ionic interactions stabilize the DNA double helix
• C. Phosphodiester bonds link sugar to phosphate to form the backbone of nucleic acids.
• D. Ester bonds hold nucleotides together within a strand

Answer: (C)

Phosphodiester bonds provide the backbone of nucleic acids. Each bond links the 5' phosphate of one nucleotide to the 3' hydroxyl of the next sugar, creating a continuous sugar–phosphate chain with a defined 5' to 3' direction. This backbone gives the molecule its structural framework and spacing, while the bases extend from it and pair with their complement through hydrogen bonds. The role of base pairing is to hold two strands together, not to form the backbone. Ionic interactions can help stabilize the overall structure in solution, but they don’t define the primary function of these bonds. While phosphodiester bonds are a type of ester linkage, the essential point is that they connect sugar to phosphate to build the backbone of the polymer.

Phosphodiester bonds provide the backbone of nucleic acids. Each bond links the 5' phosphate of one nucleotide to the 3' hydroxyl of the next sugar, creating a continuous sugar–phosphate chain with a defined 5' to 3' direction. This backbone gives the molecule its structural framework and spacing, while the bases extend from it and pair with their complement through hydrogen bonds. The role of base pairing is to hold two strands together, not to form the backbone. Ionic interactions can help stabilize the overall structure in solution, but they don’t define the primary function of these bonds. While phosphodiester bonds are a type of ester linkage, the essential point is that they connect sugar to phosphate to build the backbone of the polymer.