What type of bond holds base pairs together in DNA?

In DNA, the base pairs are held together by hydrogen bonds. This type of bond is particularly suitable for the double helix structure of DNA because it is relatively weak compared to covalent bonds. This characteristic allows the two strands of DNA to separate easily during processes like replication and transcription, where the genetic information needs to be accessed.

Base pairs, such as adenine-thymine (A-T) and guanine-cytosine (G-C), form specific pairs through hydrogen bonding, with A forming two hydrogen bonds with T, and G forming three hydrogen bonds with C. This specificity is crucial for maintaining the integrity of genetic information and the overall stability of the DNA molecule while still allowing for flexible interaction with other molecules.

Covalent bonds, while strong and important within the DNA structure (such as between the sugar and phosphate backbone), do not form between the bases within the strands. Ionic bonds are typically found in interactions between charged molecules, and peptide bonds link amino acids in proteins rather than nucleotides in nucleic acids.