Which type of bonds are found between A-T base pairs?

The correct answer is that there are 2 hydrogen bonds found between adenine (A) and thymine (T) base pairs in DNA. This specific bonding occurs due to the molecular structure and functional groups of the bases involved. Adenine, a purine, can form hydrogen bonds with thymine, which is a pyrimidine, creating a base pair that stabilizes the DNA double helix structure.

In this pairing, the nitrogen atoms in adenine interact with the carbonyl and amino groups in thymine, leading to the formation of exactly two hydrogen bonds. This is significant for the overall stability and specificity of the DNA structure, ensuring proper alignment and pairing of the bases across the two strands. This distinction in pairing is also critical for DNA replication and transmission of genetic information, as it maintains the fidelity of base pairing while allowing for the necessary flexibility and accessibility within the double helix.

The number of hydrogen bonds varies between different base pairs; for instance, guanine (G) and cytosine (C) form three hydrogen bonds, which is part of why G-C pairs contribute to the greater overall stability of DNA compared to A-T pairs.