What type of bonds does base-pairing in DNA involve?
In DNA, 4 different base pairs are lined up in two strands to create a certain sequence that, in the end, codes for many different proteins. The 4 different bases are:
- Adenine (A)
- Thymine (T)
- Guanine (G)
- Cytosine (C)
Adenine will normally pair up with thymine, and guanine will pair up with cytosine.
Between both pairs, hydrogen bonds play the main role of holding them together. The difference between the two pairs is that between A and T, there are 2 hydrogen bonds, while between C and G, there are 3 hydrogen bonds.
This explains why, for example, C-T pairing is unfavourable.