Question

What type of bonds does base-pairing in DNA involve?

Answer 1

The bases are being "paired" with 2 or 3 hydrogen bonds.

Explanation:

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.
A-T
G-C

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.