how are the bases held together in dna

The bases in DNA are held together by hydrogen bonds between complementary pairs: A pairs with T and G pairs with C. The sugar-phosphate backbone holds each strand together, while the base pairs “zip” the two strands together in the middle.

Quick Scoop

• Adenine (A) bonds with thymine (T) using 2 hydrogen bonds.

• Guanine (G) bonds with cytosine (C) using 3 hydrogen bonds.

• These bonds are weaker than the covalent bonds in the backbone, which helps DNA strands separate during replication and transcription.

Simple picture

Think of DNA like a twisted ladder:

• Sides: sugar-phosphate backbone.
• Rungs: base pairs held by hydrogen bonds.

If you want, I can also explain why A-T and G-C pair specifically in one simple diagram-like explanation.