Question

What does it mean when it is said that both DNA chains have antiparellel polarity?

Answer 1

Anti-parallel Polarity

1. The phosphate groups at the start of two DNA strands (poles) are in the opposite location in anti-parallel strands of DNA.
2. Because the two DNA strands are antiparallel and have opposing polarity, the 5' end of one strand faces the 3' end of the other and vice versa.
3. This means that if one chain has a polarity 3′->5′, then the other has 5′->3′.
4. The base pairs complement each other due to the antiparallel orientation.
5. Antiparallel DNA is structurally more stable than parallel DNA.
6. Two chains in the DNA double helix have anti-parallel polarity in their sugar-phosphate backbones.