Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Complementary base pairing is the specific hydrogen bonding between purines and pyrimidines in DNA. Adenine pairs with thymine, and guanine pairs with cytosine.
5 Must Know Facts For Your Next Test
Adenine (A) always pairs with thymine (T) through two hydrogen bonds.
Guanine (G) always pairs with cytosine (C) through three hydrogen bonds.
Complementary base pairing is essential for the double helix structure of DNA.
Errors in complementary base pairing can lead to mutations during DNA replication.
This principle is critical for processes like DNA replication and transcription.
Review Questions
Related terms
Hydrogen Bonding: Type of weak chemical bond that occurs between a hydrogen atom and a more electronegative atom.
Purines: Double-ring nitrogenous bases in DNA; includes adenine and guanine.
Pyrimidines: Single-ring nitrogenous bases in DNA; includes cytosine and thymine.