What is complementary base pairing?

Complementary base pairing refers to the specific hydrogen bonding interactions between nitrogenous bases in nucleic acids. In DNA, adenine (A) forms hydrogen bonds with thymine (T), and cytosine (C) forms hydrogen bonds with guanine (G). This pairing is highly specific: adenine always pairs with thymine, and cytosine always pairs with guanine. The specific shapes and chemical structures of DNA bases facilitate the efficient formation of hydrogen bonds between complementary pairs. The consistent pairing of bases in DNA ensures accurate replication, transcription into RNA, and translation into amino acids. In RNA, uracil (U) replaces thymine (T) as the complementary base to adenine (A). Therefore, the complementary base pairs in RNA are: Adenine (A) pairing with Uracil (U) and Cytosine (C) pairing with Guanine (G).