Complementary base pairs

Definition

Complementary base pairs are specific nitrogenous bases in DNA that form hydrogen bonds with each other; adenine pairs with thymine, and cytosine pairs with guanine. This pairing is essential for the double-helix structure of DNA and accurate replication.

5 Must Know Facts For Your Next Test

1. Adenine always pairs with thymine through two hydrogen bonds.
2. Cytosine always pairs with guanine through three hydrogen bonds.
3. The specificity of complementary base pairing ensures accurate DNA replication.
4. Mutations can occur if incorrect bases pair during DNA replication.
5. Complementary base pairing is critical for processes like transcription and translation in protein synthesis.

Review Questions

• Which nitrogenous bases form complementary base pairs in DNA?
• How many hydrogen bonds connect adenine and thymine? How about cytosine and guanine?
• Why is complementary base pairing important for DNA replication?

Related terms

Hydrogen Bonding: Weak chemical bonds that hold complementary base pairs together in the DNA double helix.

DNA Replication:

The process by which a cell duplicates its DNA before cell division.

Transcription:

The process of copying a segment of DNA into RNA, facilitated by complementary base pairing between DNA and RNA nucleotides.