One strand of a fragment of duplex DNA has the sequence 5'-ATCGACCTGATC-3'.

What term is used to describe the pattern of base pairing between one DNA strand and its partner in a duplex?

Key Concepts

Base Pairing

Base pairing refers to the specific hydrogen bonding between nitrogenous bases in DNA. In a duplex DNA structure, adenine (A) pairs with thymine (T) through two hydrogen bonds, while cytosine (C) pairs with guanine (G) through three hydrogen bonds. This complementary pairing is crucial for the stability of the DNA double helix and ensures accurate replication and transcription.

DNA Structure

DNA is structured as a double helix, consisting of two antiparallel strands of nucleotides. Each nucleotide comprises a phosphate group, a sugar (deoxyribose), and a nitrogenous base. The two strands are held together by base pairing, forming a stable structure that encodes genetic information. Understanding this structure is essential for grasping how genetic information is stored and transmitted.

Antiparallel Orientation

The antiparallel orientation of DNA strands means that the two strands run in opposite directions. One strand runs from the 5' to 3' direction, while the complementary strand runs from 3' to 5'. This orientation is critical for the mechanisms of DNA replication and transcription, as enzymes that synthesize new DNA or RNA can only add nucleotides to the 3' end of a growing strand.