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

What is the sequence of the other strand in the duplex?

Key Concepts

Complementary Base Pairing

In DNA, the two strands are held together by complementary base pairing, where adenine (A) pairs with thymine (T) and cytosine (C) pairs with guanine (G). This means that for every A on one strand, there is a T on the opposite strand, and for every C, there is a G. Understanding this pairing is essential for determining the sequence of the complementary strand.

DNA Directionality

DNA strands have directionality, indicated by the 5' and 3' ends. The 5' end has a phosphate group, while the 3' end has a hydroxyl group. When writing DNA sequences, the convention is to start from the 5' end to the 3' end, which is crucial for accurately determining the complementary strand's sequence.

Antiparallel Structure of DNA

The two strands of DNA run in opposite directions, a feature known as antiparallelism. This means that if one strand runs from 5' to 3', the complementary strand runs from 3' to 5'. This structural characteristic is important for understanding how the strands interact and how replication and transcription processes occur.