Consider the sequence 3'-ACGCTACGTC-5'.

What is the double-stranded sequence?

Key Concepts

DNA Structure

DNA is composed of two strands that form a double helix, with each strand consisting of nucleotides. Each nucleotide contains a phosphate group, a sugar, and a nitrogenous base (adenine, thymine, cytosine, or guanine). The strands are antiparallel, meaning they run in opposite directions, which is crucial for base pairing.

Base Pairing Rules

In DNA, specific base pairing occurs between nucleotides: adenine pairs with thymine (A-T) and cytosine pairs with guanine (C-G). This complementary base pairing is essential for the accurate replication and transcription of genetic information, ensuring that the genetic code is preserved.

Antiparallel Orientation

The antiparallel orientation of DNA strands means that one strand runs in the 5' to 3' direction while the complementary strand runs in the 3' to 5' direction. This orientation is important for the mechanisms of DNA replication and transcription, as enzymes that synthesize DNA and RNA can only add nucleotides to the 3' end of a growing strand.