DNA
Structure and Replication
Concept 2: DNA Double Helix
DNA consists of two polynucleotide
chains wound around each other to form a double helix.
![](images/dnaspace.gif)
The helix twists in the
right-handed direction—think of two strands of rope twisted around
each other in the clockwise direction. This twisting is an inherent
property of DNA, and it is the same when the helix is looked at from
either end.
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