BioCoach Activity

Concept 5: Replicating Antiparallel DNA Strands

The two DNA strands are antiparallel, yet DNA polymerase can only synthesize new DNA in the 5' to 3' direction. This poses special problems for replicating double-stranded DNA.

The double-stranded DNA shown above is unwinding and ready for replication. Note the antiparallel nature of the strands; that is, the 5' to 3' orientation of the top strand and the 3' to 5' orientation of the complementary bottom strand.