Session Overview
This session will explain how DNA is replicated prior to cell division. In this process, DNA polymerase uses an original strand as a template to create a new daughter strand of DNA. Polymerization occurs in the 5' to 3' direction, creating a new strand that is anti-parallel to the original. Polymerization begins at a specific DNA sequence called the Origin of Replication and proceeds in two directions along both template strands. Because of the directionality of synthesis, one strand is synthesized continuously, while the other strand is synthesized in small fragments, which are then joined together by DNA ligase. Learning Objectives
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Session Activities
Lecture Video
Watch the lecture video excerpt
- DNA Replication (00:33:42)
Check Yourself
Below is a representation of an origin of replication and the two associated replication forks. Synthesis of new DNA occurs on both strands.
Session Activities
Help Session Video
Watch the short video of Sera Thornton explaining the numbering and labeling conventions of RNA and of proteins.
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Explanation of 5' and 3', C terminus, and N terminus (00:02:08)
Explanation of 5' and 3', C terminus, and N terminus
> Download from iTunes U (MP4 - 4.7MB)
> Download from Internet Archive (MP4 - 4.7MB)
Practice Problems
Further Study
Suggested topics for further study in an introductory-level Biology textbook
- DNA Replication
Useful Links
- Replication: Mechanism of Replication (Basic), 3-D Animation Library
- Replication: Mechanism of Replication (Advanced), 3-D Animation Library