DNA Replication /student/animations/dna_replication/in dex.html /student/animations/dna_replication/in dex.html

Structure of DNA Review

Antiparallel Nature of DNA

Complimentary Base Pairing

 DNA replication ensures the continuity of hereditary information.  Replication occurs as cells prepare to divide, during the S phase of interphase.  The replication process is semiconservative, where one strand serves as a template for a new, complimentary strand.  Replication requires many enzymes, occurs bidirectionally, and differs in production of the leading and lagging strands.  The result of DNA replication is 2 new strands of DNA, each with ½ old DNA and ½ new DNA. Continuity of Heredity Info

How does this diagram depict the semi- conservative nature of DNA replication? Semiconservative Replication

Origins of Replication

Replication Enzymes

Priming DNA Synthesis

Leading & Lagging Strand

1. DNA polymerase elongates DNA strands only in the 5’ → 3’ direction. 2. One new strand (leading strand) can therefore elongate continuously 5’ → 3’ as the replication for progresses. 3. The other new strand (lagging strand), must grow in an overall 3’ → 5’ direction by addition of short segments (Okazaki fragments) that grow 5’ → 3’ (numbered here in the order they were made). 4. Ligase connects the Okazaki fragments.