Ch6

Helicase

Unwinds DNA to begin replication.

Gyrase

Relieves tension during unwinding.

Primase

Adds RNA primers at the start of the new strand (5’ end).

Pol III

Adds remaining nucleotides to the unwinding double helix.

Leading Strand

Moves towards the replication fork; DNA synthesis is continuous.

Lagging Strand

Moves away from the replication fork; DNA synthesis is fragmented (discontinuous).

Okazaki fragments

Little fragments on the lagging strand after RNA primers are removed.

DNA Ligase

Fills in the gaps to link Okazaki fragments together.

DNA Polymerase I and III

Proofread for accuracy during replication.

Nucleotide

Consists of phosphate group, five-carbon sugar, and nitrogen-containing base.

Watson and Crick

Discovered DNA's double helix structure.

Chargaff's rule

A=T, C=G in base pairing.

Semiconservative Replication

One old strand remains in the new DNA.

Single-strand binding proteins (SSBP)

Prevent strand reunion during replication.

Griffith, Hershey, Chase, Franklin, Watson, and Crick

Key figures in DNA discovery.