DNA Replication Lecture

Vocabulary terms summarizing the cellular process, enzymes, and structural components involved in DNA replication as described in the lecture.

DNA Replication

The process that involves the creation of two new strands of DNA from one, occurring during the S-phase of the Cell Cycle.

Semi-conservative model

A replication process where each new DNA molecule contains one parental DNA strand (conserved) and one new DNA strand.

Initiation

The first stage of DNA replication where DNA Helicases unzip or unwind the DNA helix.

DNA Helicases

Enzymes that unzip or unwind DNA by moving along the molecule to create replication forks.

Replication forks

The regions at which the DNA helix is unwound and the direction in which DNA Helicase is moving.

Elongation

The stage of replication where RNA Primase forms a primer and DNA Polymerase adds nucleotides to the unzipped strands.

RNA Primase

An enzyme that forms a primer, which is a short strand of RNA complementary to the DNA template, to begin elongation.

Primer

A short strand of RNA consisting of a few nucleotides that are complementary to the DNA template.

DNA Polymerase

An enzyme that adds free nucleotides to unzipped strands in the $5'$ to $3'$ direction and proofreads the new strands for errors.

Antiparallel

The orientation of the two strands in a DNA molecule where each strand runs opposite to the other, from $5'$ to $3'$ and $3'$ to $5'$.

Leading Strand

The parental strand where replication occurs continuously in the same direction as the replication fork and the movement of Helicase.

Lagging Strand

The parental strand where elongation occurs in the opposite direction of the replication fork, requiring multiple RNA primers.

Okazaki Fragments

Short fragments or sections of nucleotides built on the lagging strand in the $5'$ to $3'$ direction.

DNA Ligase

An enzyme that binds Okazaki Fragments together to form a continuous strand on the lagging strand of DNA.

Termination

The final stage of DNA replication where the new molecules are twisted into a double helix and DNA Polymerase proofreads and corrects errors.