DNA Replication and Repair

These flashcards cover key vocabulary and concepts related to DNA replication and repair, focusing on definitions and processes essential for understanding the material.

Semiconservative Replication

A process of DNA replication in which half of the parent structure is retained in each of the daughter duplexes.

Dispersive Replication

A model of DNA replication where parental strands are broken into fragments, and new strands are synthesized in short segments.

Conservative Replication

A model of DNA replication where the two original DNA strands remain together after serving as templates, resulting in one duplex with only parental DNA and another with only newly synthesized DNA.

Leading Strand

The newly synthesized DNA strand that grows toward the direction of the replication fork and is synthesized continuously.

Lagging Strand

The newly synthesized DNA strand that grows away from the replication fork and is synthesized discontinuously in small fragments called Okazaki fragments.

Okazaki Fragments

Short fragments synthesized on the lagging strand during DNA replication, which are later linked into a continuous strand by DNA ligase.

RNA Primers

Short strands of RNA that are required to initiate DNA synthesis by providing a starting point for DNA polymerase.

Primase

An enzyme that synthesizes a short primer composed of RNA to initiate DNA replication.

DNA Ligase

An enzyme that links the Okazaki fragments into a continuous strand during DNA replication.

Nucleotide Excision Repair

A DNA repair process that removes bulky lesions, such as pyrimidine dimers, using a cut-and-patch mechanism.

Base Excision Repair

A DNA repair mechanism that removes altered nucleotides generated by reactive chemicals.

Mismatch Repair

A DNA repair system that corrects mistakes made during DNA replication that escape the proofreading activity of DNA polymerases.

Nonhomologous End Joining (NHEJ)

A pathway for repairing double-strand breaks in DNA that is not a faithful repair, often resulting in loss of nucleotides.

Homologous Recombination (HR)

A more accurate pathway for repairing double-strand breaks in DNA, which requires an identical or similar template.