BCHM3050 Chapter 20: DNA Replication and Repair

These flashcards cover key terminology and concepts related to DNA replication and repair, as discussed in the lecture.

Prokaryotes

Organisms with genomes consisting of millions of base pairs; characterized by the absence of a nucleus.

Eukaryotes

Organisms with genomes consisting of billions of base pairs; contain a defined nucleus.

Semiconservative replication

Each replicated DNA molecule consists of one 'old' strand and one 'new' strand.

Conservative replication

Two newly synthesized DNA strands come together while the original helix is conserved.

Dispersive replication

Parental DNA strands are dispersed into two new double helices.

Meselson-Stahl Experiment

An experiment that demonstrated semiconservative replication of DNA using E. coli and nitrogen isotopes.

Nucleotides

Building blocks of DNA, consisting of a nitrogenous base, a sugar, and a phosphate group.

Theta replication

Type of DNA replication in circular DNA, involving a single origin of replication forming a bidirectional replication fork.

Rolling-circle replication

A form of replication that begins with a break in one of the nucleotide strands, producing circular and linear DNA.

Okazaki fragments

Short DNA fragments formed during the discontinuous synthesis of the lagging strand during DNA replication.

DNA polymerase

Enzyme that catalyzes the synthesis of DNA; requires a template and dNTPs.

Proofreading activity

The ability of DNA polymerase to remove incorrect nucleotides during DNA replication.

Telomeres

Inert chromosomal ends that protect eukaryotic chromosomes from fusion and degradation.

Telomerase

An enzyme that adds repeating sequences to the ends of chromosomes to maintain telomere length.

Nucleosomes

Structural units of eukaryotic chromatin, consisting of DNA wrapped around histone proteins.