DNA Replication and Repair

These flashcards cover important terms and definitions related to the processes, mechanisms, and components of DNA replication and repair.

DNA Replication

The process by which a copy of DNA is made.

Base-Pairing

The complementary pairing of nucleotides in DNA strands, allowing each strand to serve as a template for replication.

Replication Origins

Specific locations on DNA where replication begins.

DNA Helicase

An enzyme that unwinds the double-stranded DNA at the replication fork.

Single-stranded DNA-binding proteins

Proteins that bind to single-stranded DNA to prevent it from reforming base pairs.

Sliding Clamp

A protein that encircles DNA and holds DNA polymerase in place during replication.

DNA Topoisomerases

Enzymes that relieve the tension in DNA ahead of the replication fork.

Deoxyribonucleoside triphosphates (dNTPs)

The building blocks of DNA, providing the energy for polymerization during replication.

Leading Strand

The continuously synthesized DNA strand during DNA replication.

Lagging Strand

The DNA strand synthesized discontinuously in short fragments known as Okazaki fragments.

DNA Polymerase

An enzyme responsible for adding nucleotides to a growing DNA strand and for proofreading.

Primase

An enzyme that synthesizes RNA primers for DNA replication.

DNA Ligase

An enzyme that seals gaps between Okazaki fragments during replication.

Telomeres

Non-coding 'caps' at the ends of chromosomes that protect genetic information.

Mutations

Alterations in the DNA structure that can produce permanent changes in genetic information.

Mismatch Repair (MMR)

A DNA repair mechanism that fixes errors missed during DNA replication.

Base Excision Repair (BER)

A repair mechanism that replaces altered bases in DNA.

Nucleotide Excision Repair (NER)

A mechanism that removes bulky DNA damage by cutting out a segment of DNA.

Homologous Recombination

A process that accurately repairs DNA double-strand breaks using a homologous DNA template.

Nonhomologous End Joining (NHEJ)

A repair process that ligates broken DNA ends together, which can result in mutations.