2.1 DNA replication terms Flashcards
DNA
Deoxyribonucleic acid, the molecule that carries genetic information.
Nucleotide
The building block of DNA, consisting of a sugar, a phosphate group, and a nitrogenous base.
Base Pairing
The specific pairing of nitrogenous bases in DNA: Adenine (A) with Thymine (T), and Cytosine (C) with Guanine (G).
Chromosome
A tightly coiled structure of DNA and proteins that contains genetic information.
DNA Replication
The process of copying a DNA molecule to produce two identical copies.
Helicase
An enzyme that unwinds the DNA double helix, separating the two strands.
Replication Fork
The Y-shaped region where the DNA double helix is unwound and replication occurs.
Topoisomerase
An enzyme that relieves the strain caused by unwinding the DNA helix.
Primase
An enzyme that adds short RNA primers to the DNA strands, providing a starting point for DNA polymerase.
DNA Polymerase III
The main enzyme responsible for adding nucleotides to the new DNA strand, building a complementary copy of the template strand.
Leading Strand
The strand of DNA that is synthesized continuously in the same direction as the replication fork.
Lagging Strand
The strand of DNA that is synthesized discontinuously in short fragments (Okazaki fragments) in the opposite direction of the replication fork.
Okazaki Fragments
Short fragments of DNA synthesized on the lagging strand.
DNA Polymerase I
An enzyme that replaces the RNA primers with DNA nucleotides.
Ligase
An enzyme that joins the Okazaki fragments together to form a continuous DNA strand.
Proofreading
The ability of DNA polymerase to correct errors during replication.
Mismatch Repair
A mechanism that corrects errors that were not caught during proofreading.
Mutation
A permanent change in the DNA sequence.
