11. DNA Replication Flashcards
the process in which original DNA strands are used as templates for the synthesis of new DNA strands.
DNA Replication
a strand of DNA that is used to synthesize a complementary strand of DNA or RNA.
Template (Parental) Strand
in DNA replication, the two newly made strands of DNA.
Daughter Strands
an incorrect model of DNA replication in which both parental strands of DNA remain together following DNA replication.
Conservative Model
the correct model for DNA replication in which the newly made double-stranded DNA contains one parental strand and one daughter strand.
Semiconservative Model
an incorrect model for DNA replication in which segments of parental DNA and newly made DNA are interspersed in both strands following the replication process.
Dispersive Model
a site on a chromosome that functions as an initiation site for the assembly of several proteins that begin the process of DNA replication.
Origin of Replication
the manner in which two replication forks move, in opposite directions outward from the origin
Bidirectional
the region in which two DNA strands have separated and new strands are being synthesized.
Replication Fork
a protein that binds to a DnaA box sequence at the origin of replication in bacteria and initiates DNA replication.
DnaA Protein
a DNA sequence that serves as a recognition site for the binding of a DnaA protein, which is involved in the initiation of bacterial DNA replication.
DnaA Box
an enzyme that separates the two strands of DNA.
DNA Helicase
the phenomenon in which two DNA replication forks emanate in opposite directions from an origin of replication.
Bidirectional Replication
an enzyme that introduces negative supercoils into DNA using energy from ATP and that can also relax positive supercoils when they occur.
DNA Gyrase (Topoisomerase II)
proteins that bind to both of the single strands of DNA during DNA replication and prevent them from re-forming a double helix.
Single-Strand Binding Proteins
a short strand of RNA, made by primase, that is used to elongate a strand of DNA during DNA replication.
RNA Primer
an enzyme that synthesizes short RNA primers during DNA replication.
Primase
a strand during DNA replication that is synthesized continuously toward the replication fork.
Leading Strand
a strand during DNA replication that is synthesized as short Okazaki fragments in the direction away from the replication fork.
Lagging Strand
an enzyme that catalyzes the covalent attachment of nucleotides to form a strand of DNA.
DNA Polymerase
short segments of DNA that are synthesized to produce the lagging strand during DNA replication.
Okazaki Fragments
an enzyme that catalyzes the formation of a covalent bond within the sugar-phosphate backbones of two DNA strands.
DNA Ligase
a protein complex that includes DNA helicase and primase.
Primosome
a complex that contains a primosome and dimeric DNA polymerase.
Replisome
a complex of two DNA polymerase holoenzymes that move as a unit during DNA replication.
Dimeric DNA Polymerase
in E. coli, a pair of sequences in the chromosome that bind a protein known as the termination utilization substance (Tus), which stops the movement of the replication forks.
Termination Sequences (Ter Sequences)
intertwined circular molecules.
Catenanes
a mutant whose phenotype depends on the environmental conditions, such as a temperature-sensitive (ts) mutant.
Conditional Mutant
a mutant that has a normal phenotype at a permissive temperature but a different phenotype, such as failure to grow, at a nonpermissive temperature.
Temperature-Sensitive (ts) Mutant
an enzyme, such as RNA or DNA polymerase, which glides along the template strand and does not dissociate from it while catalyzing the covalent attachment of nucleotides.
Processive Enzyme
a term used to describe the accuracy of a process.
Fidelity
the ability of DNA polymerase to remove mismatched bases from a newly made strand.
Proofreading Function
DNA sequences found in yeast that function as origins of replication.
Automatic Replicating Sequence (ARS) Elements
in eukaryotes, an assembly of at least 14 different proteins, including a group of proteins called the origin recognition complex (ORC), which acts as the first initiator of preRC assembly.
Prereplication Complex (preRC)
a group of proteins found in eukaryotes that acts as the first initiator of preRC assembly to begin DNA replication.
Origin Recognition Complex (ORC)
a group of six proteins needed to complete a process called DNA replication licensing, which is necessary for the formation of two replication forks at an origin of replication in eukaryotes.
MCM Helicase
in eukaryotes, occurs when MCM helicase is bound at an origin of replication, enabling the formation of two replication forks.
DNA Replication Licensing
an exchange of one type of DNA polymerase for another type during DNA replication.
Polymerase Switch
a type of DNA polymerase that can replicate over a DNA region that contains an abnormal structure (i.e., a lesion).
Translesion-Replicating Polymerase
an enzyme that removes small RNA flaps that are generated by the action of DNA polymerase δ. It removes RNA primers during DNA replication.
Flap Endonuclease
specialized repeated sequences found at the ends of eukaryotic chromosomes.
Telomeres
the enzyme that recognizes telomeric sequences at the ends of eukaryotic chromosomes and synthesizes additional repeats of those telomeric sequences.
Telomerase
the RNA component of telomerase.
TERC
the enzyme within telomerase that uses RNA as a template to make DNA.
Telomerase Reverse Transcriptase (TERT)
describes a cell that is no longer capable of dividing.
Senescent
