Topic C Flashcards
Template strand
In DNA replication, the parental strand whose sequence is used to synthesize a complementary daughter strand
Daughter strand
In DNA replication, the strand synthesized from a parental template strand
Semi conservative replication
The mechanism of DNA replication in which each strand of a parental DNA duplex serves as a template for the synthesis of a new daughter strand
Replication fork
The site where the parental DNA strand separate as the DNA duplex unwinds
DNA grows in a
5’ 3’ direction
DNA polymerization
occurs only in the 5’ 3’ direction
DNA polymerase
An enzyme that is a critical component of a large protein complex that carries out DNA replication
Leading strand
A daughter strand that has its 3’ end pointed toward the replication form, so as the parental double helix unwinds, this daughter strand can be synthesized as one long, continuous polymer
Lagging strand
A daughter strand that has its 5’ end pointed towards the replication fork, so as the parental double helix unwinds, a new DNA piece is initiated at intervals, and each new piece is elongated at its 3’ end until it reaches the piece in front of it
Okazaki fragments
In DNA replication any of the many short DNA pieces in the lagging strand
RNA primase
An RNA polymerase that synthesizes a short piece of RNA complementary to the DNA template and does not require a primer
DNA Ligase
An enzyme that uses the energy in ATP to close a nice in a DNA strand, jointing the 3’ hydroxyl of one end to the 5’ phosphate of the other end
Topoisomerase II
An enzyme that breaks a DNA double helix, rotates the ends, and seals the break
Helicase
A protein that unwinds the parental double helix at the replication fork
Single stranded binding protein
A protein that binds single stranded nucleic acids
Proofreading
The process in which DNA polymerase can immediately correct their own errors by excising and replacing a mismatched base
Origin of replication
Any point on a DNA molecule at which DNA synthesis is initiated
Replication bubble
A region formed by the opening of a DNA duplex at an origin of replication, which has a replication fork at each end.
Telomeres
A repeating sequence at each end of a eukaryote chromosome
Telomerase
An enzyme containing an RNA template from which complementary telomere repeats are synthesized
Germ cells
The reproductive cells that produce Sperm or eggs and the cells that give rise to them
Stem cell
An undifferentiated cell that can undergo an unlimited number of mitotic divisions and differentiate into any of a large number of specialized cell types
Polymerase chain reaction (PCR)
A selective and highly sensitive method for making copies of a piece of DNA, which allows a targeted region of a DNA molecule to be replicated into as many copies as desired
Oligonucleotide
A short (typically 20 to 30 nucleotides) single stranded molecule of known sequence produced by chemical synthesis, oligonucleotides are often used as primer sequences in the polymerase chain reaction
Denaturation
The unfolding of proteins by chemical treatment or high temperature; the separation of paired, complementary strands of nucleus acid
Annealing
The coming together of complementary strands of single stranded nucleic acids by base pairing
Extension (PCR)
A step in the polymerase chain reaction for producing new DNA fragments in which the reaction mixture is heated to the optimal temperature for DNA polymerase and each primer is elongated by means of deoxynucleoside triphosphates
