chapter 3 Flashcards
When the DNA molecule becomes untwisted and the two strands separated, each strand could act as a template for the synthesis of anew complementary strand is known as _______ because each progeny molecule retains one of the parental strands.
semiconservative model
When the two parental strands of DNA remain together or part again after replication and, as a whole, serve as a template for the synthesis of a new progeny DNA double helices. One of the two progeny dna molecules is the prental double-stranded dna molecule and the other consists entirely of new material.
conservative model
When the parental double helix is cleaved into double-sttranded DNA segments that act as templates for the synthesis of new double-stranded DNA segments. the segments reassemble into complete dna double helices, with parental and progeny dna segments interspersed.
dispersive model
In 1958 they obtained experimental evidence that the semiconservative replication model is correct. By growing E. coli in which the only nitrogen source was ammonium chloride. NH4Cl
Matthew Meselson and Frank Stahl
In 1955 he was the first to identify the enzymes necessary for DNA replication.
Arthur Kornberg
dATP, dGTP, dTTP, dCTP are collectively known as dNTP which stands for
deoxyribonucleoside triphosphate
enzymes that catalyze DNA synthesis are called
DNA polymerases.
For DNA to be synthesized in vitro 5 components are required.1.______2._______3.________4.________5._________
All four dNTP’S , DNA POL I, E. coli DNA, DNA to act as a primer, and magnesium ions.
how many dna polymerases are there?
5 pol I and Pol III are necessary for replication , and Pol I, II, IV, and V are involved in DNA repair.
DNA synthesis begins at the ______ prime end of a template strand and moves downward using the DNA polymerase
3
how many phosphate groups are removed after a base pair has been assembled?
2
the DNA polymerase acts as a ________ when attaching the phosphate groups to each other
catalyst
When the DNA polymerase corrects the sequence on a nucleotide it is known as ______ and what is the name of the polymerase?
proofreading, exonuclease
The initiation of DNA replication is directed by a sequence called
replicator
usually includes the replicator, the specific region where the DNA double helix denatures into single strands and within which replication commences.
origin of replication
segments of single strands in the replication bubble on which the new strands are made are called
template strands
When DNA untwists to expose the two single stranded template strands for DNA replication , a Y shaped structure is formed called a
replication fork
when DNA is being synthesized and the helicase is splitting the double helix the strand that moves in the direction of splitting is called
the leading strand
when DNA is being synthesized and the helicase is splitting the double helix the strand that moves in the opposite direction of splitting is called _______ and they form ________ fragments.
the lagging strand. OKAZAKI
The process of separation of double-stranded DNA to two single strands is called DNA ________ or DNA______
denaturation, melting
SSB what is it?
Single-strand DNA-binding proteins bind to each single stranded dna stabilizing them
Each RNA primer is extended by the addition of DNA nucleotides by which polymerase?
Pol III
Because the leading strand is synthesized continuously, whereas the lagging strand is synthesized in pieces, discontinuously, DNA replication as a whole occurs in a ________
semidiscontinuous manner
what joins two Okazaki fragments together when DNA replication is done?
Pol I, and DNA ligase
