Terms in this set (30)
Which term accurately describes the replication of DNA in vivo?
Which term accurately reflects nature of replication of the chromosome in E. Coli?
Bidirectional and fixed point of initiation
DNA polymerase III adds nucleotides
to the 3' end of the RNA primer
DNA polymerase I is thought to add nucleotides
in the place of the primer RNA after its removed
Structures located at the ends of eukaryotic chromosomes are called
Which cluster of terms accurately reflects nature of DNA replication in prokaryotes?
Fixed point of initiation, bidirectional, semiconservative
Discontinuous aspect of replication of DNA in vivo is caused by
5' to 3' polarity restriction
As unwinding of the helix occurs during DNA replication, tension is created ahead of the replication fork. Describe the nature of this tension and the manner it will be resolved.
Supercoiling; DNA gyrase
Complex of proteins that is involved in the replication of DNA is called
Which protein is responsible for the initial step in unwinding the DNA helix during replication of the bacterial chromosome?
What is the function of RNA primase during DNA replication?
Provides a free 3'-OH upon which DNA polymerization depends.
Compare the rate of DNA replication in prokaryotes and eukaryotes
Eukaryotic DNA polymerases synthesize DNA at a rate 25x slower than do prokaryotes.
What is the name of the replication unit in prokaryotes, and how does it differ in eukaryotes?
Replicon; one replicon in prokaryotes, multiple replicons in eukaryotes
What term is used to describe genetic exchange at equivalent positions along two chromosomes with substantial DNA sequence homology?
Describe the function of the RecA protein.
Promotes exchange of reciplrocal single-stranded DNA molecule by enhancing hydrogen bond formation during strand displacement.
What three possible models were suggested to orginally describe the nature of DNA?
Conservative, semiconservative, dispersive
Meselson and Stahl determined that DNA replication in E.Coli is semiconservative. What additive did they initially supply to the medium in order to distinguish "new and "old" DNA
DNA replication occurs in thr 5' to 3' direction, new nucleoside triphosphates are added to the 3' end
DNA repilcates conservatively, which means that one of the two daughter double helices is "old" and the other is "new"
DNA strand replication begins with an RNA primer
In general, DNA replicates semiconservatively and bidirectionally
In ligase-deficient strains of E.Coli, DNA and chromosomal replication are unaltered because ligase is not involved in DNA replication.
During replication, primase adds a DNA primer to RNA
In the Meselson and Stahl experiment, bean plants were radioactive labeled so that autoradiographs could be made of chromosomes
A nucleosome is a structure associated with the nuclear membrane. It helps maintain a stable relationship between the extracellular matrix and the membrane itself.
A characteristic of aging cells is that their telomeres become shorter
Telomerase is an RNA-containing enzyme that adds telomeric DNA sequences onto the ends of linear chromosomes
Bacteria are dependent on telomerase to complete synthesis of their chromosome ends.
Chromatin assembly factors move along with the replication fork and assemble new nucleosomes
G-quartets are G-rich single-stranded tails that loop back on themselves forming G-G double-stranded sections. Such looping is involved in aligning chromosomes for homologous recombination.