Package 18
Which enzyme catalyzes the formation of covalent bonds between adjacent Okazaki fragments to complete the replication process?
Ligase
During DNA replication, the lagging strand is synthesized as a series of small fragments called----fragments
Okazaki
conservative mechanism
One new double-stranded DNA molecule contains two parental strands while the other molecule contains two daughter strands
Telomerase is made up of which of the following? Select all that apply.
Protein RNA
The Meselson and Stahl experiments supported this method of replication.
Semiconservative
There are relatively few errors during DNA replication due to the proofreading mechanisms by
DNA polymerase
In the late 1950s, three different models were proposed for the process of DNA replication. These were the --- mechanism, --- mechanism, and ---mechanism.
semiconservative, conservative, dispersive
leading strand
synthesized continuously
lagging strand
synthesized in small fragments that are later connected
The enzyme ---attaches DNA sequences at the ends of eukaryotic chromosomes.
telomerase
This enzyme prevents chromosomal shortening by attaching a repeat sequence to the ends of chromosome
telomerase
This is a region at the ends of eukaryotic chromosomes.
telomere
The RNA portion of telomerase is ---to the DNA repeat sequence.
complementary
All models of DNA replication include
daughter strands. parental strands.
Free nucleotides with three phosphate groups are called
deoxynucleoside triphosphate
The term high --- refers to a process that occurs with relatively few mistakes.
fidelity
Energy is generated to covalently connect adjacent molecules by breaking the bond between the---
first and second phosphates in the dNTP
A telomere
has a 3' overhang
In human cancer cells, telomerase is present in what level as compared to normal cell?
higher
In DNA replication, the ______ strand is made discontinuously in the direction opposite to the movement of the replication fork.
lagging
During DNA replication, the ---- strand is synthesized continuously while the ---- strand is synthesized as small fragments that are connected to each other to form a continuous strand.
leading lagging
The --- of replication is a site within a chromosome where DNA replication begins.
origin
During DNA replication, new strands are synthesized from --- strands on the original molecule.
parental
DNA template strands are referred to as ______ strands, while the newly synthesized strands are referred to as ______ strands.
parental; daughter
The enzyme ---- DNA covalently links nucleotides to synthesize new DNA strands together during DNA replication.
polymerase
What DNA enzyme covalently links nucleotides together?
polymerase
In order to start DNA synthesis on a bare template, this enzyme is needed
primase
Place the steps of semiconservative DNA replication in proper order. Start with the first step on top.
1. The Double helix separates 2. Nucleotides hydrogen bond to the template strand 3. covalent bonds form between sugars and phosphate 4. daughter strands are produced for each template strand.
The following represent steps in the process of DNA replication by telomerase. Arrange them in the right order, with the first step on top. Position 1 of 5 Telomerase binds to a DNA repeat sequence correct toggle button unavailable
1. telomerase bind to DNA repeat sequence 2. telomerase synthesis a 6-nucleotide repeat sequence 3.Telomerase moves six nucleotide to the night and begins to make a mother repeat 4. Primase make an RND... 5.DNA polymerase ...
In order to complete synthesis of the Okazaki fragments on the lagging strand, the following must occur. Place these items in the correct order. Start with the earliest on top.
1. the removal of RNA primers 2. The synthesis of DNA in the area where the primers have been removed 3. the covalent joining of adjacent fragment of DNA
During DNA replication, how many strands of DNA are used as templates to synthesize new strands?
2
The enzyme DNA polymerase attaches a nucleotide to the ______ end of a growing strand via a ______ bond.
3' ; phosphoester
Once synthesis has begun, DNA can only be synthesized in this direction
5' to 3'
The sequence repeated in human telomeres is
5'-GGGTTA-3'
Once replication has begun, new ---- can only be synthesized in a 5' to 3' direction.
DNA
This process occurs near the opening of replication forks
DNA replication
An origin of replication is a site within a chromosome where
DNA replication begins
The DNA polymerase that removes RNA primers and fills in the regions between fragments is
I
Semiconservative mechanism
The two new double-stranded DNA molecules each contains one parental strand and one daughter strand
Dispersive mechanism
The two new double-stranded DNA molecules each contains segments of parental and daughter DNA interspersed in both strands
During DNA replication, the lagging strand of DNA is synthesized in a 5' to 3' direction as DNA polymerase moves ______ the replication fork.
away from
DNA replication is described as ______ because DNA replication proceeds outward from two replication forks.
bidirectional
Telomerase function is associated with
cancer
An RNA --- is required to produce each Okazaki fragment in Escherichia coli.
primer
DNA polymerase can detect a mismatched nucleotide and remove it from the daughter strand. It does so by digesting the linkages in the 3' to 5' direction to remove the incorrect base and then changing direction to synthesize again in the 5' to 3' direction. This process is called
proofreading
DNA replication occurs near the opening that forms each
replication fork