wk 10 assignment 3
Short fragments of DNA created on the lagging strand of DNA during replication are called
Okazaki fragments
The enzyme that relieves DNA supercoiling ahead of the replication fork is
DNA gyrase
The DNA controlled by an origin is called a____
replicon
When the double stranded DNA helix is unwound, two single strands of DNA are formed. These strands have to be stabilized because their hydrophobic bases are exposed to water. The proteins that stabilize the two single strands are called
single-strand binding proteins
The term_____ refers to the coiling of two DNA strands leading to torsional strain.
supercoiling
leading strand lagging strand
synthesized continuously synthesized in small fragments that are later connected
DNA replication in E. coli ends at a site called the_____
terminus
The enzymes in the replisome are active on
the leading and the lagging strands
The partial opening of a DNA helix to form two single strands is called
the replication fork
What class of enzymes relieve torsional strain in DNA strands ahead of the replication fork?
Topoisomerases
Bacterial replication (for example in E. coli) begins at
a single origin
The enzyme DNA______ is the topoisomerase involved in DNA replication.
gyrase
The enzyme_____ uses ATP to unwind the DNA template
helicase
The sliding clamp of a DNA polymerase
holds the polymerase to the DNA template
The topological state of DNA refers to
how the DNA coils
An Okazaki fragment is a short fragment of DNA created on the____ strand of DNA
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
As the lagging strand is being synthesized, adjacent Okazaki fragments are joined by the enzyme DNA
ligase
DNA primase (choose all that apply)
makes a primer about 10 -20 nucleotides in length. makes a primer of RNA complementary to the DNA.
The enzyme DNA_____ synthesizes the RNA primers required by DNA polymerases during replication.
primase
Which DNA polymerase removes and replaces RNA primer segments in the synthesis of the lagging stand because it has 5' to 3' exonuclease activity.
1
In prokaryotes, the two daughter molecules (each a double strand) produced at the end of replication are intertwined, similar to two links in a chain. What is the name of the enzyme that unlinks the two daughter DNA molecules?
Gyrase
In a bacterium, where does termination of replication occur, relative to the origin?
The termination site is opposite to the origin
Which subunit of DNA polymerase III forms the sliding clamp?
The β subunit
In E. coli, oriC is the site at which replication
begins
In the replisome, the______ is composed of primase, helicase, and accessory proteins that prime the lagging strand.
primosome
A ____ ____ is the partial opening of a DNA helix to form two single strands.
replication fork
helicase gyrase primase polymerase
unwinds the double helix relieves coiling in DNA strands ahead of the replication fork makes a 10-12 bp complementary primer to the DNA attaches a nucleotide to the 3' end of the DNA strand