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