DNA Replication Quiz (DOK 1)

What is the function of DNA Helicase?

• Unzips” the strand of DNA

  Breaks the hydrogen bonds so that new nucleotides can be added

• Bind to separated strands of DNA to keep the strands separate

• Creates a strand of RNA nucleotides

  DNA nucleotides must be added to something. Primase creates a strand of nucleotides that DNA Polymerase I can add nucleotides to. It is not in the final product.

• Removes/replaces the RNA primer. Proofreads new DNA strand.

What is the function of single stranded binding proteins?

• Unzips” the strand of DNA

  Breaks the hydrogen bonds so that new nucleotides can be added

• Bind to separated strands of DNA to keep the strands separate

• Creates a strand of RNA nucleotides

  DNA nucleotides must be added to something. Primase creates a strand of nucleotides that DNA Polymerase I can add nucleotides to. It is not in the final product.

• Removes/replaces the RNA primer. Proofreads new DNA strand.

What is the function of DNA Primase?

• Unzips” the strand of DNA

  Breaks the hydrogen bonds so that new nucleotides can be added

• Bind to separated strands of DNA to keep the strands separate

• Creates a strand of RNA nucleotides

  DNA nucleotides must be added to something. Primase creates a strand of nucleotides that DNA Polymerase I can add nucleotides to. It is not in the final product.

• Removes/replaces the RNA primer. Proofreads new DNA strand.

What is the function of DNA Polymerase I?

• Unzips” the strand of DNA

  Breaks the hydrogen bonds so that new nucleotides can be added

• Bind to separated strands of DNA to keep the strands separate

• Creates a strand of RNA nucleotides

  DNA nucleotides must be added to something. Primase creates a strand of nucleotides that DNA Polymerase I can add nucleotides to. It is not in the final product.

• Removes/replaces the RNA primer. Proofreads new DNA strand.

What is the function of DNA Polymerase III?

• Removes/replaces the RNA primer. Proofreads new DNA strand.

• Adds nucleotides to RNA primer, thus synthesizing a new strand of DNA. Has a “proofreading” role.

• Relaxes DNA from super coil so it can be replicated.

• Joins fragments of DNA together.

What is the function of topoisomerase?

• Removes/replaces the RNA primer. Proofreads new DNA strand.

• Adds nucleotides to RNA primer, thus synthesizing a new strand of DNA. Has a “proofreading” role.

• Relaxes DNA from super coil so it can be replicated.

• Joins fragments of DNA together.

What is the function of DNA Ligase?

• Removes/replaces the RNA primer. Proofreads new DNA strand.

• Adds nucleotides to RNA primer, thus synthesizing a new strand of DNA. Has a “proofreading” role.

• Relaxes DNA from super coil so it can be replicated.

• Joins fragments of DNA together.

Place the steps of DNA replication in order.

• The double helix unwinds using DNA helicases

• Enzymes known as DNA polymerases move along each of the DNA strands

  Add nucleotides to the exposed nitrogen bases forming two new strands of DNA

• The process continues until all of the DNA has been copied and the polymerases are signaled to detach

What is the end result of DNA replication?

• Two identical DNA molecules each composed of one new and one original strand

• Two non-identical DNA molecules each composed of one new and one original strand

• Two identical DNA molecules. One is made up of the two old strands and one is made up of the two new strands.

• Two non-identical DNA molecules. One is made up of the two old strands and one is made up of the two new strands.

DNA replication starts at one end and ends at the other.

• True

• False