Chapter 11 - DNA Replication Flashcards
What do we call the two new made DNA strands?
We call them daughter strands
What are the three different models of DNA replication?
- conservative model
- semiconservative model
- dispersive model.
What is the conservative model?
Both the parental strands stay together after DNA replication.
What is the semiconservative model?
The double stranded DNA contain one parental strand and one daughter strand.
What is the dispersive model?
Parental and daughter strands are interspersed in both strands following the DNA replication.
Who are the scientist that were able to distinguish between the parental and the daughter strands?
Mathew Mealson and Franklin stahl.
Where does the DNA synthesis begin?
It begin at the origin of replication.
What is the origin of replication for E coli?
It is oriC
What are the three important DNA sequence in oriC?
- DNA boxes: It is the site where DNA A protein bind
- A-T rich region: sites where the DNA strands separate
- GATC methylation sites: sites that help regulate DNA replication
What is the functionality of DNA a protein?
It helps with addition to other proteins to bend the DNA molecule. It causes the region to wrap around the DNA a protein and separate the A-T rich region.
What is the function of DNA helicase?
It separate he DNA strands in both direction. ( breaks the hydrogen bonds between strands)
What is the function of Topoisomerase II ( DNA gyrase)?
It alleviates positive supercoiling.
What is the function of single stranded binding protein?
It keeps the parental strands apart.
What is the function of primase?
It synthesizes an RNA primer.
What is the function of DNA polymerase III?
It synthesizes a daughter strand of DNA.
What is the function of DNA polymerase?
It excises the RNA primers and fill in with DNA..
What is the function of DNA ligase?
It covalently links the backbone of DNA in the okazaki fragments.
What is DNA polymerase III composed of?
It is composed of 10 different subunits.
What is the function of alpha Subunit?
It catalyzed bond formation between adjacent nucleotides.
What is DNA polymerase I composed of?
It is composed of single polypeptide.
What is the function of Beta subunit?
It holds the DNA polymerase III from falling off the template.
What is exonuclease?
It digest the newly synthesized strand until the mismatched nucleotide is removed. it works from 3 to 5.
Where are the termination sequence located?
They are located at the opposite side of oriC
What happen when Tus bind to Ter?
It stops the movement of the replication fork.
