DNA replication Flashcards
When does DNA replication occur?
Occurs before cells divide (by mitosis or meiosis)
Why does DNA replication occur?
DNA replication occurs to provide a copy for the new cell
How does DNA replication occur? What is it called?
DNA replication is semi conservative replication. In the daughter DNA one strand is from the parental DNA and one strand strand is newly synthesised
What is daughter DNA?
The DNA that is created in the human body
What is parental DNA?
The original DNA that is going to be copied
What breaks the hydrogen bonds between the complementary base pairs between the two strands within a double helix?
DNA helicase
What is the first step of semi conservative replication?
DNA helicase breaks the hydrogen bonds between the complementary base pairs between the two strands within a double helix
What does the breaking of hydrogen bonds cause the double helix to do?
The breaking of the hydrogen bonds between the complementary base pairs causes the DNA double helix to unwind
What is the second step of semi conservative replication?
- Each of the separated parental DNA strand will act as a template
- Then free floating DNA nucleotides within the nucleus attracted to their complementary base pairs on the template strands of the parental DNA
After the first step of semi conservative replication, what role do each of the separated parental DNA strands have
Each of the separated parental DNA strands acts as templates
In step two, are the DNA nucleotides that are attracted to their complementary base pairs bonded yet?
No, they are still monomers and a polynucleotide chain has not been formed yet
What is the third step of semi conservative replication?
The adjacent nucleotides are joined together by a condensation reaction, to form the phosphodiester bond
DNA polymerase catalyses the joining together of the adjacent molecules
What is the function of DNA polymerase?
DNA polymerase catalyses the joining together of adjacent molecules
What is the fourth step of semi conservative replication?
The two sets of daughter DNA contains one strand of parental DNA and one newly synthesised strand
What is the complete process of semi conservative replication?
- DNA helix add breaks the hydrogen bonds between bases to unwind the double helix
- Free floating DNA nucleotides in the nucleus then align with their exposed complementary bases along the template strands
- DNA polymerase joins together the adjacent nucleotides to make the new strand via condensation reactions
- The two new sets of daughter DNA contain one strand of parental DNA and a newly synthesised strand of DNA
