DNA replication Flashcards
(11 cards)
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 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
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 function of DNA polymerase?
DNA polymerase catalyses the joining together of adjacent nucleotides
What is the complete process of semi conservative replication? (4)
- DNA helicase breaks the hydrogen bonds between the complementary base pairs within the double helix
- The exposed parental strands act as template strands attracting free DNA nucleotides towards their complementary base pairs
- DNA polymerase catalyses the condensation reaction joining adjacent nucleotides with the formation fo a phosphodiester bond and the removal of a water molecule
- At the end of the reaction, two sets of daughter DNA forms. One with the parental DNA strand and one newly synthesised
