DNA Replication (3.1.5.2) Flashcards
Part of Nucleic Acids Are Important Information-Carrying Molecules (3.1.5)
1
Q
When does DNA replication occur?
A
- During the process of cell division and has an important role in the growth and reproduction of organisms
2
Q
What is meant by semi-conservative replication?
A
- In the daughter DNA, one strand is from the parental DNA and one strand is newly synthesised
3
Q
What are the steps for DNA replication?
A
- DNA helicase breaks the hydrogen bonds between the complementary base pairs, causing the double helix to unwind and the two strands to separate
- These two separate strands both act as templates for DNA replication
- Free floating DNA nucleotides within the nucleus align and attach by hydrogen bonding to the exposed bases of each template strand following specific complementary base pairing rules
- Adenine pairs with thymine and cytosine pairs with guanine
- DNA polymerase catalyses the formation of phosphodiester bonds between adjacent nucleotides, joining them together in condensation reactions to form the sugar-phosphate backbone of the new strand
- The two DNA molecules are identical to each other and to the original DNA, each containing one strand of the parental DNA and one strand that is newly synthesised
4
Q
Who were the scientists who proposed models of the chemical structure of DNA and of DNA replication?
A
- Watson and Crick
