Replication Flashcards
When does DNA replication occur?
During the S phase
What is formed by DNA replication?
Identical sister chromatids and they go into the 2new cells’ nuclei
What are the stages of replication?
- DNA double helix unwinds and unzips from one end of the chromosome
- Hydrogen bonds between complementary base pairs to break to separate the two strands.
- ‘Free’ DNA nucleotides hydrogen bond by the base pairing rule onto the exposed complimentary bases of the original DNA on both strands.
- The sugar of one nucleotide and phosphate group of the next nucleotide are joined by phosphodiester bonds from a condensation reaction to form the sugar phosphate backbone
What is the enzyme involved in unzipping the DNA?
DNA helicase
What is the enzyme involved in the formation of the sugar phosphate backbone
DNA polymerase
What is attached to the 5’ end?
A phosphate group
What is attached to the 3’ end?
An OH group
What end does DNA polymerase bind to?
Only the OH on the 3’ end
What is the direction of DNA polymerase?
3’ to 5’
How does DNA polymerase work?
Both strands are copied at the same time and it travels in opposite directions of the 2 strands
What is the leading and lagging strands?
The 2 strands being copied in different directions
What are the 2 strands?
The leading and lagging strand
What is the leading strand?
The strand that is unzipped from the 3’ end
What are the 2 types of replication
Continuous and discontinuous
What kind of replication is on the leading strand?
Continuous