DNA Replication

Question 1

Steps of DNA Replication

Answer 1

1. DNA Helicase unzips the 2 strands by breaking the hydrogen bonds holding the base pairs together.

(After splitting the base pairs are again activated through attraction so SSB (Single-Stranded Binding) Proteins bind to the DNA strands to keep them separated.

2. DNA Primase shows where to start the building of the new strand for DNA Polymerase. By making RNA primers.
3. DNA Polymerase builds the new strand using old strands as a template + free nucleotides. (DNA Polymerase can only build in the 5’ to 3’ direction)
4. So DNA Ligase goes back to the lagging strand to fill in the gaps of the DNA strand, left by DNA Polymerase

Question 2

DNA Helicase Role

Answer 2

Unzips the strand of DNA into two identical strands, need as a reference to make new strands.

Question 3

DNA Primase Role

Answer 3

To place RNA primers at the origin points on the separate DNA strands for DNA Polymerase to know where to start.

Question 4

DNA Polymerase

Answer 4

Builds the new strands of DNA from the old strands as a reference and builds off of them. though it only does this in the 5’ to 3’ direction, leaving gaps on the second DNA strand known as the lagging strand for its empty lagged patches in between.

Question 5

DNA Ligase

Answer 5

Fills in the missing patches left behind by DNA Polymerase as it had to go back and continue building, so DNA Ligase fills in the empty spots.