Chapter 8 Lesson 2 Flashcards
What is a leading strand?
The parent strand that runs in the 3’ to 5’ direction continously
What is a lagging strand?
The parent strand that runs in the 5’ to 3’ direction discontinously
What does it mean to be semi-discontinous?
The leading strand moves constantly through the DNA replication process, while the lagging strands go in chunks, so that is discontinuous
What is semi-conservative replication?
Where each of the two daughter molecules will have one old strand front of the parent molecule and one newly-made strand
What are Okazaki fragments?
The little fragments from the lagging strand
What is the function of helicase?
Unwind the DNA molecule
What is the function of primase?
Add RNA primers
What is the function of DNA polymerase III?
Add new nucleotides to build a complimentary strand
What is the function of DNA polymerase I?
Replace RNA primers with DNA nucleotides
What is the function of ligase?
Join remaining fragments together to make a continuous strand
What are the order of events in DNA replication?
- Helicase
- Primase
- DNA polymerase III
- DNA polymerase I
- Ligase
What did Meselson and Stahl’s experiment do?
They were trying to find out what type of replication DNA uses
What did Meselson and Stahl’s experiment find out?
DNA uses semi-conservative replication
How can we identify leading and lagging strands on a replication fork?
The strand going from 3’ -> 5’ is the leading strand and the strand going from 5’ -> 3’ is the lagging strand
Where are the Okazaki fragments on a DNA replication fork?
On the lagging strand, all of the separate little parts
Where are the 3’ ends on a DNA replication fork?
The 3’ end is the one that the DNA strands travel into
Where are the 5’ ends on a DNA replication fork?
The 5’ end is the one that the DNA strands start from
