DNA Replication Flashcards
What is the sugar attached to on the 3’ end of DNA?
The hydroxyl group
What is the sugar attached to on the 5’ end of DNA?
A phosphate group
What is the model for DNA replication known as?
Semiconservative model
What does helicase do?
Unzips the DNA strands
What does topoisomerase do?
Removes supercoiling ahead of helicase
What is DNA Polymerase III?
Synthesizes DNA in the leading and lagging strands
What does primase do?
Lays down a short piece of RNA primer
What does DNA Polymerase do?
Removes RNA primer and fills in gaps with DNA
What do single stranded binding proteins do?
binds to single stranded DNA
and prevents it from re-forming a double stranded structure
What side of the DNA strand DNA polymerase add nucleotides to?
The 3’ Side
What is a leading strand?
A daughter strand that is made continuously
What is a lagging strand?
A daughter strand made in Okazaki fragments
In what direction do daughter strands grow?
5’-3’
What enzyme glues Okazaki fragments together?
DNA ligase
What are the two types of DNA mutations?
Miss ese and frameshift
What is a missense mutation?
One base is switched, resulting in a new protein
What is a frameshift mutation?
Alters the reading frame of the sequence through insertion or deletion
What is a telomere?
Telomeres are the caps at the end of each strand of DNA that protect our chromosomes, like the plastic tips at the end of shoelaces.
What happens to telomeres each time a cell copies itself?
They get shorter each time
What happens when telomeres get too short to do their job?
cells start to age and stop functioning properly
What type of DNA has no histones?
Bacterial DNA
