DNA Replication Flashcards
When does DNA need to make copies of itself?
Any time new cells are needed:
* Growth and development
* Repairing injury or fighting disease
* Making reproductive gametes
Is it important that DNA copies are exactly accurate?
Yes, it is important because cells must have the same blueprint; however, there are rare exceptions due to mutations.
What does it mean for base pairs to be complementary?
A is complementary to T, and G is complementary to C.
What enzyme unwinds the DNA double helix?
Helicase
What is the function of helicase in DNA replication?
It unwinds the double helix by breaking the hydrogen bonds between the complementary bases.
What are replication forks and bubbles?
Locations along the strand where unzipping occurs.
What enzyme adds new nucleotides during DNA replication?
DNA polymerase
In which direction does DNA polymerase add nucleotides?
5’-3’ direction
What forms on the lagging strand during DNA replication?
Okazaki fragments
How is DNA written on the lagging strand?
DNA is ‘backstitched’ in short fragments in the 5’ to 3’ direction.
What is the role of DNA ligase in DNA replication?
It bonds the Okazaki fragments.
What serves as a template for the new DNA strand?
Each parent strand
What is semi-conservative replication?
In each new double helix, one strand is old (‘conserved’) and one is new (‘semi’).
Fill in the blank: DNA must be written from the _______ end to the _______ end.
5’, 3’
True or False: Each DNA molecule produced is an exact copy of the other.
True
