8.2 Flashcards
What is the leading strand?
The strand that has nucleotides added to it going towards helicase in a continuous manner.
What is the lagging strand?
The strand that has nucleotides added to it going away from helicase in a discontinuous manner.
What does semi-discontinuous mean?
Part of the process is continuous and part is discontinuous. This is how DNA is replicated.
What is semiconservative replication?
The original strand is halved and each part is added to.
What are Okazaki fragments?
Parts that are added to the lagging strand in a discontinuous manner.
What does helicase do?
Unzips the strands.
What does DNA Polymerase III do?
Adds DNA nucleotides to make complimentary strands.
What does DNA Polymerase I do?
Removes RNA primers and replaces them with DNA.
What does Ligase do?
Joins the fragments of DNA.
What does Primase do?
Adds RNA primers to the DNA.
What are the order of events in DNA replication?
Helicase unzips the DNA strands, RNA Primer is placed by Primase, DNA nucleotides are added by DNA Polymerase III, RNA Primer is replaced by DNA by Polymerase I, Okazaki fragments are glued together by Ligase.
What was Meselson and Stahl’s experiment?
Set up different ways DNA replication could happen with lighter and heavier strands and then mix them up so some floats to the top and sinks to the bottom, then see what matches with the actual tube.
What did Meselson and Stahl find out?
DNA is replicated in a semi-conservative manner.
What direction are nucleotides added?
5’ to 3’
What is the purpose of DNA replication?
To create identical copies of DNA.
What are the parental strands?
The original strands of DNA.
What does Ligase join together?
Sugar to Phosphate.
What functional group is attached to 3’?
Hydroxyl.
What functional group is attached to 5’?
Phosphate.
What bond does helicase break?
Hydrogen.
