D1.1 - DNA Replication Flashcards
What does semi-conservative DNA replication mean?
Each newly synthesized double-stranded DNA molecule contains one original strand and one newly synthesized strand.
How does DNA synthesis occur on the leading strand?
DNA polymerase III synthesizes DNA continuously in the 5’ to 3’ direction.
What is the role of helicase in DNA replication?
Helicase breaks the hydrogen bonds between base pairs, unzipping the DNA molecule.
What do single strand binding proteins (SSBPs) do?
They prevent single strands from re-annealing and protect them from degradation.
What was the Meselson-Stahl experiment?
An experiment that demonstrated the semi-conservative nature of DNA replication using heavy and light nitrogen.
What is the role of DNA Polymerase III?
It is the primary enzyme responsible for adding nucleotides to the growing DNA strand.
What is the function of DNA gyrase?
It relieves the tension caused by unwinding the DNA, preventing tangling.
What enzyme is used in PCR?
Taq DNA polymerase, isolated from Thermus aquaticus.
Why do eukaryotic chromosomes require special mechanisms for replication?
Because they are linear, requiring mechanisms to replicate the ends (telomeres).
What are Okazaki fragments?
Short segments of DNA synthesized on the lagging strand during replication.
What is the Polymerase Chain Reaction (PCR)?
A biotechnology technique that rapidly produces multiple copies of a specific DNA sequence.
What were the results of the Meselson-Stahl experiment after one generation?
All DNA molecules had intermediate density (one heavy strand, one light strand).
What is the outcome of repeating the PCR steps multiple times?
It exponentially increases the amount of target DNA.
What is DNA replication?
A fundamental biological process that ensures the accurate transmission of genetic information from one generation to the next.
What is a key difference between prokaryotic and eukaryotic DNA replication?
Prokaryotes have a single origin of replication, while eukaryotes have multiple origins.
