Central dogma of molecular biology: DNA replication

Question 1

What phase of the cell cycle does DNA replication/DNA synthesis take place?

Answer 1

s phase

Question 2

What is the difference between the leading strand and the lagging strand?

Answer 2

the leading strand is replicated continuously whereas the lagging strand is replicated discontinuously

Question 3

Describe the process of DNA replication

Answer 3

1. Helicase unwind the parental double helix
2. single-strand binding proteins stabilize the unwound parental DNA
3. the leading strand is synthesised continuously in the 5’ - 3’ direction by DNA polymerase
4. the lagging strand is synthesised discontinuously. Primase synthesises a short RNA primer, which is extended by DNA polymerase to form an Okazaki fragment
5. After the RNA primer is replaced by DNA (by another DNA polymerase), DNA ligase joins the okazaki fragment to the growing strand.