Dna Replication

Question 1

Outline the initiation step of dna replication

Answer 1

DNA helically nreaks the hydrogen bonds between dna strands.

• this causes DNA to unzip.
• from this you get a replication fork ,

Question 2

Outline the elongation step of dna replication

Answer 2

• the enzyme DNA primase synthesises a DNA primer for DNA polymerase to to use as a starter to start laying down new nucleotides.
• DNA polymerase extends this RNA primer at the 3’ end.
• leading strand is made continuously whereas the lagging strand is made in pieces called Okazaki fragments.

Question 3

Outline the termination step of DNA replication

Answer 3

• the process of expanding new DNA strands continues until there is no more DNA template to replicate or two replication forks meet.
• RNAase H removes the RNA primer that is at the beginning of each Okazaki fragment and DNA Ligase joins two fragments together creating one complete strand.

Question 4

In what direction is DNA read?

Answer 4

3 to 5’

Question 5

In what direction is DNA synthesised ?

Answer 5

5’ to 3’