DNA replication

Question 1

what is semi-conservative

Answer 1

-when DNA is copies in the 2 new strand of dna there is:
-half the origional DNA template which is conserved
-the other half of the DNA is new copied DNA

Question 2

why and when does the cell copy the DNA

Answer 2

-during the S-phase between G1 and G2
-DNA undergos semi-conservative replication

Question 3

step one to 4 of the DNA replication process

Answer 3

1) helicase enzyme moves between strands unzipping them
2) DNA polymerase binds to the 3’ end of the DNA on leading strand
3)binds where there is RNA primer
4) DNA polymerase moves along strand, gathering free nucleotides in complementary base pairs

Question 4

what is the name for when
DNA is replicated on the leading strand

Answer 4

-Continuous replication as it can move along without stopping

Question 5

what must be remembered about DNA polymerase

Answer 5

-can only bind to the 3’ (phosphate/ OH) end so has to bind to primer

Question 6

step 5-9 of DNA replication

Answer 6

5) on lagging strand, RNA primers are placed at different points
6) signals DNA polymerase where to attatch
7) creates Okazaki fragments
8) fragments joined by enzyme ligase forming phosphodiester bonds between them
9) DNA polymerase replicates the RNA primers with DNA nucleotides which are also joined by ligase

Question 7

last step of DNA replication

Answer 7

-2 new strands of replicated, semi-conservative DNA