Semi conservative replicationLeading & lagging strands

Question 1

DNA polymerase can only build the new strand in one direction ?

Answer 1

5’ to 3’ direction)

Question 2

as DNA is ‘unzipped’ from the 3’ towards the 5’ end, DNA polymerase will attach to the ..’ end of the original strand and move towards the replication fork(what is this

Answer 2

3

(the point at which the DNA molecule is splitting into two template strands)

Question 3

This means the DNA polymerase enzyme can synthesise the leading strand

Answer 3

continously

Question 4

This template strand that the DNA polymerase attaches to is known as the

Answer 4

leading

Question 5

The other template strand created during DNA replication is known as the

Answer 5

lagging strand

Question 6

On this strand, DNA polymerase moves away from the replication fork

Answer 6

(from the 5’ end to the 3’ end

Question 7

This means the DNA polymerase enzyme can only synthesise the lagging DNA strand in

Answer 7

short segments (called Okazaki fragments)

Question 8

A second enzyme known as DNA ligase is needed to

Answer 8

join these lagging strand segments together to form a continuous complementary DNA strand

Question 9

how does DNA ligase A second enzyme known as DNA ligase is needed to join these lagging strand segments together to form a continuous complementary DNA strand

Answer 9

DNA ligase does this by catalysing the formation of phosphodiester bonds between the segments to create a continuous sugar-phosphate backbone