Answer to Question #286427 in Organic Chemistry for Oliver

Question

3

rd diagram: Show how the lagging strand undergoes replication. Make sure to

show specific nucleotides (show at least 20 nucleotides on the parent of the

complementary lagging strand).

● Label the polarity of all strands.

● Indicate direction of replication fork and direction of lagging strand replication.

● Make sure to include one distinct Okazaki fragments and an additional two

Okazaki fragments about to be joined.

● On the two Okazaki fragments about to be joined, make sure to replace the RNA

primers of the 2nd fragment with the appropriate nucleotides. Illustrate the

enzyme responsible for this and the enzyme that joins the 2 fragments together.

● Include all other enzymes involved in the replication of this lagging strand. Make

sure to indicate in your drawing where the enzyme(s) would be working on the

DNA molecule.

Answer 1

The “lagging strand” is synthesized in the direction away from the replication fork and away from the DNA helicase unwinds. This lagging strand is synthesized in pieces because the DNA polymerase can only synthesize in the 5′ to 3′ direction, and so it constantly encounters the previously-synthesized new strand.