DNA Replication (E. coli)

What problems does DNA structure cause for its own replication? DNA is a stable molecule composed of two linear chains. These chains are attached to one another through hydrogen bonds between complimentary bases. The double chain then forms a helical coil. The bonding between the chains and the coil keep the base sequence stable and allow the DNA molecule to replicate itself. However, replication requires the uncoiling and separation of the two strands in the region where new DNA is being actively synthesized. A series of molecules are required to separate the strands and stabilize the coils in addition to DNA polymerase and the associated molecules that make new DNA.

View the animation below, then complete the quiz to test your knowledge of the concept.


1	Which of the following prevents supercoiling of the DNA strands ahead of the replication bubble?

		A)	helicase
		B)	topoisomerase
		C)	DNA binding proteins
		D)	DnaA
		E)	all of the above

2	Which of the following molecules initiates the formation of the replication bubble?

		A)	helicase
		B)	DNA polymerase
		C)	DnaA
		D)	topoisomerase
		E)	DNA primase

3	Which of the following synthesizes the daughter strands during DNA replication?

		A)	DNA primase
		B)	helicase
		C)	RNA polymerase
		D)	DNA polymerase
		E)	topoisomerase

4	Synthesis of the daughter DNA strand from the leading strand template occurs in a 5’ to 3’ direction.

		A)	True
		B)	False

5	Okazaki fragments are involved in the replication of the leading strand in a replication bubble.

		A)	True
		B)	False

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