DNA Replication

Question 1

What is DNA replication?

Answer 1

The process of copying DNA to ensure each new cell receives an identical copy of DNA during cellular division

Question 2

What is the role of helicase in DNA replication?

Answer 2

Uncoils and unzips DNA strands, creating a replication fork by breaking hydrogen bonds using ATP energy, operating in the 5’ to 3’ direction

Question 3

What is the role of primase in DNA replication?

Answer 3

Adds a short RNA primer at the start of the 5’ end of each DNA strand to initiate replication

Question 4

What does DNA polymerase III do on the leading strand?

Answer 4

Synthesizes complementary nucleotide bases continuously in the same direction as helicase, requiring only one primer

Question 5

How does DNA polymerase III function on the lagging strand?

Answer 5

Synthesizes short DNA fragments (Okazaki fragments) in the 5’ to 3’ direction, requiring multiple primers

Question 6

What is the function of exonuclease (DNA polymerase I)?

Answer 6

Removes uracil from primers and replaces it with thymine

Question 7

What role does DNA ligase play in DNA replication?

Answer 7

Seals the new DNA strand by forming the necessary covalent and hydrogen bonds

Question 8

What does “semi-conservative” DNA replication mean?

Answer 8

Each new DNA molecule contains one old strand and one newly synthesized complementary strand