Enzymes in DNA Replication

Questions and Answers

What is the function of helicase?

Breaks or melts the hydrogen bonds that hold the two halves of the double helix together

What does topoisomerase do?

Breaks and reseals the DNA backbone to allow the backbone to release tension caused by twisting

What is the role of primase in DNA replication?

Also called RNA polymerase, puts down small pieces of RNA called primers.

What does DNA polymerase do?

Makes new strands of DNA Signup and view all the answers

What is the function of DNA polymerase III?

Copies DNA by reading the code on the existing strands and building new strands that are complementary to the original. Signup and view all the answers

What does DNA polymerase I do?

Removes RNA nucleotides from the RNA primers and replaces them with DNA nucleotides Signup and view all the answers

What is the role of DNA ligase?

Seals up breaks in the DNA backbone by forming covalent bonds between nucleotides Signup and view all the answers

Study Notes

Enzymes Involved in DNA Replication

Helicase: Unwinds DNA double helix by breaking hydrogen bonds between base pairs, essential for opening the DNA strands.
Topoisomerase: Relieves supercoiling and tension in the DNA helix by cutting and resealing the backbone, preventing tangling during replication.
Primase: Functions as RNA polymerase to synthesize short RNA primers, which provide starting points for DNA replication.
DNA Polymerase: Enzyme responsible for synthesizing new DNA strands by adding nucleotides complementary to the template strand; two types play distinct roles.
DNA Polymerase III: Primary enzyme in DNA replication; reads existing DNA strands to create new complementary strands according to base pairing rules.
DNA Polymerase I: Removes RNA primers and replaces them with DNA nucleotides, ensuring the final DNA molecule contains only DNA sequences.
DNA Ligase: Fills in gaps between adjacent nucleotides by forming covalent bonds, effectively sealing breaks and completing the DNA strand continuity.

Description

This quiz covers the key enzymes involved in DNA replication, including Helicase, Topoisomerase, Primase, and DNA Polymerases. Test your knowledge on how these enzymes function and their roles in the replication process. Understand the complexities of DNA mechanics and their significance in cell division.