Enzymes in DNA Replication Flashcards

Questions and Answers

What is DNA helicase?

Known as the helix destabilizing enzyme that unwinds the DNA double helix at the replication fork.

What is the function of DNA polymerase?

Builds a new duplex DNA strand by adding nucleotides in the 5' to 3' direction and performs proof-reading and error correction.

What does topoisomerase do?

Relaxes the DNA from its super-coiled nature.

What is the role of primase in DNA replication?

Provides a starting point of RNA (or DNA) for DNA polymerase to begin synthesis of the new DNA strand. Signup and view all the answers

What is the function of the DNA clamp?

A protein that prevents DNA polymerase III from dissociating from the DNA parent strand. Signup and view all the answers

What does DNA gyrase relieve?

Strain of unwinding by DNA helicase; it is a specific type of topoisomerase. Signup and view all the answers

What is the function of DNA ligase?

Re-anneals the semi-conservative strands and joins Okazaki fragments of the lagging strand. Signup and view all the answers

What does telomerase do?

Lengthens telomeric DNA by adding repetitive nucleotide sequences to the ends of eukaryotic chromosomes. Signup and view all the answers

Study Notes

Enzymes in DNA Replication

DNA Helicase:
- Functions as a helix destabilizing enzyme.
- Unwinds the DNA double helix at the replication fork, allowing access for other enzymes.
DNA Polymerase:
- Synthesizes a new DNA strand by adding nucleotides in a 5' to 3' direction.
- Engages in proofreading and error correction to maintain DNA integrity.
Topoisomerase:
- Relieves the super-coiled tension in DNA during replication, facilitating smoother unwinding.
Primase:
- Synthesizes a short RNA (or DNA) primer providing a starting point for DNA polymerase to initiate new strand synthesis.
DNA Clamp:
- Functions as a protein that stabilizes DNA polymerase III, preventing it from disassociating from the DNA parent strand during replication.
DNA Gyrase:
- A specialized form of topoisomerase that alleviates the strain caused by the unwinding action of DNA helicase.
DNA Ligase:
- Joins Okazaki fragments on the lagging strand by re-annealing the semi-conservative strands, ensuring continuous DNA synthesis.
Telomerase:
- Adds repetitive nucleotide sequences to the ends of eukaryotic chromosomes, lengthening telomeric DNA to protect chromosomal integrity during cell division.

Description

Explore essential enzymes involved in DNA replication with these flashcards. Learn about the roles of DNA Helicase, DNA Polymerase, and Topoisomerase in the process of unwinding and synthesizing DNA strands. Ideal for students looking to reinforce their understanding of molecular biology.