DNA Replication Overview

What is the role of topoisomerase in DNA replication?

Which statement accurately describes the leading strand during DNA replication?

What is the function of DNA ligase in the context of DNA replication?

Which enzyme is responsible for unwinding the DNA strands to form the replication fork?

In which direction does DNA Polymerase add nucleotides during DNA replication?

DNA Replication Overview

DNA replication is the process of copying a chromosome (supercoiled DNA) to produce two identical DNA molecules.
This is essential for cell division to ensure that each new daughter cell receives the same genetic information as the parent cell.
The original DNA helix is called the parent DNA and each strand serves as a template for a new strand.

DNA Replication Steps

Topoisomerase: An enzyme that loosens supercoiled DNA ahead of replication fork to allow access for enzymes.
Helicase: An enzyme that unzips and separates the DNA by breaking the hydrogen bonds between nitrogenous bases, forming a Y-shaped structure called the replication fork.
DNA Polymerase: The enzyme responsible for adding nucleotides one by one to the new growing complementary strand. It moves along the parent template strand in the 3' to 5' direction and can only add nucleotides to the 3' end of the new strand.
- Leading strand: Made continuously in the same direction as replication fork.
- Lagging strand: Made in small pieces (Okazaki fragments) in the opposite direction of the replication fork.
DNA Ligase: An enzyme that connects the gaps between the Okazaki fragments on the lagging strand.

This quiz explores the intricate process of DNA replication, which is vital for cellular division. It covers the roles of key enzymes such as topoisomerase, helicase, and DNA polymerase in ensuring accurate copying of genetic information. Test your knowledge on the mechanisms involved in creating identical DNA molecules.