DNA Replication: Process, Enzymes, and Cell Cycle in Biology

What are the three essential properties of DNA?

1) It must contain stable information encoding proteins, 2) it must replicate accurately, 3) it must allow for variation (mutation).

During which phase of the cell cycle does DNA replication occur?

During the S (synthesis) phase of Interphase.

What is the process of cell division called?

Mitosis.

What are the stages of Mitosis?

Prophase, Metaphase, Anaphase, Telophase.

What is cytokinesis?

The division of the cytoplasm after mitosis.

What theory of DNA replication was proven by Meselson and Stahl?

The Semi-Conservative model of DNA replication.

What forms as the DNA strands open during replication?

Replication bubbles.

How many replication bubbles do prokaryotes have?

A single replication bubble.

How many replication bubbles do eukaryotic chromosomes have?

Many replication bubbles.

What enzyme unzips the DNA molecule during replication?

DNA helicase.

What role do Single Stranded Binding proteins (SSBPs) play in DNA replication?

They keep the strands stable during replication.

In which direction must DNA replication occur?

In a 5' to 3' direction.

What is the leading strand in DNA replication?

The strand that is copied continuously.

What is the lagging strand in DNA replication?

The strand that is copied discontinuously in short segments.

What is the function of Primase in DNA replication?

To lay down RNA primers needed for DNA polymerase to build off.

What are Okazaki fragments?

Short stretches of DNA synthesized between RNA primers on the lagging strand.

What enzyme removes RNA primers during DNA replication?

Exonuclease.

What enzyme fills in gaps left by removed RNA primers?

DNA polymerase.

What enzyme joins DNA fragments together?

DNA ligase.

What is the initial error rate of DNA polymerase during replication?

About 1 in every 10,000 base pairing errors.

What is the error rate of DNA after proofreading?

1 in 1 billion base pairing errors.