DNA Replication Process and Historical Discovery

The process of DNA replication is fundamental to cell division and genetic inheritance. During this process, the original DNA molecule serves as a template for creating two identical copies.

Definition: Semi-conservative replication refers to the process where each new DNA double helix contains one strand from the original molecule and one newly synthesized strand.

Highlight: The role of DNA helicase in replication is crucial as it unwinds the double helix and breaks the hydrogen bonds between DNA strands, allowing replication to begin.

Example: The Meselson and Stahl DNA experiment demonstrated semi-conservative replication using different nitrogen isotopes (N-14 and N-15) to track original and newly synthesized DNA strands.

Vocabulary: Phosphodiester bonds - Chemical bonds that join nucleotides together in the DNA backbone.

The replication process involves several key steps:

1. DNA helicase unwinds the double helix
2. Free nucleotides are attracted to exposed bases on template strands
3. DNA polymerase catalyzes the formation of phosphodiester bonds
4. Complementary base pairing ensures accurate replication

Quote: "DNA has to replicate itself every time a cell divides" - This ensures that both daughter cells receive identical copies of the entire genome.