DNA Replication Process and Key Components
The process of DNA replication begins when cells need to divide, ensuring each new cell receives a complete copy of genetic material. The replication process follows several distinct steps, each catalyzed by specific enzymes.
Definition: DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule.
Highlight: The process is semiconservative, meaning each new DNA molecule contains one original parent strand and one newly synthesized strand.
Vocabulary:
- Helicase: Enzyme that breaks hydrogen bonds between DNA strands
- Primase: Enzyme that adds RNA primers
- DNA Polymerase: Enzyme that adds new DNA nucleotides
- Ligase: Enzyme that joins DNA fragments together
The replication process involves four main steps:
- Helicase unzips the DNA double helix
- Primase adds RNA primers to initiate replication
- DNA Polymerase adds nucleotides in the 5' to 3' direction
- Ligase seals gaps in the sugar-phosphate backbone
Example: On the lagging strand, DNA is synthesized in short segments called Okazaki fragments because DNA polymerase can only work in the 5' to 3' direction.
Quote: "RNA Primers are removed and replaced with DNA nucleotides" to complete the replication process.