1. DNA Replication
CH 11 Section 3

2. The Template Mechanism
When new cells form  a complete set of genetic instructions is generated for each new cell
DNA copying involves a “template”
During DNA copying the two strands separate  each strand then acts as a template for producing a new complimentary strand
Nucleotides line up 1 at a time across from the existing strand using the base-pairing rules
Enzymes link the nucleotides together to form 2 new daughter DNA strands
This process is called DNA replication

3. During DNA replication, the two strands of the original parent DNA molecule, shown in blue, each serve as a template for making a new strand, shown in yellow. Replication results in two daughter DNA molecules, each consisting of one original strand and one new strand.

4. Replication of the Double Helix
Involves more than a dozen enzymes
Each “incoming” nucleotide pairs w/ its complementary nucleotide on the parent strand
DNA polymerases (enzymes): form covalent bonds to link nucleotides
FAST process & ACCURATE (~1 mistake in a billion nucleotides)
Process starts at “origins of replication” = many on one strand.
Increases speed of replication

5. DNA replication begins at origins of replication and proceeds in both directions, producing "bubbles." Eventually, all the bubbles merge, resulting in two separate daughter DNA molecules.

6. Concept Check 11.3 Describe how DNA replicates by using a template.
List the steps involved in DNA replication.
Under what circumstances is DNA replicated?