Chapter 25 DNA replication

DNA Review DNA is a nucleic acid The components are Deoxyribose Phosphate Nitrogen Base The nitrogen bases are Guanine, Cytosine, Adenine, and Thymine The structure is... Double helix

DNA Replication DNA needs to be replicated so cells may divide 3 steps in replication Unwinding  The two strands that were held together by hydrogen bonds separate and the hydrogen bonds break. The Enzyme DNA Helicase “unzips” the DNA Complementary Base Pairing  nucleotides fit into place Joining  the complementary nucleotides join together to make new strands. They are joined with the enzyme DNA Polymerase

This is the Unwinding stage. DNA Helicase This is where the Nitrogen Base Pairs pair up with the old DNA DNA Polymerase combines the nucleotides and changes it into a new strand

This DNA replication is called Semiconservative because each new double helix has one old strand and one new strand DNA replication occurs in the nucleus and it needs to happen before cell division The old strand is called the parent strand The new strand is called the daughter strand

Recombinant DNA