DNA Replication

DNA Replication

• DNA: genetic material• Replication: copying of materials• DNA Replication: Copying of genetic material• All organisms undergo DNA replication

DNA Replication

Overview– Occurs during S phase of interphase– Double helix is unwound– Can predict the sequence of bases from original

strand– Each strand serves as a template for the new

strand– Double helix is reconnected

DNA Replication

• Enzyme breaks hydrogen bonds between bases– DNA Helicase– Unzips the Double Helix a little at a time– DNA bases are exposed

DNA Replication

• Free nucleotides attach to their base pair.– Free nucleotide: individual nucleotide floating in

cytoplasm– Occurs while DNA is being unzipped– Attach to bases via hydrogen bonds– DNA Polymerase: enzyme that bonds each

nucleotide into a chain.

DNA Replication

• Two new double helixes are formed– DNA continues to unzip until the entire molecule

is replicated.– Each new molecule contains one new strand and

one old strand of DNA– Identical from the original strand.