Unit 4 DNA

4.1.4 DNA replication reading

Before a cell can replicate it must make an identical copy of its DNA so that the new cell has all the genetic information. The DNA helix is unwound and unzipped by the enzyme helicase that breaks the hydrogen bonds between the paired bases at the replication fork. The two single strands act as a template as complementary nucleotides are placed in the right order because of the base pairing rules. The enzyme DNA polymerase joins the new nucleotides together to make a new DNA strand. The two resulting DNA molecules each contain one new strand and one old strand of DNA. This is called semi-conservative replication.

DNA replication split by Madeleine Price Ball / CC BY-SA 3.0

Go on to section 4.1.5 for a presentation on DNA replication.

Sources:

Life Science, CK12 Flexbook http://cafreetextbooks.ck12.org/science/CK12_Life_Science.pdf