DNA replication

DNA replication

DNA replication creates exact copies of DNA within cells, the process can be carried out with very few errors. errors occur at a rate of 1 in 1000000000 bases per replication.

Key Enzymes

DNA Helicase - Unzips double stranded DNA by breaking hydrogen bonds between base pairs, to allow other enzymes to access bases.

DNA Primase - Catalyses the polymerisation of short RNA strands (primers) which act as a place for DNA Polymerase III to bind and start replication.

DNA Polymerase III - Attatches to primers on open DNA strands and builds a complementary strand, Working from the 5' to the 3' end.

DNA Polymerase I - Catalyses DNA replication and posesses a 3' to 5' exonuclease activity, which essentially "proof reads" the replication and lowers error rate.

DNA Ligase - Joins deoxyribose backbone in lagging strand.

References

http://bioteach.ubc.ca/TeachingResources/MolecularBiology/DNAReplication.swf

http://www.promega.com/products/cloning-and-dna-markers/cloning-tools-and-competent-cells/dna-polymerase-i/