DNA replication

DNA replication is the basis of biological inheritance and it is a fundamental process that occur in every living organisms. In replication, each strand of original double-stranded DNA serves as template for the reproduction of the the complementary strand. Therefore, following DNA replication, two identical DNA molecules have been produced from a single double-stranded DNA molecule.

DNA replication inside the cell begins at a specific location called 'origins'. Unwinding of DNA at the origin, and synthesis of new strands, forms a replication fork. In addition to DNA polymerase, the enzyme that synthesizes the new DNA by adding nucleotides that matched to the template strand, a number of other proteins are associated with the fork and assist in the initiation and continuation of DNA synthesis.  Whereas for DNA replication that perform replication outside the cell, DNA polymerase isolated from cells and artificial primers are used to initiate the DNA synthesis at known sequences in a template molecule. The polymerase chain reaction (PCR), a common laboratory technique, employs such artificial synthesis in a cyclic manner to amplify a specific target DNA fragment from a pool of DNA.