DNA controls all cellular activity. It has the "recipe" for the functioning of a cell. Every time a cell divides, the "recipe" must be passed to the daughter cells.
The entire "file" containing information about cell functioning needs to be duplicated so that each child cell receives the same kind of information as the parent cell. For this to happen, it is critical that the DNA suffers “self-duplication”.
The structural DNA model proposed by Watson and Crick explains the duplication of genes: the two strands of DNA separate and each directs the manufacture of a complementary half.
Research by Meselson and Stahl confirmed that DNA duplication is semiconservative, that is, that half of the original molecule remains intact in each of the two daughter molecules.
In the process of DNA duplication, the hydrogen bridges between the bases break and the two chains begin to separate. As the bases are exposed, nucleotides that roam around them will join, always respecting the specificity of pairing: A with T, T with A, C with G and G with C. Once ordered on the As the strand being modeled, the nucleotides link in sequence and form a complementary strand over each of the original molecule's cadences. Thus, a DNA molecule reproduces two identical molecules to it.
The action of DNA polymerase enzyme
Several aspects of DNA duplication have already been unraveled by scientists. Today, it is known that there are several enzymes involved in this process. Certain enzymes unpair the two strands of DNA, opening the molecule. Others unroll the double helix, and there are those that unite the nucleotides with each other. The enzyme that promotes nucleotide binding is known as DNA polymerase, because its function is to build a polymer (from the Greek poly, many, and mere, part) of nucleotides.