DNA Structure and PCR

DNA (deoxyribonucleic acid) appears as a long narrow string- shaped segment of genes in human body. The DNA structure is referred to as a double helix, which forms through binding of two strands of nucleic acid molecules. Though the bonds are weak, the two strands are intertwined into long segments, which make them difficult to separate. However, DNA melting enzymes, called helicases, help in unwinding the strands so that sequence reading enzymes, such as DNA polymerase, can function on them.