Final answer:
DNA replication is the process where DNA is copied, involving enzymes such as helicase to unzip the DNA and DNA polymerase to add complementary nucleotides and proofread the new strands. The process is semi-conservative, resulting in two DNA molecules, each with an old and a new strand.
Step-by-step explanation:
The process of copying a DNA molecule, known as DNA replication, involves several key steps and enzymes. Firstly, the enzyme helicase unwinds the DNA double helix by breaking the hydrogen bonds between nucleotide pairs. This exposes the individual strands to act as templates for the synthesis of new DNA strands.
During DNA polymerase's action, complementary nucleotides are added to each template strand; this enzyme forms phosphodiester linkages, building the new strand in a 5' to 3' direction. The leading strand is synthesized continuously, while the lagging strand is synthesized in short stretches called Okazaki fragments, which are later joined together by the enzyme DNA ligase.
After the completion of synthesis, DNA polymerase proofreads each DNA molecule to correct any errors, contributing to the high-fidelity of replication. The two new DNA double helices, each consisting of one old and one new strand, coil back into their typical helix structure, and are ready to be passed on to daughter cells when the cell divides.