Watch helicase unwind and DNA polymerase build new strands.
Helicase unwinds the double helix by breaking hydrogen bonds. DNA Polymerase III adds complementary nucleotides (A↔T, C↔G) to each template strand. The leading strand is synthesized continuously (3'→5'), while the lagging strand forms Okazaki fragments. Primase adds RNA primers; Ligase seals the fragments.