The name of the twisted ladder shape of the DNA molecule is called a double helix. This is because it is constructed of two long strands that twist around each other to form a ladder-like structure.
The double helix shape of DNA molecules consists of two rails and steps that link the rails together. DNA nucleotides line up so that the sugar and phosphate molecules create two long backbones, which form the rails of DNA's double helix structure. The steps of the structure are made of two bases that are joined together by either two or three weak hydrogen bonds. The two bases join together between each sugar molecule on the structure's backbones.