If the structure of DNA were likened to a ladder what would make up the supporting structure (not the rungs) of a ladder?

If the structure of DNA is likened to a ladder, the supporting structure would be the sugar-phosphate backbone. This backbone consists of alternating sugar (deoxyribose) and phosphate groups that provide structural support to the DNA molecule, holding the rungs (the nitrogenous base pairs) together. Just like the sides of a ladder, the sugar-phosphate backbone maintains the integrity and stability of the DNA double helix.