BIOMOLECULES AND ENZYMES

Detailed explanation-1: -A phosphate backbone is the portion of the DNA double helix that provides structural support to the molecule. DNA consists of two strands that wind around each other like a twisted ladder. Each strand has a backbone made of alternating sugar (deoxyribose) and phosphate groups.

Detailed explanation-2: -The double helix looks like a twisted ladder-the rungs of the ladder are composed of pairs of nitrogenous bases (base pairs), and the sides of the ladder are made up of alternating sugar molecules and phosphate groups.

Detailed explanation-3: -The sugar-phosphate backbone forms the structural framework of nucleic acids, including DNA and RNA. This backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

Detailed explanation-4: -Sugar. Both DNA and RNA are built with a sugar backbone, but whereas the sugar in DNA is called deoxyribose (left in image), the sugar in RNA is called simply ribose (right in image).