BIOMOLECULES AND ENZYMES

Detailed explanation-1: -DNA has a double-helix structure, with sugar and phosphate on the outside of the helix, forming the sugar-phosphate backbone of the DNA. The nitrogenous bases are stacked in the interior in pairs, like the steps of a staircase; the pairs are bound to each other by hydrogen bonds.

Detailed explanation-2: -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-3: -These bonds are called phosphodiester bonds, and the sugar-phosphate backbone is described as extending, or growing, in the 5’ to 3’ direction when the molecule is synthesized.

Detailed explanation-4: -The sugar-phosphate backbones of the DNA strands make up the outside of the helix, while the nitrogenous bases are found on the inside and form hydrogen-bonded pairs that hold the DNA strands together.