Which statement BEST describes why the sugar phosphate nucleic acid backbone is on the outer part of the DNA double helix while the nitrogen bases are on the inside of the double helix?
A) The sugar phosphate backbone is hydrophilic while the bases are less polar.
B) The sugar phosphate backbone is hydrophobic while the bases are hydrophilic.
C) The sugar phosphate backbones of the two strands are bonded together.
D) The nitrogen bases are covalently bonded to each other.
E) There is no reason; the structure is just that way.

Question

Quizplus · Accepted Answer

The sugar phosphate backbone is hydrophilic, meaning it interacts favorably with water, which is why it is on the outer part of the DNA double helix. The nitrogen bases are less polar and more hydrophobic compared to the backbone, so they are located on the inside where they can participate in hydrogen bonding with complementary bases from the opposite strand, away from the aqueous environment.

Which Statement BEST Describes Why the Sugar Phosphate Nucleic Acid