The pentose sugar in dna is ribose. hydrogen bonds formed between the sugar‑phosphate backbones of the two dna chains to stabilize dna structure. the nucleic acid strands in a dna molecule are oriented antiparallel to each other, meaning they run in opposite directions. nucleic acids are formed through phosphodiester bonds that link nucleosides together.

Question missing:

Which of the following statements about DNA structure is true?

The nucleic acid strands in a DNA molecule are oriented antiparallel to each other, meaning they run in opposite directions.

Explanation:

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 simulating the steps of a staircase; the pairs are joined together by hydrogen bonds. The two strands of the helix run in opposite directions, so that the 5′ carbon end of one strand faces the 3′ carbon end of its matching strand. This antiparallel orientation is important to DNA replication and in many nucleic acid interactions.

DNA is a Double Helix Native DNA is an antiparallel double helix. The phosphate backbone (indicated by the curvy lines) is on the outside, and the bases are on the inside. Each base from one strand interacts via hydrogen bonding with a base from the opposing strand.

The hydrogen bonding between the complementary bases also sequester the bases in the interior of the double helix. Therefore, the hydrogen bonding between the bases reinforces the hydrophobic effects that stabilize the DNA.