Final answer:
The DNA double helix structure is held together by hydrogen bonds between nitrogenous bases. These base pairs are adenine with thymine and guanine with cytosine, essential for the DNA's function in storing genetic information.
Step-by-step explanation:
DNA Structure and Hydrogen Bonding
The two strands of the DNA double helix are held together by hydrogen bonds between pairs of nitrogenous bases. These base pairs are always adenine with thymine (A-T) and guanine with cytosine (C-G), which form the steps of the spiral stair ladder-like structure of the DNA molecule.
The combination of a phosphate group, a five-carbon sugar (deoxyribose), and a nitrogen-containing base make up the nucleotide units that bond together to form each strand of DNA, while the hydrogen bonds between these nucleotides' bases keep the two strands connected, making DNA a highly charged and stable molecule vital for storing genetic information.
Several key features of the DNA structure include its double helical shape, the antiparallel direction of the strands, and the nitrogen base pairing that works like a zip, allowing DNA to carry the genetic code specific to each living organism. These hydrogen bonds between nitrogenous bases are critical to the function of DNA, as they allow for the DNA molecule to unzip for replication and protein synthesis, while also providing stability to the overall structure.