StellarNucleic Acids
Nucleic acids have a defined directionality based on the linear sequence of nucleotides, with specific ends marked by the 3’ hydroxyl group and the 5’ phosphate group of the sugar in each nucleotide. During DNA and RNA synthesis, nucleotides are added to the 3’ end of the growing strand, forming covalent bonds that link the nucleotides together. DNA is organized into an antiparallel double helix, where the two strands run in opposite 5’ to 3’ orientations. Base pairing is specific: adenine pairs with thymine via two hydrogen bonds, while cytosine pairs with guanine via three hydrogen bonds, ensuring stable and accurate genetic encoding.