How do nucleotides connect to form a nucleic acid strand?

Nucleotides connect to form a nucleic acid strand primarily through covalent bonds, specifically phosphodiester bonds. These bonds occur between the phosphate group of one nucleotide and the ribose sugar of the adjacent nucleotide, creating a backbone of alternating sugar and phosphate groups. This covalent linkage is crucial as it provides the structural integrity of the nucleic acid strand, allowing it to maintain its shape and stability during processes like replication and transcription.

While hydrogen bonds play a significant role between the base pairs in the double helix structure of DNA, they are responsible for the interactions between complementary bases rather than linking the nucleotides in a strand. Ionic bonds and Van der Waals interactions are also not involved in the primary connection of nucleotides within the nucleic acid structure. Thus, the formation of a nucleic acid strand is fundamentally based on these covalent phosphodiester linkages, which establish a stable framework for the nucleic acid.