Nucleotides
By Etash Jayaprakash
Nucleotides are the simple units that build DNA (Deoxyribonucleic Acid) and RNA (Ribonucleic Acid). They are made up of 3 parts, the pentose sugar, the phosphate and the base, connected by strong covalent bonds. Each nucleotide connects to each other through weak hydrogen bonds.
The most important part about nucleotides in DNA and RNA is the base, as that is what does the encoding. There are 4 bases: Adenine, Thymine, Guanine, and Cytosine. These are noted as A, T, G and C respectively. They are connected all together, and create helixes. In DNA, there are 2 (hence double helix), and on each side there is one, so the 2 “pair up”. If there is an A on one side there is always a T on the other, and vice versa. If there is a G on one side there is always a C on the other. When DNA is used, it is first converted into RNA in the nucleus, then the RNA leaves and can “communicate” with the ribosome. The ribosome reads the RNA and by proxy the DNA in groups of 3 called triplets or codons. The ribosome only makes proteins, and each codon can say 1 amino acid, that the ribosome will have to make to the amino acids in that order (the order of the codons/triplets), then other forces (hydrophobia, polarity, electrons, ect) will fold the protein in to the desired shape. The protein will then go on to do whatever it needs with its new shape (shape is very important for proteins, oftentimes its shape is critical to its function).
The pentose sugar is also important in a nucleotide. Its “3’ hydroxyl group” connects to the phosphorus from other nucleotides (in DNA) to create a chain and make usable instructions. The pentose sugar is what creates the structure of the nucleotide and holds everything together.
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The phosphorus part of a nucleotide is especially important in ATP (adenosine triphosphate). In DNA it only connects the nucleotide to the next, but on ATP it is a store of energy. The triphosphate part tells us that the 3 phosphate groups “don’t like” being near each other, and this is a chemical store of potential energy, as when the option arises, one of the phosphate groups will shoot off, releasing energy, before a H2O molecule takes it place, and forms the much more stable ADP (adenosine diphosphate), before it can be “recharged” through ADP synthase and an inorganic phosphate.
Works Cited
Baker, Susan S., and Robert D. Baker. “Enteric Versus Parenteral Feeding and Mucosal Function.” Immunophysiology of the Gut, 1993, pp. 401–14, https://doi.org/10.1016/b978-0-12-732085-4.50035-7. Accessed 22 Oct. 2026.
Wikipedia Contributors. “DNA.” Wikipedia, Wikimedia Foundation, 31 Jan. 2019, en.wikipedia.org/wiki/DNA. Accessed 22 Oct. 2026.
— — — . “Nucleotide.” Wikipedia, Wikimedia Foundation, 15 May 2019, en.wikipedia.org/wiki/Nucleotide. Accessed 22 Oct. 2026.
your genome. “What Is RNA?” Www.Yourgenome.Org, www.yourgenome.org/theme/what-is-rna/. Accessed 22 Oct. 2026.
