DNA

and comparable to a long chain, DNA belongs to the category of nucleic acids, that is, large biological molecules (macromolecules) formed by smaller molecular units that are called nucleotides.
A generic nucleotide that forms DNA comprises 3 elements: a phosphate group, sugar deoxyribose and a nitrogenous base.
Organized in chromosomes, DNA is used for the generation of proteins, which play a fundamental role in regulating all the cellular mechanisms of an organism.

of most living organs, including humans.