What monomer units make up DNA?

DNA is composed of monomer units known as nucleotides. Each nucleotide consists of three components: a phosphate group, a five-carbon sugar (deoxyribose in the case of DNA), and a nitrogenous base (which can be adenine, thymine, cytosine, or guanine). These nucleotides link together through phosphodiester bonds to form the long polymer chains that constitute the DNA molecule.

Understanding the structure of nucleotides is critical in biology and genetics, as they are not only the building blocks of DNA but also play roles in cellular processes, such as energy transfer and signal transduction, particularly in their forms like ATP (adenosine triphosphate). This foundational knowledge is crucial for topics such as heredity, genetic variation, and biotechnology.

The other options represent different classes of macromolecules: amino acids are the building blocks of proteins, monosaccharides are simple sugars that form carbohydrates, and fatty acids are components of lipids. Each serves distinct roles in biological systems, but they do not comprise the structure of DNA. Thus, nucleotides are uniquely integral to the formation of DNA.