Which of the following is a component of a nucleotide?

A nucleotide is a fundamental building block of nucleic acids, such as DNA and RNA, and consists of three main components: a phosphate group, a nitrogenous base, and a sugar. The sugar in a nucleotide can be either ribose (in RNA) or deoxyribose (in DNA). This sugar is crucial as it forms part of the backbone of the nucleic acid structure, linking to the phosphate group and to the nitrogenous base, which encodes genetic information.

The other components mentioned, such as amino acids, proteins, and fatty acids, are related to different biological macromolecules and processes. Amino acids are the building blocks of proteins, fatty acids are components of lipids, and proteins are made from long chains of amino acids. However, they do not play a role in the structure of nucleotides. Therefore, the sugar component is fundamental to the architecture and function of nucleotides, making it the correct answer in this context.