Which of the following is NOT a component of a nucleotide?

A nucleotide is the basic building block of nucleic acids, which include DNA and RNA. Each nucleotide comprises three critical components: a sugar molecule (either ribose in RNA or deoxyribose in DNA), a nitrogenous base (which can be adenine, guanine, cytosine, thymine for DNA, or uracil for RNA), and phosphate groups that can range from one to three in number, depending on whether it is a nucleoside monophosphate, diphosphate, or triphosphate.

The correct answer highlights that an amino acid is not a part of a nucleotide. Amino acids are the building blocks of proteins, and while they play a crucial role in the overall function of cells and organisms, they do not form part of the nucleotide structure. This distinction is key in understanding the different roles that nucleotides and amino acids play in cellular biology.