Which term describes a molecule that consists of sugar, phosphate, and nitrogenous base?

Which term describes a molecule that consists of sugar, phosphate, and nitrogenous base?

• A. Nucleoside
• B. Nucleotide
• C. Base
• D. Polynucleotide

Answer: (B)

Think of the fundamental unit of nucleic acids: a nucleotide. It is a single molecule made of three parts—a five‑carbon sugar (deoxyribose in DNA or ribose in RNA), a phosphate group, and a nitrogenous base. This combination is what identifies a nucleotide, and when nucleotides link together they form the long polymers of DNA and RNA through phosphodiester bonds in the backbone. A nucleoside, by contrast, has only the sugar and base (no phosphate), a base is just one component, and a polynucleotide is a chain consisting of many nucleotides. So the molecule described as containing sugar, phosphate, and a nitrogenous base is a nucleotide.

Think of the fundamental unit of nucleic acids: a nucleotide. It is a single molecule made of three parts—a five‑carbon sugar (deoxyribose in DNA or ribose in RNA), a phosphate group, and a nitrogenous base. This combination is what identifies a nucleotide, and when nucleotides link together they form the long polymers of DNA and RNA through phosphodiester bonds in the backbone. A nucleoside, by contrast, has only the sugar and base (no phosphate), a base is just one component, and a polynucleotide is a chain consisting of many nucleotides. So the molecule described as containing sugar, phosphate, and a nitrogenous base is a nucleotide.