Which statement describes the sugar component of nucleotides?

Which statement describes the sugar component of nucleotides?

• A. Hexose sugar
• B. Disaccharide
• C. Polysaccharide
• D. Pentose sugar

Answer: (D)

Nucleotides are built from a five-carbon sugar, a phosphate group, and a nitrogenous base, so the sugar component is a pentose. In DNA the sugar is deoxyribose, and in RNA it is ribose; both are five-carbon sugars, which is why we describe the sugar part as a pentose. This contrasts with hexose sugars (six carbons) and with disaccharides or polysaccharides (pairs or long chains of sugars)—those refer to different types of carbohydrate forms, not the single sugar that links the phosphate backbone to the base in a nucleotide. The essential point is that nucleotides use a five-carbon sugar, fitting the term pentose.

Nucleotides are built from a five-carbon sugar, a phosphate group, and a nitrogenous base, so the sugar component is a pentose. In DNA the sugar is deoxyribose, and in RNA it is ribose; both are five-carbon sugars, which is why we describe the sugar part as a pentose. This contrasts with hexose sugars (six carbons) and with disaccharides or polysaccharides (pairs or long chains of sugars)—those refer to different types of carbohydrate forms, not the single sugar that links the phosphate backbone to the base in a nucleotide. The essential point is that nucleotides use a five-carbon sugar, fitting the term pentose.