Question

Explain the difference in structure between a nucleoside and a nucleotide.

Short answer

The main difference in structure between a nucleoside and a nucleotide lies in the presence or absence of the phosphate group. Both nucleosides and nucleotides consist of a nitrogenous base and a sugar molecule; however, nucleotides also contain one or more phosphate groups attached to the sugar component, making them the building blocks of nucleic acids such as DNA and RNA.

Step-by-step solution

Describe a nucleoside

A nucleoside is an organic molecule that consists of a nitrogenous base and a sugar (typically a ribose or a deoxyribose sugar) covalently linked together. The nitrogenous base can be either a purine (adenine or guanine) or a pyrimidine (cytosine, thymine, or uracil). The sugar and nitrogenous base are connected through a glycosidic bond. Ribonucleosides consist of ribose sugar, while deoxyribonucleosides use deoxyribose sugar.

Describe a nucleotide

A nucleotide is an organic molecule that consists of three components: a nitrogenous base, a sugar, and a phosphate group. Similar to nucleosides, the nitrogenous base can be a purine or a pyrimidine, and the sugar can be a ribose or a deoxyribose. The sugar and nitrogenous base are connected through a glycosidic bond, while the sugar is connected to the phosphate group through a phosphoester bond. Nucleotides are the building blocks of nucleic acids, such as DNA and RNA.

Highlight the difference in structure between a nucleoside and a nucleotide

The main difference between a nucleoside and a nucleotide lies in the presence or absence of the phosphate group. While both nucleosides and nucleotides contain a nitrogenous base and a sugar, nucleotides also have one or more phosphate groups attached to the sugar component.

Summarize the difference

In summary, the primary structural difference between a nucleoside and a nucleotide is the presence of a phosphate group in nucleotides. Both nucleosides and nucleotides contain a nitrogenous base and a sugar, but nucleotides also include a phosphate group linked to the sugar molecule, making them the basic units of nucleic acids.