Nucleotide

Definition

A nucleotide is the basic building block of nucleic acids, such as DNA and RNA. It consists of a nitrogenous base, a five-carbon sugar, and one or more phosphate groups.

5 Must Know Facts For Your Next Test

1. Nucleotides are composed of three components: a nitrogenous base (adenine, thymine, cytosine, guanine in DNA), a pentose sugar (deoxyribose in DNA), and phosphate groups.
2. In DNA, nucleotides are linked together by phosphodiester bonds to form the backbone of the double helix structure.
3. The sequence of nucleotides in DNA determines the genetic information carried by an organism.
4. Nucleotides play critical roles in cellular metabolism and energy transfer, for example, ATP is a nucleotide that stores and transfers energy within cells.
5. Mutations in the sequence of nucleotides can lead to genetic disorders or changes in phenotype.

Review Questions

• What are the three main components of a nucleotide?
• How do nucleotides link together in DNA?
• Why are mutations in nucleotide sequences significant?

Related terms

DNA:

Deoxyribonucleic acid, the molecule that carries genetic information.

RNA:

Ribonucleic acid, involved in protein synthesis and gene expression.

Phosphodiester Bond:

A chemical bond that links successive sugar molecules in a polynucleotide chain.