Nucleotides: Structure and Functions
Start with the big picture
A nucleotide consists of a purine or pyrimidine base, ribose or deoxyribose, and at least one phosphate. The base attaches to the sugar through an N-glycosidic bond, while phosphate connects to the sugar through a phosphoester bond; additional phosphates are joined by phosphoanhydride bonds. The sugar and phosphate groups shape important chemical properties, including the difference between DNA and RNA sugars and the negative charge of phosphates. Base complementarity helps explain pairing in nucleic acids. Nucleotides also serve as energy carriers, signaling molecules, coenzyme components, activated intermediates, and metabolic regulators. Their synthesis, salvage, and breakdown have clinical relevance, including in antimetabolite action, gout, and Lesch–Nyhan syndrome.
What you'll learn
- Identify the three components of a nucleotide and distinguish purines from pyrimidines.
- Describe the bonds linking bases, sugars, and phosphate groups.
- Explain how nucleotide structure supports base pairing and nucleic-acid function.
- Recognize major nucleotide roles in energy transfer, signaling, and metabolism.
- Relate purine metabolism and nucleotide analogues to selected clinical conditions.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
