Nucleotide structure

• Nucleic acids are made up of basic units called nucleotides, each nucleotide is made up of:

  • A phosphate
  • A ribose sugar
  • A base

  
• Nucleotides bind together through condensation reactions to form a polynucleotide
• Condensation reactions also join each nucleotide together between the phosphate group of one and a carbon of the pentose sugar of the other

  • This bond is known as a phosphodiester bond
• How RNA is different from DNA:

  • The sugar in RNA is ribose, not deoxyribose
• How RNA is different from DNA:

  • The nucleotide strand in RNA is a single strand, not double
• Diagram:

  Polynucleotide - A polymer composed of several nucleotides linked together

  
• Which molecules make up the 'backbone' of a polynucleotide?

  Phosphates and Pentose sugars
• Cytosine and Uracil consist of one ring and are known as pyrimidines
• A condensation reaction between two nucleotide forms a phosphodiester bond

  • The continued linking of nucleotides in this way forms a long chain known as a polynucleotide