Fundamentals of Molecular Biology - V.I. Rezyapkin 2009

Nucleic Acids
Primary Structure of Nucleic Acids

The primary Structure of Nucleic Acids refers to The sequence of NUCLEOTIDES in a polynucleotide chain (Fig. 1.1). In DNA and RNA molecules, nucleotides are linked together by phosphodiester bridges between the 3’- and 5’-carbon atoms of the pentose residues.

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Fig. 1.1. Introduction/19.html">Primary Structure of Nucleic Acids

DNA and RNA chains have 5’ and 3’ ends (Fig. 1.1). Nucleotide numbering is performed in the 5’-to-3’ direction. The nucleotide sequence in a single-stranded DNA and RNA is written in this same direction.



Last update: 12/08/2026

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