In Biochemistry, the primary structure of a Biomolécule not-ramified like a bit of DNA, ARN or a Protein, is the sequence of amino-acid Nucléotide or of the beginning at the end of the molecule. In other words, the primary structure identifies exact the chemical composition and the sequence of its sub-units monomeric S.

The primary structure of a biological polymer largely determines the known three-dimensional form under the name of tertiary Structure. However the folding up of the nucleic acid and proteins is so complex that often even by knowing the primary education structure that does not help to deduce the form from it or to predict the secondary structure, such as the formations of layers or propellers. However, knowing the structure of a similar homologous sequence (for example a member of the same family of protein) allows without ambiguity to identify the tertiary structure of a given sequence. Families of sequences are often determined by clustering of sequence, and by the structural projects of genomic which aim at producing a whole of representative structures to cover the sequential space of possible not-redundant sequence.

See too

• secondary Structure
• tertiary Structure