What is the primary structure of a protein?

The primary structure of a protein refers to its specific sequence of amino acids. This sequence is determined by the genetic code and dictates how the protein will fold and function. Each amino acid is linked together by peptide bonds to form a polypeptide chain, and the order in which these amino acids are arranged is crucial because it influences the protein's higher-level structures—the secondary, tertiary, and quaternary structures.

The primary structure is the foundational level of protein organization. Variations in this sequence can lead to proteins with different shapes and functions, which is significant in biological processes. Any alteration, even a single amino acid change, can affect the protein's overall functionality and stability, highlighting the importance of this sequence. This is why the correct identification of the primary structure as the sequence of amino acids is fundamental in understanding protein biology.