The primary structure of a protein refers to its unique sequence of amino acids. This sequence is determined by the genetic code found in DNA. Each amino acid is linked together by peptide bonds, forming a long chain. The specific order of these amino acids is crucial, as it dictates how the protein will fold and function. The primary structure is the first level of protein organization, preceding secondary, tertiary, and quaternary structures. Any changes or mutations in the amino acid sequence can lead to altered protein function, which may result in various diseases. Understanding primary structure is essential in fields like biochemistry and molecular biology.