kvartäärirakenne

Kvartäärirakenne refers to the three-dimensional arrangement of the polypeptide chains within a protein molecule. While primary structure describes the linear sequence of amino acids and secondary structure deals with local folding patterns like alpha-helices and beta-sheets, tertiary structure is the overall, complex, folded shape of a single polypeptide chain. This intricate folding is stabilized by various interactions between amino acid side chains, including hydrogen bonds, ionic bonds, hydrophobic interactions, and disulfide bridges. These interactions determine the unique three-dimensional conformation of the protein, which is crucial for its biological function. A protein's tertiary structure dictates its active site, its ability to bind to other molecules, and its overall stability. Any alteration to this structure, often due to changes in the environment like temperature or pH, or through mutations in the amino acid sequence, can lead to denaturation and loss of function.