The tertiary structure of a protein refers to its three-dimensional shape, which is crucial for its function. This structure is formed by the folding and interactions of the protein's amino acids, including hydrogen bonds, ionic bonds, and hydrophobic interactions. The specific arrangement of these interactions determines how the protein will behave in biological processes. Understanding tertiary structure is essential in fields like biochemistry and molecular biology, as it influences how proteins interact with other molecules. Misfolding of proteins can lead to diseases, highlighting the importance of proper tertiary structure in maintaining cellular function and overall health.