Final answer:
The specificity of enzymes is explained by the influence their levels of protein conformation have on their three-dimensional shape, which is critical for substrate binding at the enzyme's active site.
Step-by-step explanation:
The levels of conformation of proteins help to explain the specificity of enzymes by influencing their three-dimensional shape (B). The three-dimensional shape determines how an enzyme interacts with its specific substrate, with the active site's shape being particularly important. This shape compatibility is essential for the enzyme's ability to bind to the substrate and catalyze reactions efficiently. The underlying connection between protein structure and function lies within the four levels of protein structure: primary, secondary, tertiary, and quaternary.
Each level contributes to the final shape of the protein. The primary structure, which is the sequence of amino acids, dictates how the chain can fold and form bonds. Secondary structures like α-helices and β-sheets arise from hydrogen bonds between the backbone components of the polypeptide chain. These secondary elements fold further into a tertiary structure, stabilized by various interactions and bonds between side chains. If a protein is made up of multiple polypeptide chains, the arrangement of these chains in space constitutes the quaternary structure. The intricacy of these structures and their non-covalent interactions, both weak and strong, underscore the complexity and specificity of enzyme function.
The induced-fit model of enzyme action elaborates that an enzyme's active site undergoes a conformational change when the substrate binds, emphasizing the dynamic nature of the enzyme's conformation.