Question

what is the term for the unraveling of enzymes when they are heated or exposed to a ph out of their optimal range? how does it affect the ability of a protein to function?

Explanation:

Enzymes are proteins. When heated or exposed to non - optimal pH, the process is called denaturation. Denaturation disrupts the protein's 3D structure (secondary, tertiary, or quaternary). Proteins' functions depend on their structure (e.g., enzyme - substrate binding). If the structure is lost (denatured), the protein (e.g., enzyme) can't bind substrates (or perform other functions like structural support for structural proteins) properly, so it loses its function.

Answer:

The term is denaturation. Denaturation causes the protein to lose its function as its structure (necessary for function) is disrupted.