Denaturation

Lots of molecules contain H⁺ ions as part of their structure. When in solution with acids (which are H⁺ ion donors) these molecules may gain the extra H⁺ ions within their structure.

Similarly when molecules are in solution with alkalis or bases, which are both H⁺ ion acceptors, molecules may lose their H⁺ ions.

Removal or addition of H⁺ ions alters a molecule’s shape and structure. This is known as denaturation.

Denaturation can result in permanent or temporary changes to a molecule’s structure. If changes are temporary then restoration of the pH will return the molecule to its original shape.