what causes denaturation in proteins distinquish between permanently and temporarily denatured proteins
It's a structural alteration of the active site of a protein, rendering it incapable of functioning. Depending on the protein molecule concerned and the circumstances surrounding the denaturation, it can be either temporary or permanent.
Common causes of denaturation are the application of excessive heat or contact with acids/alkalis.
Certain other substances may inhibit or destroy protein functionality. Hydrogen cyanide, for example, bonds permanently to the active site of the proteins responsible for cellular respiration, rendering them useless