After which of the following treatments (I-III) would an enzyme still be expected to have activity? I. Protease treatment. II. Heating almost to the point of denaturation. III. Freezing and then thawing once only.

Step-by-step solution

Protease enzymes have catalytic function. When this is added to other enzymes it will catalyse the peptide bonds of the enzymes and thus will result in denaturation of the enzymes. Similarly heating the enzymes will also increase the temperature and this will result in denaturation too because enzymes are active only at optimum temperatures and beyond it there will not be any function. However freezing has no effect on enzyme activity as it does not affect the peptide bonds.