Living cells cannot use heat to provide the activation energy for biochemical reactions because which choice(s) complete the sentence correctly?

Considering the following;

I. Heat is not readily available to all living cells.

II. Heat at excessive amounts denatures proteins.

III. Heat does not provide the activation energy for their reactions.

IV. When a critical temperature is reached, proteins no longer function

Answer;

I and IV

Explanation;

Living cells cannot use heat to provide the activation energy for biochemical reactions because heat is not readily available to all living cells and also when a critical temperature is reached, proteins no longer function.

Too much heat can kill an organism by rendering its organelles, cells, tissues and organs permanently inoperable and un-salvageable. The same process can be observed in tissues at low temperatures, and is the cause of frostbite. This is because enzymes are denatured by high temperature and inactivated by low.