Why do living things use enzymes instead of heat as a source of activation energy? adding heat would not give the reactants enough energy. adding heat does not affect how chemical reactions take place. adding sufficient heat would harm or kill a living thing. adding heat gives reactants the wrong kind of energy.

Adding sufficient heat would harm or kill a living thing.

Living things use enzymes instead of a heat source because they speed up chemical reactions as well as the metabolism in those living. Adding sufficient heat would harm or kill a living thing, also enzymes are far more efficient. A single enzyme can often carry out thousands of reactions per second. Living organisms use enzymes for activation energy because they speed up chemical reactions.